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Search found 327 results on 14 pages for 'openjdk'.

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  • Crazy idea: Connect .NET and SAP with SAP JCo using IKVM.NET

    - by Kottan
    Because the SAP Connector for .NET is no longer maintained by SAP, I am now looking for an alternative to connect the Microsoft world with the SAP world. I know there a third party products like ERPConnect, but I want to do this with tools from SAP. Therefore there arised the crazy idea to use the SAP Java Connector in combination with the tool IKVM.NET (www.ikvm.net/devguide/net2java.html). IKVM.NET provides The IKVMC tool, which converts Java bytecode to .NET dll's and exe's. "No sooner said than done!" I converted the SAP JCo to .NET dlls and created a new Visual Studio solution. I put all the JCO files into a subdirectory of my solution. I set 2 references to the generated IKVM.OpenJDK.Core.dll and sapjco.dll. Great, all JCO classes where now available as .NET classes. Full of optimism I wrote some little code to connect to a SAP system. JCO.Client client = null; client = JCO.createClient(...) The compiliation of my testcode had no errors. "Wonderful !" I thought. Then I started my tetstapplication. Unfortunately I got an exception calling JCO.createClient: Could not load middleware layer 'com.sap.mw.jco.rfc.MiddlewareRFC'\r\nno sapjcorfc in java.library.path I have 2 questions on this topic. 1) Do you think my idea using SAP Java Connector to connect .NET with SAP is a good idea or is it nonsens ? Perhaps someone had already the same idea ;-) 2) How can the above exception be solved ?

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  • TLS with SNI in Java clients

    - by ftrotter
    There is an ongoing discussion on the security and trust working group for NHIN Direct regarding the IP-to-domain mapping problem that is created with traditional SSL. If an HISP (as defined by NHIN Direct) wants to host thousands of NHIN Direct "Health Domains" for providers, then it will an "artificially inflated cost" to have to purchase an IP for each of those domains. Because Apache and OpenSSL have recently released TLS with support for the SNI extension, it is possible to use SNI as a solution to this problem on the server side. However, if we decide that we will allow server implementations of the NHINDirect transport layer to support TLS+SNI, then we must require that all clients support SNI too. OpenSSL based clients should do this by default and one could always us stunnel to implement an TLS+SNI aware client to proxy if your given programming language SSL implementation does not support SNI. It appears that native Java applications using OpenJDK do not yet support SNI, but I cannot get a straight answer out of that project. I know that there are OpenSSL Java libraries available but I have no idea if that would be considered viable. Can you give me a "state of the art" summary of where TLS+SNI support is for Java clients? I need a Java implementers perspective on this.

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  • Trouble implementing Singleton pattern in Tomcat web application due to Class Loader

    - by jwegan
    I'm trying to implement a Singleton in Tomcat 6.24 on Linux with x86_64 OpenJDK 1.6. My application is just a bunch of JSPs and some static content and the JSPs make calls to my Java code. Currently the web.xml just looks like this: <web-app xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd" version="2.5"> <description> App Name </description> <display-name>App Name</display-name> <!-- The Usual Welcome File List --> <welcome-file-list> <welcome-file>pages/index.jsp</welcome-file> </welcome-file-list> </web-app> Before when I was trying to load my Singleton it was getting instantiated twice since the class was getting loaded by two different class loaders (I'm not sure why) and each loader would create an instance of the singleton which is not acceptable for my application. I finally figured out if I exported my code as a jar and put it in $CATALINA_HOME/lib then there was only one instance, but this is not an elegant solution. I've been googling for hours, but I haven't come up with anything yet. I'm wondering if there is some other solution. Currently I'm not precompling my JSPs, could this be part of the problem? Could I write a servlet to ensure the singleton is created? If so how do I do that?

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  • Writing a synchronized thread-safety wrapper for NavigableMap

    - by polygenelubricants
    java.util.Collections currently provide the following utility methods for creating synchronized wrapper for various collection interfaces: synchronizedCollection(Collection<T> c) synchronizedList(List<T> list) synchronizedMap(Map<K,V> m) synchronizedSet(Set<T> s) synchronizedSortedMap(SortedMap<K,V> m) synchronizedSortedSet(SortedSet<T> s) Analogously, it also has 6 unmodifiedXXX overloads. The glaring omission here are the utility methods for NavigableMap<K,V>. It's true that it extends SortedMap, but so does SortedSet extends Set, and Set extends Collection, and Collections have dedicated utility methods for SortedSet and Set. Presumably NavigableMap is a useful abstraction, or else it wouldn't have been there in the first place, and yet there are no utility methods for it. So the questions are: Is there a specific reason why Collections doesn't provide utility methods for NavigableMap? How would you write your own synchronized wrapper for NavigableMap? Glancing at the source code for OpenJDK version of Collections.java seems to suggest that this is just a "mechanical" process Is it true that in general you can add synchronized thread-safetiness feature like this? If it's such a mechanical process, can it be automated? (Eclipse plug-in, etc) Is this code repetition necessary, or could it have been avoided by a different OOP design pattern?

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  • Swing modal dialog refuses to close - sometimes!

    - by Zarkonnen
    // This is supposed to show a modal dialog and then hide it again. In practice, // this works about 75% of the time, and the other 25% of the time, the dialog // stays visible. // This is on Ubuntu 10.10, running: // OpenJDK Runtime Environment (IcedTea6 1.9) (6b20-1.9-0ubuntu1) // This always prints // setVisible(true) about to happen // setVisible(false) about to happen // setVisible(false) has just happened // even when the dialog stays visible. package modalproblemdemo; import java.awt.Frame; import javax.swing.JDialog; import javax.swing.SwingUtilities; public class Main { public static void main(String[] args) { final Dialogs d = new Dialogs(); new Thread() { @Override public void run() { d.show(); d.hide(); } }.start(); } static class Dialogs { final JDialog dialog; public Dialogs() { dialog = new JDialog((Frame) null, "Hello World", /*modal*/ true); dialog.setSize(400, 200); } public void show() { SwingUtilities.invokeLater(new Runnable() { public void run() { dialog.setLocationRelativeTo(null); System.out.println("setVisible(true) about to happen"); dialog.setVisible(true); }}); } public void hide() { SwingUtilities.invokeLater(new Runnable() { public void run() { System.out.println("setVisible(false) about to happen"); dialog.setVisible(false); System.out.println("setVisible(false) has just happened"); }}); } } }

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  • Why is Scala's type inferencer not able to resolve this?

    - by Levi Greenspan
    In the code snippet below - why do I have to give a type annotation for Nil? Welcome to Scala version 2.8.0.RC2 (OpenJDK Server VM, Java 1.6.0_18). Type in expressions to have them evaluated. Type :help for more information. scala> List(Some(1), Some(2), Some(3), None).foldLeft(Nil)((lst, o) => o match { case Some(i) => i::lst; case None => lst }) <console>:6: error: type mismatch; found : List[Int] required: object Nil List(Some(1), Some(2), Some(3), None).foldLeft(Nil)((lst, o) => o match { case Some(i) => i::lst; case None => lst }) ^ scala> List(Some(1), Some(2), Some(3), None).foldLeft(Nil:List[Int])((lst, o) => o match { case Some(i) => i::lst; case None => lst }) res1: List[Int] = List(3, 2, 1)

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  • Elasticsearch won't start anymore

    - by Oleander
    I restarted my elasticsearch instance 5 days ago and I haven't manage to start it since then. I get no output in the log file /var/log/elasticsearch/ nor does the elasticsearch binary print any information when running at using elasticsearch -f. I once manage to get this output. [2012-11-15 22:51:18,427][INFO ][node ] [Piper] {0.19.11}[29584]: initializing ... [2012-11-15 22:51:18,433][INFO ][plugins ] [Piper] loaded [], sites [] Running curl http://localhost:9200 resulted in curl: (7) couldn't connect to host. I've tried increasing the memory from 3gb to 10gb, but that didn't make any diffrence. Running /etc/init.d/elasticsearch start takes 30 seconds. ps aux | grep elasticsearch results in this output. /usr/local/share/elasticsearch/bin/service/exec/elasticsearch-linux-x86-64 /usr/local/share/elasticsearch/bin/service/elasticsearch.conf wrapper.syslog.ident=elasticsearch wrapper.pidfile=/usr/local/share/elasticsearch/bin/service/./elasticsearch.pid wrapper.name=elasticsearch wrapper.displayname=ElasticSearch wrapper.daemonize=TRUE wrapper.statusfile=/usr/local/share/elasticsearch/bin/service/./elasticsearch.status wrapper.java.statusfile=/usr/local/share/elasticsearch/bin/service/./elasticsearch.java.status wrapper.script.version=3.5.14 /usr/lib/jvm/java-7-openjdk-amd64/jre/bin/java -Delasticsearch-service -Des.path.home=/usr/local/share/elasticsearch -Xss256k -XX:+UseParNewGC -XX:+UseConcMarkSweepGC -XX:CMSInitiatingOccupancyFraction=75 -XX:+UseCMSInitiatingOccupancyOnly -XX:+HeapDumpOnOutOfMemoryError -Djava.awt.headless=true -Xms1024m -Xmx1024m -Djava.library.path=/usr/local/share/elasticsearch/bin/service/lib -classpath /usr/local/share/elasticsearch/bin/service/lib/wrapper.jar:/usr/local/share/elasticsearch/lib/elasticsearch-0.19.11.jar:/usr/local/share/elasticsearch/lib/elasticsearch-0.19.11.jar:/usr/local/share/elasticsearch/lib/jna-3.3.0.jar:/usr/local/share/elasticsearch/lib/log4j-1.2.17.jar:/usr/local/share/elasticsearch/lib/lucene-analyzers-3.6.1.jar:/usr/local/share/elasticsearch/lib/lucene-core-3.6.1.jar:/usr/local/share/elasticsearch/lib/lucene-highlighter-3.6.1.jar:/usr/local/share/elasticsearch/lib/lucene-memory-3.6.1.jar:/usr/local/share/elasticsearch/lib/lucene-queries-3.6.1.jar:/usr/local/share/elasticsearch/lib/snappy-java-1.0.4.1.jar:/usr/local/share/elasticsearch/lib/sigar/sigar-1.6.4.jar -Dwrapper.key=k7r81VpK3_Bb3N_5 -Dwrapper.port=32000 -Dwrapper.jvm.port.min=31000 -Dwrapper.jvm.port.max=31999 -Dwrapper.disable_console_input=TRUE -Dwrapper.pid=23888 -Dwrapper.version=3.5.14 -Dwrapper.native_library=wrapper -Dwrapper.service=TRUE -Dwrapper.cpu.timeout=10 -Dwrapper.jvmid=1 org.tanukisoftware.wrapper.WrapperSimpleApp org.elasticsearch.bootstrap.ElasticSearchF My current system: ElasticSearch Version: 0.19.11, JVM: 23.2-b09 Ubuntu 12.04 LTS I've tried re-install elasticsearch, removing old directories. Why can't I get it to start?

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  • Trouble setting up PATH for Java on Debian

    - by milkmansrevenge
    I am trying to get Oracle Java 7 update 3 working correctly on Debian 6. I have downloaded and set up the files in /usr/java/jre1.7.0_03. I have also set the following two lines at the end of /etc/bash.bashrc: export JAVA_HOME=/usr/java/jre1.7.0_03 export PATH=$PATH:$JAVA_HOME/bin Logging in as other users and root is fine, Java can be found: chris@mc:~$ java -version java version "1.7.0_03" Java(TM) SE Runtime Environment (build 1.7.0_03-b04) Java HotSpot(TM) 64-Bit Server VM (build 22.1-b02, mixed mode) However there are two cases where Java cannot be found as detailed below. Note that both of these worked fine when I have previously installed OpenJDK Java 6 via aptitude, but I need Oracle Java 7 for various reasons. Most importantly, I cannot run commands as another user via su, despite the PATH showing that Java should be present. The user was created with adduser chris root@mc:~# su chris -c "echo $PATH" /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/java/jre1.7.0_03/bin:/bin root@mc:~# su chris -c "java -version" bash: java: command not found root@mc:~# su chris -c "/usr/java/jre1.7.0_03/bin/java -version" java version "1.7.0_03" ... How can it be in the PATH but not be found? Update 05/04/2012: explained by Daniel, to do with it being a non-interactive shell so files such as /etc/profile and /etc/bash.bashrc are not executed. Doing a full swap to that user and running Java works: root@mc:~# su chris chris@mc:/root$ java -version java version "1.7.0_03" ... I run a script on start up which exhibits similar but slightly different problems. The script is located in /etc/init.d/start-mystuff.sh and calls a jar: #!/bin/bash # /etc/init.d/start-mystuff.sh java -jar /opt/Mars.jar I can confirm that the script runs on start up and the exit code is 127, which indicates command not found. Inserting a line to print/save the PATH shows that it is: /sbin:/usr/sbin:/bin:/usr/bin This second problem isn't as important because I can just point directly to the Java executable in the script, but I am still curious! I have tried setting the full PATH and JAVA_HOME explicitly in /etc/environment which didn't help. I have also tried setting them in /etc/profile which doesn't seem to help either. I have tried logging in and out again after setting PATH in the various locations (duh!). Anyway, long post for what will probably have a simple one line solution :( Any help with this would be greatly appreciated, I have spent far too long trying to fix it by myself. Motivation The first problem may seem obscure but in my system I have users that are not allowed SSH access yet I still want to run processes as them. I have a ton of scripts operating in this way and don't want to have to change them all.

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  • jenkins-maven-android when running throwing the error "android-sdk-linux/platforms" is not a directory"

    - by Sam
    I start setting up the jenkins-maven-android and i'm facing an issue when running the jenkin job. My Machine Details $uname -a Linux development2 3.0.0-12-virtual #20-Ubuntu SMP Fri Oct 7 18:19:02 UTC 2011 x86_64 x86_64 x86_64 GNU/Linux Steps to install the Android SDK in Ubuntu https://help.ubuntu.com/community/AndroidSDK since i'm working on headless env (ssh to client machine) i used following command to install the platform tools android update sdk --no-ui download apache maven and install on http://maven.apache.org/download.html mvn -version output root@development2:/opt/android-sdk-linux/tools# mvn -version Apache Maven 3.0.4 (r1232337; 2012-01-17 08:44:56+0000) Maven home: /opt/apache-maven-3.0.4 Java version: 1.6.0_24, vendor: Sun Microsystems Inc. Java home: /usr/lib/jvm/java-6-openjdk/jre Default locale: en_US, platform encoding: UTF-8 OS name: "linux", version: "3.0.0-12-virtual", arch: "amd64", family: "unix" root@development2:/opt/android-sdk-linux/tools# ran the following two command as mention in below sudo apt-get update sudo apt-get install ia32-libs Problems with Eclipse and Android SDK http://developer.android.com/sdk/installing/index.html As error suggest i gave the path to android SDK in jenkins build config still im getting the error clean install -Dandroid.sdk.path=/opt/android-sdk-linux Can someone help me to resolve this. Thanks Error I'm Getting Waiting for Jenkins to finish collecting data mavenExecutionResult exceptions not empty message : Failed to execute goal com.jayway.maven.plugins.android.generation2:android-maven-plugin:3.1.1:generate-sources (default-generate-sources) on project base-template: Execution default-generate-sources of goal com.jayway.maven.plugins.android.generation2:android-maven-plugin:3.1.1:generate-sources failed: Path "/opt/android-sdk-linux/platforms" is not a directory. Please provide a proper Android SDK directory path as configuration parameter <sdk><path>...</path></sdk> in the plugin <configuration/>. As an alternative, you may add the parameter to commandline: -Dandroid.sdk.path=... or set environment variable ANDROID_HOME. cause : Execution default-generate-sources of goal com.jayway.maven.plugins.android.generation2:android-maven-plugin:3.1.1:generate-sources failed: Path "/opt/android-sdk-linux/platforms" is not a directory. Please provide a proper Android SDK directory path as configuration parameter <sdk><path>...</path></sdk> in the plugin <configuration/>. As an alternative, you may add the parameter to commandline: -Dandroid.sdk.path=... or set environment variable ANDROID_HOME. Stack trace : org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal com.jayway.maven.plugins.android.generation2:android-maven-plugin:3.1.1:generate-sources (default-generate-sources) on project base-template: Execution default-generate-sources of goal com.jayway.maven.plugins.android.generation2:android-maven-plugin:3.1.1:generate-sources failed: Path "/opt/android-sdk-linux/platforms" is not a directory. Please provide a proper Android SDK directory path as configuration parameter <sdk><path>...</path></sdk> in the plugin <configuration/>. As an alternative, you may add the parameter to commandline: -Dandroid.sdk.path=... or set environment variable ANDROID_HOME. at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:225) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:84) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:59) at org.apache.maven.lifecycle.internal.LifecycleStarter.singleThreadedBuild(LifecycleStarter.java:183) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:161) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:320) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:156) at org.jvnet.hudson.maven3.launcher.Maven3Launcher.main(Maven3Launcher.java:79) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:616) at org.codehaus.plexus.classworlds.launcher.Launcher.launchStandard(Launcher.java:329) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:239) at org.jvnet.hudson.maven3.agent.Maven3Main.launch(Maven3Main.java:158) at hudson.maven.Maven3Builder.call(Maven3Builder.java:98) at hudson.maven.Maven3Builder.call(Maven3Builder.java:64) at hudson.remoting.UserRequest.perform(UserRequest.java:118) at hudson.remoting.UserRequest.perform(UserRequest.java:48) at hudson.remoting.Request$2.run(Request.java:326) at hudson.remoting.InterceptingExecutorService$1.call(InterceptingExecutorService.java:72) at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334) at java.util.concurrent.FutureTask.run(FutureTask.java:166) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603) at java.lang.Thread.run(Thread.java:679) Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default-generate-sources of goal com.jayway.maven.plugins.android.generation2:android-maven-plugin:3.1.1:generate-sources failed: Path "/opt/android-sdk-linux/platforms" is not a directory. Please provide a proper Android SDK directory path as configuration parameter <sdk><path>...</path></sdk> in the plugin <configuration/>. As an alternative, you may add the parameter to commandline: -Dandroid.sdk.path=... or set environment variable ANDROID_HOME. at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:110) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:209) ... 27 more Caused by: com.jayway.maven.plugins.android.InvalidSdkException: Path "/opt/android-sdk-linux/platforms" is not a directory. Please provide a proper Android SDK directory path as configuration parameter <sdk><path>...</path></sdk> in the plugin <configuration/>. As an alternative, you may add the parameter to commandline: -Dandroid.sdk.path=... or set environment variable ANDROID_HOME. at com.jayway.maven.plugins.android.AndroidSdk.assertPathIsDirectory(AndroidSdk.java:125) at com.jayway.maven.plugins.android.AndroidSdk.getPlatformDirectories(AndroidSdk.java:285) at com.jayway.maven.plugins.android.AndroidSdk.findAvailablePlatforms(AndroidSdk.java:260) at com.jayway.maven.plugins.android.AndroidSdk.<init>(AndroidSdk.java:80) at com.jayway.maven.plugins.android.AbstractAndroidMojo.getAndroidSdk(AbstractAndroidMojo.java:844) at com.jayway.maven.plugins.android.phase01generatesources.GenerateSourcesMojo.generateR(GenerateSourcesMojo.java:329) at com.jayway.maven.plugins.android.phase01generatesources.GenerateSourcesMojo.execute(GenerateSourcesMojo.java:102) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:101) ... 28 more channel stopped Finished: FAILURE* android home Echo root@development2:~# echo $ANDROID_HOME /opt/android-sdk-linux

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  • Installing Matlab on ubuntu 12.04 32 bits

    - by Amir
    I have been trying to install Matlab2012a, matlab2012b and Matlab2013a for like 4 hours, triedto fix my prospective errors regarding the posts 2012a, Ubuntu-Matlab Documentation and Matlab-central. But either i am recieving an error while the installation GUI pops-up with the error : The application encountered an unexpected error and needs to close. You may want to try re-installing your product(s). More information can be found at /tmp/mathworks_amir.log On the other hand for 2012a. and the errors for 2012b and 2013a is : `Installing ... Exception in thread "main" com.google.inject.ProvisionException: Guice provision errors: 1) Error in custom provider, java.lang.RuntimeException: java.lang.reflect.InvocationTargetException at com.mathworks.wizard.WizardModule.provideDisplayProperties(WizardModule.java:60) while locating com.mathworks.instutil.DisplayProperties at com.mathworks.wizard.ui.components.ComponentsModule.providePaintStrategy(ComponentsModule.java:76) while locating com.mathworks.wizard.ui.components.PaintStrategy for parameter 4 at com.mathworks.wizard.ui.components.SwingComponentFactoryImpl.(SwingComponentFactoryImpl.java:110) while locating com.mathworks.wizard.ui.components.SwingComponentFactoryImpl while locating com.mathworks.wizard.ui.components.SwingComponentFactory for parameter 1 at com.mathworks.wizard.ui.WizardUIImpl.(WizardUIImpl.java:65) while locating com.mathworks.wizard.ui.WizardUIImpl while locating com.mathworks.wizard.ui.WizardUI annotated with @com.google.inject.name.Named(value=BaseWizardUI) at com.mathworks.wizard.ui.UIModule.provideWizardUI(UIModule.java:50) while locating com.mathworks.wizard.ui.WizardUI for parameter 0 at com.mathworks.wizard.ExceptionHandlerImpl.(ExceptionHandlerImpl.java:22) while locating com.mathworks.wizard.ExceptionHandlerImpl while locating com.mathworks.wizard.ExceptionHandler 1 error at com.google.inject.InjectorImpl$4.get(InjectorImpl.java:767) at com.google.inject.InjectorImpl.getInstance(InjectorImpl.java:793) at com.mathworks.wizard.WizardLauncher.startWizard(WizardLauncher.java:160) at com.mathworks.wizard.WizardLauncher.start(WizardLauncher.java:75) at com.mathworks.wizard.AbstractLauncher.launch(AbstractLauncher.java:27) at com.mathworks.wizard.AbstractLauncher.launchStandalone(AbstractLauncher.java:18) at com.mathworks.professionalinstaller.Launcher.main(Launcher.java:21) Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException at com.google.inject.internal.ProviderMethod.get(ProviderMethod.java:106) at com.google.inject.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:48) at com.google.inject.InjectorImpl$4$1.call(InjectorImpl.java:758) at com.google.inject.InjectorImpl.callInContext(InjectorImpl.java:811) at com.google.inject.InjectorImpl$4.get(InjectorImpl.java:754) at com.google.inject.spi.ProviderLookup$1.get(ProviderLookup.java:89) at com.google.inject.spi.ProviderLookup$1.get(ProviderLookup.java:89) at com.google.inject.internal.ProviderMethod.get(ProviderMethod.java:95) at com.google.inject.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:48) at com.google.inject.SingleParameterInjector.inject(SingleParameterInjector.java:42) at com.google.inject.SingleParameterInjector.getAll(SingleParameterInjector.java:66) at com.google.inject.ConstructorInjector.construct(ConstructorInjector.java:84) at com.google.inject.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:111) at com.google.inject.FactoryProxy.get(FactoryProxy.java:56) at com.google.inject.SingleParameterInjector.inject(SingleParameterInjector.java:42) at com.google.inject.SingleParameterInjector.getAll(SingleParameterInjector.java:66) at com.google.inject.ConstructorInjector.construct(ConstructorInjector.java:84) at com.google.inject.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:111) at com.google.inject.FactoryProxy.get(FactoryProxy.java:56) at com.google.inject.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:45) at com.google.inject.InjectorImpl.callInContext(InjectorImpl.java:811) at com.google.inject.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:42) at com.google.inject.Scopes$1$1.get(Scopes.java:54) at com.google.inject.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:48) at com.google.inject.InjectorImpl$4$1.call(InjectorImpl.java:758) at com.google.inject.InjectorImpl.callInContext(InjectorImpl.java:811) at com.google.inject.InjectorImpl$4.get(InjectorImpl.java:754) at com.google.inject.spi.ProviderLookup$1.get(ProviderLookup.java:89) at com.google.inject.spi.ProviderLookup$1.get(ProviderLookup.java:89) at com.google.inject.internal.ProviderMethod.get(ProviderMethod.java:95) at com.google.inject.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:48) at com.google.inject.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:45) at com.google.inject.InjectorImpl.callInContext(InjectorImpl.java:811) at com.google.inject.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:42) at com.google.inject.Scopes$1$1.get(Scopes.java:54) at com.google.inject.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:48) at com.google.inject.SingleParameterInjector.inject(SingleParameterInjector.java:42) at com.google.inject.SingleParameterInjector.getAll(SingleParameterInjector.java:66) at com.google.inject.ConstructorInjector.construct(ConstructorInjector.java:84) at com.google.inject.ConstructorBindingImpl$Factory.get(ConstructorBindingImpl.java:111) at com.google.inject.FactoryProxy.get(FactoryProxy.java:56) at com.google.inject.ProviderToInternalFactoryAdapter$1.call(ProviderToInternalFactoryAdapter.java:45) at com.google.inject.InjectorImpl.callInContext(InjectorImpl.java:811) at com.google.inject.ProviderToInternalFactoryAdapter.get(ProviderToInternalFactoryAdapter.java:42) at com.google.inject.Scopes$1$1.get(Scopes.java:54) at com.google.inject.InternalFactoryToProviderAdapter.get(InternalFactoryToProviderAdapter.java:48) at com.google.inject.InjectorImpl$4$1.call(InjectorImpl.java:758) at com.google.inject.InjectorImpl.callInContext(InjectorImpl.java:804) at com.google.inject.InjectorImpl$4.get(InjectorImpl.java:754) ... 6 more Caused by: java.lang.reflect.InvocationTargetException at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:606) at com.google.inject.internal.ProviderMethod.get(ProviderMethod.java:101) ... 54 more Caused by: com.mathworks.instutil.JNIException: java.lang.UnsatisfiedLinkError: Can't load library: /tmp/mathworks_7417/bin/glnxa64/libinstutil.so at com.mathworks.instutil.NativeUtility.loadNativeLibrary(NativeUtility.java:39) at com.mathworks.instutil.NativeUtility.(NativeUtility.java:24) at com.mathworks.instutil.DisplayPropertiesImpl.(DisplayPropertiesImpl.java:10) at com.mathworks.wizard.WizardModule.provideDisplayProperties(WizardModule.java:67) ... 59 more Caused by: java.lang.UnsatisfiedLinkError: Can't load library: /tmp/mathworks_7417/bin/glnxa64/libinstutil.so at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1842) at java.lang.Runtime.load0(Runtime.java:795) at java.lang.System.load(System.java:1061) at com.mathworks.instutil.NativeUtility.loadNativeLibrary(NativeUtility.java:37) ... 62 more Finished ` I have tried to 1- re-install java run-time 6 and then 7. 2- pass the java-path to the install with : -javadir 3- use the force to install on 32 bits as : sh install -glnx86 -v -javadir /usr/lib/jvm/java-7-openjdk-i386/jre But it seems none of them have worked so far. any ideas ??

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  • 7 reasons you had to be at JavaOne Latin America 2012

    - by Bruno.Borges
    Yesterday was 12/12/12, and everybody went crazy on Twitter with cool memes like this one. And maybe you are now wondering why I mentioned 7 (seven) on the blog title. Because I want to play numbers? Yes! Today is 7 days after JavaOne Latin America 2012 is over (... and I had to figure out an excuse for taking so long to blog about it...). So unless you were at JavaOne Latin America this year, here are 7 things you missed: OTN Lounge mini-theatreThere was a mini-theatre holding several lightning talks. We had people from SouJava JUG, GoJava JUG, Globalcode, and several other Java gurus and companies running demos, talks, and even more. For example, @drspockbr talked about the ScrumToys project, that demonstrates the power of JSF. Hands On Lab for JAX-RS and WebSocketsOne of the cool things to do during JavaOne is to come to these Hands On labs and really do something using new technologies with the help of experts. This one in particular, was covered by me, Arun Gupta, and Reza Rahman. The HOL had more people than laptops (and we had 48 laptops!) interested on understanding and learning about the new stuff that is coming within Java EE 7. Things like JAX-RS, Server-sent Events and WebSockets. Hey, if you want to try this HOL by yourself, it is available on Github, so go for it! If you have questions, just let me know! Java Community KeynoteThis keynote presented a lot of cool things like startups using Java in their projects, the Duke Awards, SouJava winning the JCP Outstanding Award, the Java Band, and even more! It was really a space where the Java community could present what they are doing and what they want to do. There's a lot of interest on the Adopt-a-JSR program and the Adopt-OpenJDK. There's also an Adopt-a-JavaEE-JSR program! Take a look if you want to participate and Make the Future Java. Java EE (JMS, JAX-RS) sessions from Reza Rahman, the HeavyMetal guyReza is a well know professional and Java EE enthusiast from the communitty who just joined Oracle this year. His sessions were very well attended, perhaps because of a high interest on the new things coming to Java EE 7 like JMS 2.0 and JAX-RS 2.0. If you want to look at what he did at this JavaOne edition, read his blog post. By the way, if you like Java and heavymetal, you should follow him on Twitter as well! :-) Java EE (WebSockets, HTML5) sessions from Arun Gupta, the GlassFish guyIf you don't know Arun Gupta, no worries. You will have time to know about him while you read his Java EE 6 Pocket Guide. Arun has been evangelizing Java EE for a long time, and is now spreading his word about the new upcoming version Java EE 7. He gave one talk about HTML5 Productivity on the Java EE 7 platform, and another one on building web apps with WebSockets. Pretty neat! Arun blogged about JavaOne Latin America as well. Read it here. Java Embedded and JavaFXIf there are two things that are really trending in the Java World right now besides Java EE 7, certainly they are JavaFX and Java Embedded. There were 14 talks covering Java Embedded, from Java Cards to Raspberry.pi, from Java ME to Java on your TV with Ginga-J. The Internet of Things is becoming true, and Java is the only platform today that can connect it all in an standardized and concise way. JavaFX gained a lot of attention too. There were 8 sessions covering what the platform has to offer in terms of Rich User Experience. The JavaFX Scene Builder is an awesome tool to start playing designing an UI, and coding for JavaFX is like coding Swing with 8 hands, one holding your coffee cup. You can achieve a lot, with your two hands (unless, you really have 8 hands, then you can achieve 4 times more :-). If you want to read more about JavaFX, go to Stephen Chin's blog post. GlassFish and Friends Party, 1st edition at JavaOne Lating AmericaThis is probably the thing that I'm most proud. We brought to Brasil the tradition of holding a happy hour for all GlassFish, Java EE friends. This party started almost 7 years ago in San Francisco, and it was about time to bring it to Brazil! The party happened on Tuesday night, right after JavaOne General Keynote, at the Tribeca Pub. We had about 80 attendees and met a lot of Java EE developers there! People from JUGs, Oracle, Locaweb and Red Hat showed up too, including some execs from Oracle that didn't resist and could not miss a party like this one.Lots of caipirinhas, beer and food to everyone, some cool music... even The Fish walking around the party with Juggy!You can see more photos from the party on an album I shared with the recently created GlassFish Brasil community on Google+ here (but you may be more interested in joining the GlassFish english community). There's also more pictures that Arun took and shared on this link. So now you may want to consider coming to Brazil next year! Java EE 7 is on its way, and Brazil is happily and patiently waiting for it, with a lot of enthusiasm. By the way, GlassFish and Java EE 6 just celebrated a Happy Birthday!

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  • Goto for the Java Programming Language

    - by darcy
    Work on JDK 8 is well-underway, but we thought this late-breaking JEP for another language change for the platform couldn't wait another day before being published. Title: Goto for the Java Programming Language Author: Joseph D. Darcy Organization: Oracle. Created: 2012/04/01 Type: Feature State: Funded Exposure: Open Component: core/lang Scope: SE JSR: 901 MR Discussion: compiler dash dev at openjdk dot java dot net Start: 2012/Q2 Effort: XS Duration: S Template: 1.0 Reviewed-by: Duke Endorsed-by: Edsger Dijkstra Funded-by: Blue Sun Corporation Summary Provide the benefits of the time-testing goto control structure to Java programs. The Java language has a history of adding new control structures over time, the assert statement in 1.4, the enhanced for-loop in 1.5,and try-with-resources in 7. Having support for goto is long-overdue and simple to implement since the JVM already has goto instructions. Success Metrics The goto statement will allow inefficient and verbose recursive algorithms and explicit loops to be replaced with more compact code. The effort will be a success if at least twenty five percent of the JDK's explicit loops are replaced with goto's. Coordination with IDE vendors is expected to help facilitate this goal. Motivation The goto construct offers numerous benefits to the Java platform, from increased expressiveness, to more compact code, to providing new programming paradigms to appeal to a broader demographic. In JDK 8, there is a renewed focus on using the Java platform on embedded devices with more modest resources than desktop or server environments. In such contexts, static and dynamic memory footprint is a concern. One significant component of footprint is the code attribute of class files and certain classes of important algorithms can be expressed more compactly using goto than using other constructs, saving footprint. For example, to implement state machines recursively, some parties have asked for the JVM to support tail calls, that is, to perform a complex transformation with security implications to turn a method call into a goto. Such complicated machinery should not be assumed for an embedded context. A better solution is just to expose to the programmer the desired functionality, goto. The web has familiarized users with a model of traversing links among different HTML pages in a free-form fashion with some state being maintained on the side, such as login credentials, to effect behavior. This is exactly the programming model of goto and code. While in the past this has been derided as leading to "spaghetti code," spaghetti is a tasty and nutritious meal for programmers, unlike quiche. The invokedynamic instruction added by JSR 292 exposes the JVM's linkage operation to programmers. This is a low-level operation that can be leveraged by sophisticated programmers. Likewise, goto is a also a low-level operation that should not be hidden from programmers who can use more efficient idioms. Some may object that goto was consciously excluded from the original design of Java as one of the removed feature from C and C++. However, the designers of the Java programming languages have revisited these removals before. The enum construct was also left out only to be added in JDK 5 and multiple inheritance was left out, only to be added back by the virtual extension method methods of Project Lambda. As a living language, the needs of the growing Java community today should be used to judge what features are needed in the platform tomorrow; the language should not be forever bound by the decisions of the past. Description From its initial version, the JVM has had two instructions for unconditional transfer of control within a method, goto (0xa7) and goto_w (0xc8). The goto_w instruction is used for larger jumps. All versions of the Java language have supported labeled statements; however, only the break and continue statements were able to specify a particular label as a target with the onerous restriction that the label must be lexically enclosing. The grammar addition for the goto statement is: GotoStatement: goto Identifier ; The new goto statement similar to break except that the target label can be anywhere inside the method and the identifier is mandatory. The compiler simply translates the goto statement into one of the JVM goto instructions targeting the right offset in the method. Therefore, adding the goto statement to the platform is only a small effort since existing compiler and JVM functionality is reused. Other language changes to support goto include obvious updates to definite assignment analysis, reachability analysis, and exception analysis. Possible future extensions include a computed goto as found in gcc, which would replace the identifier in the goto statement with an expression having the type of a label. Testing Since goto will be implemented using largely existing facilities, only light levels of testing are needed. Impact Compatibility: Since goto is already a keyword, there are no source compatibility implications. Performance/scalability: Performance will improve with more compact code. JVMs already need to handle irreducible flow graphs since goto is a VM instruction.

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  • Adopt-a-JSR for Java EE 7 - Getting Started

    - by arungupta
    Adopt-a-JSR is an initiative started by JUG leaders to encourage JUG members to get involved in a JSR, in order to increase grass roots participation. This allows JUG members to provide early feedback to specifications before they are finalized in the JCP. The standards in turn become more complete and developer-friendly after getting feedback from a wide variety of audience. adoptajsr.org provide more details about the logistics and benefits for you and your JUG. A similar activity was conducted for OpenJDK as well. Markus Eisele also provide a great introduction to the program (in German). Java EE 7 (JSR 342) is scheduled to go final in Q2 2013. There are several new JSRs that are getting included in the platform (e.g. WebSocket, JSON, and Batch), a few existing ones are getting an overhaul (e.g. JAX-RS 2 and JMS 2), and several other getting minor updates (e.g. JPA 2.1 and Servlets 3.1). Each Java EE 7 JSR can leverage your expertise and would love your JUG to adopt a JSR. What does it mean to adopt a JSR ? Your JUG is going to identify a particular JSR, or multiple JSRs, that is of interest to the JUG members. This is mostly done by polling/discussing on your local JUG members list. Your JUG will download and review the specification(s) and javadocs for clarity and completeness. The complete set of Java EE 7 specifications, their download links, and EG archives are listed here. glassfish.org/adoptajsr provide specific areas where different specification leads are looking for feedback. Your JUG can then think of a sample application that can be built using the chosen specification(s). An existing use case (from work or a personal hobby project) may be chosen to be implemented instead. This is where your creativity and uniqueness comes into play. Most of the implementations are already integrated in GlassFish 4 and others will be integrated soon. You can also explore integration of multiple technologies and provide feedback on the simplicity and ease-of-use of the programming model. Especially look for integration with existing Java EE technologies and see if you find any discrepancies. Report any missing features that may be included in future release of the specification. The most important part is to provide feedback by filing bugs on the corresponding spec or RI project. Any thing that is not clear either in the spec or implementation should be filed as a bug. This is what will ensure that specification and implementation leads are getting the required feedback and improving the quality of the final deliverable of the JSR. How do I get started ? A simple way to get started can be achieved by following S.M.A.R.T. as explained below. Specific Identify who all will be involved ? What would you like to accomplish ? For example, even though building a sample app will provide real-world validity of the API but because of time constraints you may identify that reviewing the specification and javadocs only can be accomplished. Establish a time frame by which the activities need to be complete. Measurable Define a success for metrics. For example, this could be the number of bugs filed. Remember, quality of bugs is more important that quantity of bugs. Define your end goal, for example, reviewing 4 chapters of the specification or completing the sample application. Create a dashboard that will highlight your JUG's contribution to this effort. Attainable Make sure JUG members understand the time commitment required for providing feedback. This can vary based upon the level of involvement (any is good!) and the number of specifications picked. adoptajsr.org defines different categories of involvement. Once again, any level of involvement is good. Just reviewing a chapter, a section, or javadocs for your usecase is helpful. Relevant Pick JSRs that JUG members are willing and able to work. If the JUG members are not interested then they might loose motivation half-way through. The "able" part is tricky as you can always stretch yourself and learn a new skill ;-) Time-bound Define a time table of activities with clearly defined tasks. A tentative time table may look like: Dec 25: Discuss and agree upon the specifications with JUG Jan 1: Start Adopt-a-JSR for Java EE 7 Jan 15: Initial spec reading complete. Keep thinking through the application that will be implemented. Jan 22: Early design of the sample application is ready Jan 29: JUG members agree upon the application Next 4 weeks: Implement the application Of course, you'll need to alter this based upon your commitment. Maintaining an activity dashboard will help you monitor and track the progress. Make sure to keep filing bugs through out the process! 12 JUGs from around the world (SouJava, Campinas JUG, Chennai JUG, London Java Community, BeJUG, Morocco JUG, Peru JUG, Indonesia JUG, Congo JUG, Silicon Valley JUG, Madrid JUG, and Houston JUG) have already adopted one of the Java EE 7 JSRs. I'm already helping some JUGs bootstrap and would love to help your JUG too. What are you waiting for ?

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  • The first day of JavaOne is already over!

    - by delabassee
    In the past Sunday used to be a more relaxing day with ‘just’ some JavaOne activities going on. Sunday used to be a soft day to prepare yourself for an exhausting week. This is now over as JavaOne is expanding; Sunday is now an integral part of the conference. One of the side effect of this extra day is that some activities related to JavaOne and OpenWorld such as MySQL Connect are being push to start a day earlier on Saturday (can you spot the pattern here?). On the GlassFish front, Sunday was a very busy day! It started at the Moscone Center with the annual GlassFish Community Event where the Java EE 7 and GF 4 roadmaps were presented and discussed. During the event, different GlassFish users such as ZeroTurnaround (the JRebel guys), Grupo RBS and IDR Solutions shared their views on GF, why they like GF but also what could be improved. The event was also a forum for the GF community to exchange with some of the key Java EE / GlassFish Oracle Executives and the different GF team members. The Strategy keynote and the Technical keynote were held in the Masonic Auditorium later in the after-noon. Oracle executives have presented the plans for Java SE, Java FX and Java EE. As on-demand replays will be available soon, I will not summarize several hours of content but here are some personal takeaways from those keynotes. Modularity Modularity is a big deal. We know by now that Project Jigsaw will not be ready for Java SE 8 but in any case, it is already possible (and encouraged) to test Jigsaw today. In the future, Java EE plan to rely on the modularity features provided by Java SE, so Project Jigsaw is also relevant for Java EE developers. Shorter term, to cover some of the modular requirements, Java SE will adopt the approach that was used for Java EE 6 and the notion of Profiles. This approach does not define a module system per say; Profiles is a way to clearly define different subsets of Java SE to fulfill different needs (e.g. the full JRE is not required for a headless application). The introduction of different Profiles, from the Base profile (10mb) to the Full Profile (+50mb), has been proposed for Java SE 8. Embedded Embedded is a strong theme going forward for the Java Plaform. There is now a dedicated program : Java Embedded @ JavaOne Java by nature (e.g. platform independence, built-in security, ability easily talks to any back-end systems, large set of skills available on the market, etc.) is probably the most suited platform for the Internet of Things. You can quickly be up-to-speed and develop services and applications for that space just by using your current Java skills. All you need to start developing on ARM is a 35$ Raspberry Pi ARM board (25$ if you are cheap and can live without an ethernet connection) and the recently released JDK for Linux/ARM. Obviously, GlassFish runs on Raspberry Pi. If you wan to go further in the embedded space, you should take a look Java SE Embedded, an optimized, low footprint, Java environment that support the major embedded architectures (ARM, PPC and x86). Finally, Oracle has recently introduced Java Embedded Suite, a new solution that brings modern middleware capabilities to the embedded space. Java Embedded Suite is an optimized solution that leverage Java SE Embedded but also GlassFish, Jersey and JavaDB to deploy advanced value added capabilities (eg. sensor data filtering and) deeper in the network, closer to the devices. JavaFX JavaFX is going strong! Starting from Java SE 7u6, JavaFX is bundled with the JDK. JavaFX is now available for all the major desktop platforms (Windows, Linux and Mac OS X). JavaFX is now also available, in developer preview, for low end device running Linux/ARM. During the keynote, JavaFX was shown running on a Raspberry Pi! And as announced during the keynote, JavaFX should be fully open-sourced by the end of the year; contributions are welcome!. There is a strong momentum around JavaFX, it’s the ideal client solution for the Java platform. A client layer that works perfectly with GlassFish on the back-end. If you were not convince by JavaFX, it’s time to reconsider it! As an old Chinese proverb say “One tweet is worth a thousand words!” HTML5, Project Avatar and Java EE 7 HTML5 got a lot of airtime too, it was covered during the Java EE 7 section of the keynote. Some details about Project Avatar, Oracle’s incubator project for a TSA (Thin Server Architecture) solution, were diluted and shown during the keynote. On the tooling side, Project Easel running on NetBeans 7.3 beta was demo’ed, including a cool NetBeans debugging session running in Chrome! HTML 5, Project Avatar and Java EE 7 deserve separate posts... Feedback We need your feedback! There are many projects, JSRs and products cooking : GlassFish 4, Project Jigsaw, Concurrency Utilities for Java EE (JSR 236), OpenJFX, OpenJDK to name just a few. Those projects, those specifications will have a profound impact on the Java platform for the years to come! So if you have the opportunity, download, install, learn, tests them and give feedback! Remember, you can "Make the Future Java!" Finally, the traditional GlassFish Party at the Thirsty Bear concluded the first JavaOne day. This party is another place where the community can freely exchange with the GlassFish team in a more relaxed, more friendly (but sometime more noisy) atmosphere. Arun has posted a set of pictures to reflect the atmosphere of the keynotes and the GlassFish party. You can find more details on the others Java EE and GlassFish activities here.

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  • JavaOne Latin America Opening Keynotes

    - by Tori Wieldt
    Originally published on blogs.oracle.com/javaone It was a great first day at JavaOne Brazil, which included the Java Strategy and Java Technical keynotes. Henrik Stahl, Senior Director, Product Management for Java opened the keynotes by saying that this is the third year for JavaOne Latin America. He explained, "You know what they say, the first time doesn't count, the second time is a habit and the third time it's a tradition!" He mentioned that he was thrilled that this is largest JavaOne in Brazil to date, and he wants next year to be larger. He said that Oracle knows Latin America is an important hub for development.  "We continually come back to Latin America because of the dedication the community has with driving the continued innovation for Java," he said. Stahl explained that Oracle and the Java community must continue to innovate and Make the Future Java together. The success of Java depends on three important factors: technological innovation, Oracle as a strong steward of Java, and community participation. "The Latin American Java Community (especially in Brazil) is a shining example of how to be positive contributor to Java," Stahl said. Next, George Saab, VP software dev, Java Platform Group at Oracle, discussed some of the recent and upcoming changes to Java. "In addition to the incremental improvements to Java 7, we have also increased the set of platforms supported by Oracle from Linux, Windows, and Solaris to now also include Mac OS X and Linux/ARM for ARM-based PCs such as the Raspberry Pi and emerging ARM based microservers."  Saab announced that EA builds for Linux ARM Hard Float ABI will be available by the end of the year.  Staffan Friberg, Product Manager, Java Platform Group, provided an overview of some of the language coming in Java 8, including Lambda, remove of PermGen, improved data and time APIs and improved security, Java 8 development is moving along. He reminded the audience that they can go to OpenJDK to see this development being done in real-time, and that there are weekly early access builds of OracleJDK 8 that developers can download and try today. Judson Althoff, Senior Vice President, Worldwide Alliances and Channels and Embedded Sales, was invited to the stage, and the audience was told that "even though he is wearing a suit, he is still pretty technical." Althoff started off with a bang: "The Internet of Things is on a collision course with big data and this is a huge opportunity for developers."  For example, Althoff said, today cars are more a data device than a mechanical device. A car embedded with sensors for fuel efficiency, temperature, tire pressure, etc. can generate a petabyte of data A DAY. There are similar examples in healthcare (patient monitoring and privacy requirements creates a complex data problem) and transportation management (sending a package around the world with sensors for humidity, temperature and light). Althoff then brought on stage representatives from three companies that are successful with Java today, first Axel Hansmann, VP Strategy & Marketing Communications, Cinterion. Mr. Hansmann explained that Cinterion, a market leader in Latin America, enables M2M services with Java. At JavaOne San Francisco, Cinterion launched the EHS5, the smallest 3g solderable module, with Java installed on it. This provides Original Equipment Manufacturers (OEMs) with a cost effective, flexible platform for bringing advanced M2M technology to market.Next, Steve Nelson, Director of Marketing for the Americas, at Freescale explained that Freescale is #1 in Embedded Processors in Wired and Wireless Communications, and #1 in Automotive Semiconductors in the Americas. He said that Java provides a mature, proven platform that is uniquely suited to meet the requirements of almost any type of embedded device. He encouraged University students to get involved in the Freescale Cup, a global competition where student teams build, program, and race a model car around a track for speed.Roberto Franco, SBTVD Forum President, SBTVD, talked about Ginga, a Java-based standard for television in Brazil. He said there are 4 million Ginga TV sets in Brazil, and they expect over 20 million TV sets to be sold by the end of 2014. Ginga is also being adopted in other 11 countries in Latin America. Ginga brings interactive services not only at TV set, but also on other devices such as tablets,  PCs or smartphones, as the main or second screen. "Interactive services is already a reality," he said, ' but in a near future, we foresee interactivity enhanced TV content, convergence with OTT services and a big participation from the audience,  all integrated on TV, tablets, smartphones and second screen devices."Before he left the stage, Nandini Ramani thanked Judson for being part of the Java community and invited him to the next Geek Bike Ride in Brazil. She presented him an official geek bike ride jersey.For the Technical Keynote, a "blue screen of death" appeared. With mock concern, Stephin Chin asked the rest of the presenters if they could go on without slides. What followed was a interesting collection of demos, including JavaFX on a tablet, a look at Project Easel in NetBeans, and even Simon Ritter controlling legos with his brainwaves! Stay tuned for more dispatches.

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  • JavaOne Latin America Opening Keynotes

    - by Tori Wieldt
    It was a great first day at JavaOne Brazil, which included the Java Strategy and Java Technical keynotes. Henrik Stahl, Senior Director, Product Management for Java opened the keynotes by saying that this is the third year for JavaOne Latin America. He explained, "You know what they say, the first time doesn't count, the second time is a habit and the third time it's a tradition!" He mentioned that he was thrilled that this is largest JavaOne in Brazil to date, and he wants next year to be larger. He said that Oracle knows Latin America is an important hub for development.  "We continually come back to Latin America because of the dedication the community has with driving the continued innovation for Java," he said. Stahl explained that Oracle and the Java community must continue to innovate and Make the Future Java together. The success of Java depends on three important factors: technological innovation, Oracle as a strong steward of Java, and community participation. "The Latin American Java Community (especially in Brazil) is a shining example of how to be positive contributor to Java," Stahl said. Next, George Saab, VP software dev, Java Platform Group at Oracle, discussed some of the recent and upcoming changes to Java. "In addition to the incremental improvements to Java 7, we have also increased the set of platforms supported by Oracle from Linux, Windows, and Solaris to now also include Mac OS X and Linux/ARM for ARM-based PCs such as the Raspberry Pi and emerging ARM based microservers."  Saab announced that EA builds for Linux ARM Hard Float ABI will be available by the end of the year.  Staffan Friberg, Product Manager, Java Platform Group, provided an overview of some of the language coming in Java 8, including Lambda, remove of PermGen, improved data and time APIs and improved security, Java 8 development is moving along. He reminded the audience that they can go to OpenJDK to see this development being done in real-time, and that there are weekly early access builds of OracleJDK 8 that developers can download and try today. Judson Althoff, Senior Vice President, Worldwide Alliances and Channels and Embedded Sales, was invited to the stage, and the audience was told that "even though he is wearing a suit, he is still pretty technical." Althoff started off with a bang: "The Internet of Things is on a collision course with big data and this is a huge opportunity for developers."  For example, Althoff said, today cars are more a data device than a mechanical device. A car embedded with sensors for fuel efficiency, temperature, tire pressure, etc. can generate a petabyte of data A DAY. There are similar examples in healthcare (patient monitoring and privacy requirements creates a complex data problem) and transportation management (sending a package around the world with sensors for humidity, temperature and light). Althoff then brought on stage representatives from three companies that are successful with Java today, first Axel Hansmann, VP Strategy & Marketing Communications, Cinterion. Mr. Hansmann explained that Cinterion, a market leader in Latin America, enables M2M services with Java. At JavaOne San Francisco, Cinterion launched the EHS5, the smallest 3g solderable module, with Java installed on it. This provides Original Equipment Manufacturers (OEMs) with a cost effective, flexible platform for bringing advanced M2M technology to market.Next, Steve Nelson, Director of Marketing for the Americas, at Freescale explained that Freescale is #1 in Embedded Processors in Wired and Wireless Communications, and #1 in Automotive Semiconductors in the Americas. He said that Java provides a mature, proven platform that is uniquely suited to meet the requirements of almost any type of embedded device. He encouraged University students to get involved in the Freescale Cup, a global competition where student teams build, program, and race a model car around a track for speed.Roberto Franco, SBTVD Forum President, SBTVD, talked about Ginga, a Java-based standard for television in Brazil. He said there are 4 million Ginga TV sets in Brazil, and they expect over 20 million TV sets to be sold by the end of 2014. Ginga is also being adopted in other 11 countries in Latin America. Ginga brings interactive services not only at TV set, but also on other devices such as tablets,  PCs or smartphones, as the main or second screen. "Interactive services is already a reality," he said, ' but in a near future, we foresee interactivity enhanced TV content, convergence with OTT services and a big participation from the audience,  all integrated on TV, tablets, smartphones and second screen devices."Before he left the stage, Nandini Ramani thanked Judson for being part of the Java community and invited him to the next Geek Bike Ride in Brazil. She presented him an official geek bike ride jersey.For the Technical Keynote, a "blue screen of death" appeared. With mock concern, Stephin Chin asked the rest of the presenters if they could go on without slides. What followed was a interesting collection of demos, including JavaFX on a tablet, a look at Project Easel in NetBeans, and even Simon Ritter controlling legos with his brainwaves! Stay tuned for more dispatches.

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  • Seven Random Thoughts on JavaOne

    - by HecklerMark
    As most people reading this blog may know, last week was JavaOne. There are a lot of summary/recap articles popping up now, and while I didn't want to just "add to pile", I did want to share a few observations. Disclaimer: I am an Oracle employee, but most of these observations are either externally verifiable or based upon a collection of opinions from Oracle and non-Oracle attendees alike. Anyway, here are a few take-aways: The Java ecosystem is alive and well, with a breadth and depth that is impossible to adequately describe in a short post...or a long post, for that matter. If there is any one area within the Java language or JVM that you would like to - or need to - know more about, it's well-represented at J1. While there are several IDEs that are used to great effect by the developer community, NetBeans is on a roll. I lost count how many sessions mentioned or used NetBeans, but it was by far the dominant IDE in use at J1. As a recent re-convert to NetBeans, I wasn't surprised others liked it so well, only how many. OpenJDK, OpenJFX, etc. Many developers were understandably concerned with the change of sponsorship/leadership when Java creator and longtime steward Sun Microsystems was acquired by Oracle. The read I got from attendees regarding Oracle's stewardship was almost universally positive, and the push for "openness" is deep and wide within the current Java environs. Few would probably have imagined it to be this good, this soon. Someone observed that "Larry (Ellison) is competitive, and he wants to be the best...so if he wants to have a community, it will be the best community on the planet." Like any company, Oracle is bound to make missteps, but leadership seems to be striking an excellent balance between embracing open efforts and innovating in competitive paid offerings. JavaFX (2.x) isn't perfect or comprehensive, but a great many people (myself included) see great potential, are developing for it, and are really excited about where it is and where it may be headed. This is another part of the Java ecosystem that has impressive depth for being so new (JavaFX 1.x aside). If you haven't kicked the tires yet, give it a try! You'll be surprised at how capable and versatile it is, and you'll probably catch yourself smiling while coding again.  :-) JavaEE is everywhere. Not exactly a newsflash, but there is a lot of buzz around EE still/again/anew. Sessions ranged from updated component specs/technologies to Websockets/HTML5, from frameworks to profiles and application servers. Programming "server-side" Java isn't confined to the server (as you no doubt realize), and if you still consider JavaEE a cumbersome beast, you clearly haven't been using the last couple of versions. Download GlassFish or the WebLogic Zip distro (or another JavaEE 6 implementation) and treat yourself. JavaOne is not inexpensive, but to paraphrase an old saying, "If you think that's expensive, you should try ignorance." :-) I suppose it's possible to attend J1 and learn nothing, but you'd have to really work at it! Attending even a single session is bound to expand your horizons and make you approach your code, your problem domain, differently...even if it's a session about something you already know quite well. The various presenters offer vastly different perspectives and challenge you to re-think your own approach(es). And finally, if you think the scheduled sessions are great - and make no mistake, most are clearly outstanding - wait until you see what you pick up from what I like to call the "hallway sessions". Between the presentations, people freely mingle in the hallways, go to lunch and dinner together, and talk. And talk. And talk. Ideas flow freely, sparking other ideas and the "crowdsourcing" of knowledge in a way that is hard to imagine outside of a conference of this magnitude. Consider this the "GO" part of a "BOGO" (Buy One, Get One) offer: you buy the ticket to the "structured" part of JavaOne and get the hallway sessions at no additional charge. They're really that good. If you weren't able to make it to JavaOne this year, you can still watch/listen to the sessions online by visiting the JavaOne course catalog and clicking the media link(s) in the right column - another demonstration of Oracle's commitment to the Java community. But make plans to be there next year to get the full benefit! You'll be glad you did. All the best,Mark P.S. - I didn't mention several other exciting developments in areas like the embedded space and the "internet of things" (M2M), robotics, optimization, and the cloud (among others), but I think you get the idea. JavaOne == brainExpansion;  Hope to see you there next year!

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  • Mouse wheel not scrolling in JDialog but working in JFrame

    - by Iulian Serbanoiu
    Hello, I'm facing a frustrating issue. I have an application where the scroll wheel doesn't work in a JDialog window (but works in a JFrame). Here's the code: import javax.swing.*; import java.awt.event.*; public class Failtest extends JFrame { public static void main(String[] args) { new Failtest(); } public Failtest() { super(); setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); setTitle("FRAME"); JScrollPane sp1 = new JScrollPane(getNewList()); add(sp1); setSize(150, 150); setVisible(true); JDialog d = new JDialog(this, false);// NOT WORKING //JDialog d = new JDialog((JFrame)null, false); // NOT WORKING //JDialog d = new JDialog((JDialog)null, false);// WORKING - WHY? d.setTitle("DIALOG"); d.setDefaultCloseOperation(JDialog.DISPOSE_ON_CLOSE); JScrollPane sp = new JScrollPane(getNewList()); d.add(sp); d.setSize(150, 150); d.setVisible(true); } public JList getNewList() { String objs[] = new String[30]; for(int i=0; i<objs.length; i++) { objs[i] = "Item "+i; } JList l = new JList(objs); return l; } } I found a solution which is present as a comment in the java code - the constructor receiving a (JDialog)null parameter. Can someone enlighten me? My opinion is that this is a java bug. Tested on Windows XP-SP3 with 1 JDK and 2 JREs: D:\Program Files\Java\jdk1.6.0_17\bin>javac -version javac 1.6.0_17 D:\Program Files\Java\jdk1.6.0_17\bin>java -version java version "1.6.0_17" Java(TM) SE Runtime Environment (build 1.6.0_17-b04) Java HotSpot(TM) Client VM (build 14.3-b01, mixed mode, sharing) D:\Program Files\Java\jdk1.6.0_17\bin>cd .. D:\Program Files\Java\jdk1.6.0_17>java -version java version "1.6.0_18" Java(TM) SE Runtime Environment (build 1.6.0_18-b07) Java HotSpot(TM) Client VM (build 16.0-b13, mixed mode, sharing) Thank you in advance, Iulian Serbanoiu PS: The problem is not new - the code is taken from a forum (here) where this problem was also mentioned - but no solutions to it (yet) LATER EDIT: The problem persists with jre/jdk_1.6.0_10, 1.6.0_16 also LATER EDIT 2: Back home, tested on linux (Ubuntu - lucid/lynx) - both with openjdk and sun-java from distribution repo and it works (I used the .class file compiled on Windows) !!! - so I believe I'm facing a JRE bug that happens on some Windows configurations.

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  • How do I use JDK 7 on Mac OSX?

    - by Yko
    OK. This is a newbie question but I can't figure it out... I would like to use the WatchService API as mentioned in this link: http://download.oracle.com/javase/tutorial/essential/io/notification.html After reading around, I found out that WatchService is part of the NIO class which is scheduled for JDK 7. So, it is in beta form. It's fine. http://jdk7.java.net/download.html has the JDK which I downloaded and extracted. I got a bunch of folders. I don't know what to do with them. Then, I read around some more and found that some nice group of people created JDK 7 as a binary so someone like me can install it easily. It is called Open JDK: http://code.google.com/p/openjdk-osx-build/ So, I downloaded the .dmg file and instal it. Then I open "Java Preference" and see that OpenJDK7 is available. So, now I feel that I can start trying out WatchService API. From the tutorial in the first link, the author gave a .java file to test it out first and make sure that it is running. Here is the link to the file: http://download.oracle.com/javase/tutorial/essential/io/examples/WatchDir.java So, I boot up Eclipse (actually I use STS) and create a new Java project and choose JaveSE-1.7 in the "use an execution environment JRE:". Under the src folder, I copy pasted the WatchDir.java file. And I still see tons of squiggly red lines. All the "import.java.nio.*" are all red and I cannot run it as a Java app. If you read this far, thanks a lot. So, now... What do I need to do? Thanks. EDIT: I actually did not pursue using Java 7 but there are a lot of interest in it and it seems like people keep answering this question. What should I do to make it more relevant to people who search for it? Let me know by PMing me. Thanks.

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  • Nashorn, the rhino in the room

    - by costlow
    Nashorn is a new runtime within JDK 8 that allows developers to run code written in JavaScript and call back and forth with Java. One advantage to the Nashorn scripting engine is that is allows for quick prototyping of functionality or basic shell scripts that use Java libraries. The previous JavaScript runtime, named Rhino, was introduced in JDK 6 (released 2006, end of public updates Feb 2013). Keeping tradition amongst the global developer community, "Nashorn" is the German word for rhino. The Java platform and runtime is an intentional home to many languages beyond the Java language itself. OpenJDK’s Da Vinci Machine helps coordinate work amongst language developers and tool designers and has helped different languages by introducing the Invoke Dynamic instruction in Java 7 (2011), which resulted in two major benefits: speeding up execution of dynamic code, and providing the groundwork for Java 8’s lambda executions. Many of these improvements are discussed at the JVM Language Summit, where language and tool designers get together to discuss experiences and issues related to building these complex components. There are a number of benefits to running JavaScript applications on JDK 8’s Nashorn technology beyond writing scripts quickly: Interoperability with Java and JavaScript libraries. Scripts do not need to be compiled. Fast execution and multi-threading of JavaScript running in Java’s JRE. The ability to remotely debug applications using an IDE like NetBeans, Eclipse, or IntelliJ (instructions on the Nashorn blog). Automatic integration with Java monitoring tools, such as performance, health, and SIEM. In the remainder of this blog post, I will explain how to use Nashorn and the benefit from those features. Nashorn execution environment The Nashorn scripting engine is included in all versions of Java SE 8, both the JDK and the JRE. Unlike Java code, scripts written in nashorn are interpreted and do not need to be compiled before execution. Developers and users can access it in two ways: Users running JavaScript applications can call the binary directly:jre8/bin/jjs This mechanism can also be used in shell scripts by specifying a shebang like #!/usr/bin/jjs Developers can use the API and obtain a ScriptEngine through:ScriptEngine engine = new ScriptEngineManager().getEngineByName("nashorn"); When using a ScriptEngine, please understand that they execute code. Avoid running untrusted scripts or passing in untrusted/unvalidated inputs. During compilation, consider isolating access to the ScriptEngine and using Type Annotations to only allow @Untainted String arguments. One noteworthy difference between JavaScript executed in or outside of a web browser is that certain objects will not be available. For example when run outside a browser, there is no access to a document object or DOM tree. Other than that, all syntax, semantics, and capabilities are present. Examples of Java and JavaScript The Nashorn script engine allows developers of all experience levels the ability to write and run code that takes advantage of both languages. The specific dialect is ECMAScript 5.1 as identified by the User Guide and its standards definition through ECMA international. In addition to the example below, Benjamin Winterberg has a very well written Java 8 Nashorn Tutorial that provides a large number of code samples in both languages. Basic Operations A basic Hello World application written to run on Nashorn would look like this: #!/usr/bin/jjs print("Hello World"); The first line is a standard script indication, so that Linux or Unix systems can run the script through Nashorn. On Windows where scripts are not as common, you would run the script like: jjs helloWorld.js. Receiving Arguments In order to receive program arguments your jjs invocation needs to use the -scripting flag and a double-dash to separate which arguments are for jjs and which are for the script itself:jjs -scripting print.js -- "This will print" #!/usr/bin/jjs var whatYouSaid = $ARG.length==0 ? "You did not say anything" : $ARG[0] print(whatYouSaid); Interoperability with Java libraries (including 3rd party dependencies) Another goal of Nashorn was to allow for quick scriptable prototypes, allowing access into Java types and any libraries. Resources operate in the context of the script (either in-line with the script or as separate threads) so if you open network sockets and your script terminates, those sockets will be released and available for your next run. Your code can access Java types the same as regular Java classes. The “import statements” are written somewhat differently to accommodate for language. There is a choice of two styles: For standard classes, just name the class: var ServerSocket = java.net.ServerSocket For arrays or other items, use Java.type: var ByteArray = Java.type("byte[]")You could technically do this for all. The same technique will allow your script to use Java types from any library or 3rd party component and quickly prototype items. Building a user interface One major difference between JavaScript inside and outside of a web browser is the availability of a DOM object for rendering views. When run outside of the browser, JavaScript has full control to construct the entire user interface with pre-fabricated UI controls, charts, or components. The example below is a variation from the Nashorn and JavaFX guide to show how items work together. Nashorn has a -fx flag to make the user interface components available. With the example script below, just specify: jjs -fx -scripting fx.js -- "My title" #!/usr/bin/jjs -fx var Button = javafx.scene.control.Button; var StackPane = javafx.scene.layout.StackPane; var Scene = javafx.scene.Scene; var clickCounter=0; $STAGE.title = $ARG.length>0 ? $ARG[0] : "You didn't provide a title"; var button = new Button(); button.text = "Say 'Hello World'"; button.onAction = myFunctionForButtonClicking; var root = new StackPane(); root.children.add(button); $STAGE.scene = new Scene(root, 300, 250); $STAGE.show(); function myFunctionForButtonClicking(){   var text = "Click Counter: " + clickCounter;   button.setText(text);   clickCounter++;   print(text); } For a more advanced post on using Nashorn to build a high-performing UI, see JavaFX with Nashorn Canvas example. Interoperable with frameworks like Node, Backbone, or Facebook React The major benefit of any language is the interoperability gained by people and systems that can read, write, and use it for interactions. Because Nashorn is built for the ECMAScript specification, developers familiar with JavaScript frameworks can write their code and then have system administrators deploy and monitor the applications the same as any other Java application. A number of projects are also running Node applications on Nashorn through Project Avatar and the supported modules. In addition to the previously mentioned Nashorn tutorial, Benjamin has also written a post about Using Backbone.js with Nashorn. To show the multi-language power of the Java Runtime, there is another interesting example that unites Facebook React and Clojure on JDK 8’s Nashorn. Summary Nashorn provides a simple and fast way of executing JavaScript applications and bridging between the best of each language. By making the full range of Java libraries to JavaScript applications, and the quick prototyping style of JavaScript to Java applications, developers are free to work as they see fit. Software Architects and System Administrators can take advantage of one runtime and leverage any work that they have done to tune, monitor, and certify their systems. Additional information is available within: The Nashorn Users’ Guide Java Magazine’s article "Next Generation JavaScript Engine for the JVM." The Nashorn team’s primary blog or a very helpful collection of Nashorn links.

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  • Twitter ?? Nashorn ????(??)

    - by Homma
    ???? Nashorn ? Java ??????? Twitter ???????????????????? JavaFX ??????????????? ????? ??? jlaskey ??? Nashorn Blog ????????????? https://blogs.oracle.com/nashorn/entry/nashorn_in_the_twitterverse_continued ???????? ?? Twitter ???????????????????????? JavaFX ??????????????????????????????? Nashorn ?? JavaFX ??????????????JavaFX ???????????????????????????????????????Nashorn ? Java ????????????????????????????????????(JavaFX ?????????????????????)? ?????????????????????????????????????????????? Twitter ????????????????????????? var twitter4j = Packages.twitter4j; var TwitterFactory = twitter4j.TwitterFactory; var Query = twitter4j.Query; function getTrendingData() { var twitter = new TwitterFactory().instance; var query = new Query("nashorn OR nashornjs"); query.since("2012-11-21"); query.count = 100; var data = {}; do { var result = twitter.search(query); var tweets = result.tweets; for each (var tweet in tweets) { var date = tweet.createdAt; var key = (1900 + date.year) + "/" + (1 + date.month) + "/" + date.date; data[key] = (data[key] || 0) + 1; } } while (query = result.nextQuery()); return data; } ??????????????????getTrendingData() ??????????????(??????????Nashorn ???????? OpenJDK ?????? 2012 ? 11 ? 21 ???)??????????????????????????????????? ????JavaFX ? BarChart ??????????? var javafx = Packages.javafx; var Stage = javafx.stage.Stage var Scene = javafx.scene.Scene; var Group = javafx.scene.Group; var Chart = javafx.scene.chart.Chart; var FXCollections = javafx.collections.FXCollections; var ObservableList = javafx.collections.ObservableList; var CategoryAxis = javafx.scene.chart.CategoryAxis; var NumberAxis = javafx.scene.chart.NumberAxis; var BarChart = javafx.scene.chart.BarChart; var XYChart = javafx.scene.chart.XYChart; var Series = javafx.scene.chart.XYChart.Series; var Data = javafx.scene.chart.XYChart.Data; function graph(stage, data) { var root = new Group(); stage.scene = new Scene(root); var dates = Object.keys(data); var xAxis = new CategoryAxis(); xAxis.categories = FXCollections.observableArrayList(dates); var yAxis = new NumberAxis("Tweets", 0.0, 200.0, 50.0); var series = FXCollections.observableArrayList(); for (var date in data) { series.add(new Data(date, data[date])); } var tweets = new Series("Tweets", series); var barChartData = FXCollections.observableArrayList(tweets); var chart = new BarChart(xAxis, yAxis, barChartData, 25.0); root.children.add(chart); } ????????????????????????????????stage.scene = new Scene(root) ? stage.setScene(new Scene(root)) ????????????????????Nashorn ? stage ??????? scene ???????????????????(Dynalink ?????????)Java Beans ???????????????? (setScene()) ???????????????????????????????Nashorn ? FXCollections ??????????????????????????????observableArrayList(dates) ??????????Nashorn ? JavaScript ??? (dates) ? Java ???????????????????????????? JavaScript ?????????????????? Java ????????????????????????????????????????????????????????????? ????????????????????????????????? JavaFX ???????????????????????? JavaFX ??????????????javafx.application.Application ??????????????????????????? JavaFX ????????????????????????????????????????????????? import java.io.IOException; import java.io.InputStream; import java.io.InputStreamReader; import javafx.application.Application; import javafx.stage.Stage; import javax.script.ScriptEngine; import javax.script.ScriptEngineManager; import javax.script.ScriptException; public class TrendingMain extends Application { private static final ScriptEngineManager MANAGER = new ScriptEngineManager(); private final ScriptEngine engine = MANAGER.getEngineByName("nashorn"); private Trending trending; public static void main(String[] args) { launch(args); } @Override public void start(Stage stage) throws Exception { trending = (Trending) load("Trending.js"); trending.start(stage); } @Override public void stop() throws Exception { trending.stop(); } private Object load(String script) throws IOException, ScriptException { try (final InputStream is = TrendingMain.class.getResourceAsStream(script)) { return engine.eval(new InputStreamReader(is, "utf-8")); } } } ???? Nashorn ??????? JSR-223 ? javax.script ????????? private static final ScriptEngineManager MANAGER = new ScriptEngineManager(); private final ScriptEngine engine = MANAGER.getEngineByName("nashorn"); ????????? JavaScript ???????? Nashorn ???????????????????? load ???????????????????????engine ???????????????load ????????????? ???????????????Java ???????????????????????????????????????????????????? Java ????????????????JavaFX ???????? start ????? stop ?????????????????????????????????????? public interface Trending { public void start(Stage stage) throws Exception; public void stop() throws Exception; } ?????????????????????????????? function newTrending() { return new Packages.Trending() { start: function(stage) { var data = getTrendingData(); graph(stage, data); stage.show(); }, stop: function() { } } } newTrending(); ?????? Trending ?????????????????????start ????? stop ??????????????????????????????????? eval ???? Java ??????????????? trending = (Trending) load("Trending.js"); ????????????????Trending.js ??????? getTrendingData ???????????? newTrending ????????????????????? Java ?????????newTrending ????????? eval ????????? Trending ????????????????????????????????????????????????????????? trending.start(stage); ???????? ???? Nashorn ????????? http://www.myexpospace.com/JavaOne2012/SessionFiles/CON5251_PDF_5251_0001.pdf ???????? Dynalink ??????? https://github.com/szegedi/dynalink ????????

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  • Cannot create Java VM on OpenVZ

    - by Stephen Searles
    I'm constantly encountering an error related to Java and certificates on my Ubuntu server running in OpenVZ when installing things from apt-get. I'm pretty sure it has to do with how Java allocates memory. I know the fail counter for privvmpages is very high, so the problem must be that Java is hitting this limit. I have read that the server VM will allocate a lot of memory up front to preempt performance issues, but that the client VM doesn't do this and might be better for what I'm doing. I messed with jvm.cfg to make the system go to the client VM, but get an error that it can't find the client VM. I have tried replacing the Java binary with a script calling Java with -Xms and -Xmx settings, and that solves the issue for when I call basic things from the command line, but not for when doing things like having apt-get configure certificates. I'm at a loss for what to try next. I need to get this working, but simply increasing privvmpages is not an available option. I have the actual error pasted below. Setting up ca-certificates-java (20100412) ... creating /etc/ssl/certs/java/cacerts... Could not create the Java virtual machine. error adding brasil.gov.br/brasil.gov.br.crt error adding cacert.org/cacert.org.crt error adding debconf.org/ca.crt error adding gouv.fr/cert_igca_dsa.crt error adding gouv.fr/cert_igca_rsa.crt error adding mozilla/ABAecom_=sub.__Am._Bankers_Assn.=_Root_CA.crt error adding mozilla/AOL_Time_Warner_Root_Certification_Authority_1.crt error adding mozilla/AOL_Time_Warner_Root_Certification_Authority_2.crt error adding mozilla/AddTrust_External_Root.crt error adding mozilla/AddTrust_Low-Value_Services_Root.crt error adding mozilla/AddTrust_Public_Services_Root.crt error adding mozilla/AddTrust_Qualified_Certificates_Root.crt error adding mozilla/America_Online_Root_Certification_Authority_1.crt error adding mozilla/America_Online_Root_Certification_Authority_2.crt error adding mozilla/Baltimore_CyberTrust_Root.crt error adding mozilla/COMODO_Certification_Authority.crt error adding mozilla/COMODO_ECC_Certification_Authority.crt error adding mozilla/Camerfirma_Chambers_of_Commerce_Root.crt error adding mozilla/Camerfirma_Global_Chambersign_Root.crt error adding mozilla/Certplus_Class_2_Primary_CA.crt error adding mozilla/Certum_Root_CA.crt error adding mozilla/Comodo_AAA_Services_root.crt error adding mozilla/Comodo_Secure_Services_root.crt error adding mozilla/Comodo_Trusted_Services_root.crt error adding mozilla/DST_ACES_CA_X6.crt error adding mozilla/DST_Root_CA_X3.crt error adding mozilla/DigiCert_Assured_ID_Root_CA.crt error adding mozilla/DigiCert_Global_Root_CA.crt error adding mozilla/DigiCert_High_Assurance_EV_Root_CA.crt Could not create the Java virtual machine. error adding mozilla/Digital_Signature_Trust_Co._Global_CA_1.crt error adding mozilla/Digital_Signature_Trust_Co._Global_CA_2.crt error adding mozilla/Digital_Signature_Trust_Co._Global_CA_3.crt error adding mozilla/Digital_Signature_Trust_Co._Global_CA_4.crt error adding mozilla/Entrust.net_Global_Secure_Personal_CA.crt error adding mozilla/Entrust.net_Global_Secure_Server_CA.crt error adding mozilla/Entrust.net_Premium_2048_Secure_Server_CA.crt error adding mozilla/Entrust.net_Secure_Personal_CA.crt error adding mozilla/Entrust.net_Secure_Server_CA.crt error adding mozilla/Entrust_Root_Certification_Authority.crt error adding mozilla/Equifax_Secure_CA.crt error adding mozilla/Equifax_Secure_Global_eBusiness_CA.crt error adding mozilla/Equifax_Secure_eBusiness_CA_1.crt error adding mozilla/Equifax_Secure_eBusiness_CA_2.crt error adding mozilla/Firmaprofesional_Root_CA.crt error adding mozilla/GTE_CyberTrust_Global_Root.crt error adding mozilla/GTE_CyberTrust_Root_CA.crt error adding mozilla/GeoTrust_Global_CA.crt error adding mozilla/GeoTrust_Global_CA_2.crt error adding mozilla/GeoTrust_Primary_Certification_Authority.crt error adding mozilla/GeoTrust_Universal_CA.crt error adding mozilla/GeoTrust_Universal_CA_2.crt error adding mozilla/GlobalSign_Root_CA.crt error adding mozilla/GlobalSign_Root_CA_-_R2.crt error adding mozilla/Go_Daddy_Class_2_CA.crt error adding mozilla/IPS_CLASE1_root.crt error adding mozilla/IPS_CLASE3_root.crt error adding mozilla/IPS_CLASEA1_root.crt error adding mozilla/IPS_CLASEA3_root.crt error adding mozilla/IPS_Chained_CAs_root.crt error adding mozilla/IPS_Servidores_root.crt error adding mozilla/IPS_Timestamping_root.crt error adding mozilla/NetLock_Business_=Class_B=_Root.crt error adding mozilla/NetLock_Express_=Class_C=_Root.crt error adding mozilla/NetLock_Notary_=Class_A=_Root.crt error adding mozilla/NetLock_Qualified_=Class_QA=_Root.crt error adding mozilla/Network_Solutions_Certificate_Authority.crt error adding mozilla/QuoVadis_Root_CA.crt error adding mozilla/QuoVadis_Root_CA_2.crt error adding mozilla/QuoVadis_Root_CA_3.crt error adding mozilla/RSA_Root_Certificate_1.crt error adding mozilla/RSA_Security_1024_v3.crt error adding mozilla/RSA_Security_2048_v3.crt error adding mozilla/SecureTrust_CA.crt error adding mozilla/Secure_Global_CA.crt error adding mozilla/Security_Communication_Root_CA.crt error adding mozilla/Sonera_Class_1_Root_CA.crt error adding mozilla/Sonera_Class_2_Root_CA.crt error adding mozilla/Staat_der_Nederlanden_Root_CA.crt error adding mozilla/Starfield_Class_2_CA.crt error adding mozilla/StartCom_Certification_Authority.crt error adding mozilla/StartCom_Ltd..crt error adding mozilla/SwissSign_Gold_CA_-_G2.crt error adding mozilla/SwissSign_Platinum_CA_-_G2.crt error adding mozilla/SwissSign_Silver_CA_-_G2.crt error adding mozilla/Swisscom_Root_CA_1.crt error adding mozilla/TC_TrustCenter__Germany__Class_2_CA.crt error adding mozilla/TC_TrustCenter__Germany__Class_3_CA.crt error adding mozilla/TDC_Internet_Root_CA.crt error adding mozilla/TDC_OCES_Root_CA.crt error adding mozilla/TURKTRUST_Certificate_Services_Provider_Root_1.crt error adding mozilla/TURKTRUST_Certificate_Services_Provider_Root_2.crt error adding mozilla/Taiwan_GRCA.crt error adding mozilla/Thawte_Personal_Basic_CA.crt error adding mozilla/Thawte_Personal_Freemail_CA.crt error adding mozilla/Thawte_Personal_Premium_CA.crt error adding mozilla/Thawte_Premium_Server_CA.crt error adding mozilla/Thawte_Server_CA.crt error adding mozilla/Thawte_Time_Stamping_CA.crt error adding mozilla/UTN-USER_First-Network_Applications.crt error adding mozilla/UTN_DATACorp_SGC_Root_CA.crt error adding mozilla/UTN_USERFirst_Email_Root_CA.crt error adding mozilla/UTN_USERFirst_Hardware_Root_CA.crt error adding mozilla/ValiCert_Class_1_VA.crt error adding mozilla/ValiCert_Class_2_VA.crt error adding mozilla/VeriSign_Class_3_Public_Primary_Certification_Authority_-_G5.crt error adding mozilla/Verisign_Class_1_Public_Primary_Certification_Authority.crt error adding mozilla/Verisign_Class_1_Public_Primary_Certification_Authority_-_G2.crt error adding mozilla/Verisign_Class_1_Public_Primary_Certification_Authority_-_G3.crt error adding mozilla/Verisign_Class_2_Public_Primary_Certification_Authority.crt error adding mozilla/Verisign_Class_2_Public_Primary_Certification_Authority_-_G2.crt error adding mozilla/Verisign_Class_2_Public_Primary_Certification_Authority_-_G3.crt error adding mozilla/Verisign_Class_3_Public_Primary_Certification_Authority.crt error adding mozilla/Verisign_Class_3_Public_Primary_Certification_Authority_-_G2.crt error adding mozilla/Verisign_Class_3_Public_Primary_Certification_Authority_-_G3.crt error adding mozilla/Verisign_Class_4_Public_Primary_Certification_Authority_-_G2.crt error adding mozilla/Verisign_Class_4_Public_Primary_Certification_Authority_-_G3.crt error adding mozilla/Verisign_RSA_Secure_Server_CA.crt error adding mozilla/Verisign_Time_Stamping_Authority_CA.crt error adding mozilla/Visa_International_Global_Root_2.crt error adding mozilla/Visa_eCommerce_Root.crt error adding mozilla/WellsSecure_Public_Root_Certificate_Authority.crt error adding mozilla/Wells_Fargo_Root_CA.crt error adding mozilla/XRamp_Global_CA_Root.crt error adding mozilla/beTRUSTed_Root_CA-Baltimore_Implementation.crt error adding mozilla/beTRUSTed_Root_CA.crt error adding mozilla/beTRUSTed_Root_CA_-_Entrust_Implementation.crt error adding mozilla/beTRUSTed_Root_CA_-_RSA_Implementation.crt error adding mozilla/thawte_Primary_Root_CA.crt error adding signet.pl/signet_ca1_pem.crt error adding signet.pl/signet_ca2_pem.crt error adding signet.pl/signet_ca3_pem.crt error adding signet.pl/signet_ocspklasa2_pem.crt error adding signet.pl/signet_ocspklasa3_pem.crt error adding signet.pl/signet_pca2_pem.crt error adding signet.pl/signet_pca3_pem.crt error adding signet.pl/signet_rootca_pem.crt error adding signet.pl/signet_tsa1_pem.crt error adding spi-inc.org/spi-ca-2003.crt error adding spi-inc.org/spi-cacert-2008.crt error adding telesec.de/deutsche-telekom-root-ca-2.crt failed (VM used: java-6-openjdk). dpkg: error processing ca-certificates-java (--configure): subprocess installed post-installation script returned error exit status 1 Errors were encountered while processing: ca-certificates-java E: Sub-process /usr/bin/dpkg returned an error code (1)

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  • "bad record MAC" SSL error between Java and PortgreSQL

    - by Stéphane Bagnier
    Hello there ! We've got here a problem of random disconnections between our Java apps and our PostgreSQL 8.3 server with a "bad record MAC" SSL error. We run Debian / Lenny on both side. On the client side, we see : 2010-03-09 02:36:27,980 WARN org.hibernate.util.JDBCExceptionReporter.logExceptions(JDBCExceptionReporter.java:100) - SQL Error: 0, SQLState: 08006 2010-03-09 02:36:27,980 ERROR org.hibernate.util.JDBCExceptionReporter.logExceptions(JDBCExceptionReporter.java:101) - An I/O error occured while sending to the backend. 2010-03-09 02:36:27,981 ERROR org.hibernate.transaction.JDBCTransaction.toggleAutoCommit(JDBCTransaction.java:232) - Could not toggle autocommit org.postgresql.util.PSQLException: An I/O error occured while sending to the backend. at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:220) at org.postgresql.jdbc2.AbstractJdbc2Connection.executeTransactionCommand(AbstractJdbc2Connection.java:650) at org.postgresql.jdbc2.AbstractJdbc2Connection.commit(AbstractJdbc2Connection.java:670) at org.postgresql.jdbc2.AbstractJdbc2Connection.setAutoCommit(AbstractJdbc2Connection.java:633) at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:597) at org.springframework.jdbc.datasource.SingleConnectionDataSource$CloseSuppressingInvocationHandler.invoke(SingleConnectionDataSource.java:336) at $Proxy17.setAutoCommit(Unknown Source) at org.hibernate.transaction.JDBCTransaction.toggleAutoCommit(JDBCTransaction.java:228) at org.hibernate.transaction.JDBCTransaction.rollbackAndResetAutoCommit(JDBCTransaction.java:220) at org.hibernate.transaction.JDBCTransaction.rollback(JDBCTransaction.java:196) at org.hibernate.ejb.TransactionImpl.rollback(TransactionImpl.java:85) at org.springframework.orm.jpa.JpaTransactionManager.doRollback(JpaTransactionManager.java:482) at org.springframework.transaction.support.AbstractPlatformTransactionManager.processRollback(AbstractPlatformTransactionManager.java:823) at org.springframework.transaction.support.AbstractPlatformTransactionManager.rollback(AbstractPlatformTransactionManager.java:800) at org.springframework.transaction.interceptor.TransactionAspectSupport.completeTransactionAfterThrowing(TransactionAspectSupport.java:339) at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:110) at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:171) at org.springframework.aop.framework.Cglib2AopProxy$DynamicAdvisedInterceptor.intercept(Cglib2AopProxy.java:635) ... Caused by: javax.net.ssl.SSLException: Connection has been shutdown: javax.net.ssl.SSLException: bad record MAC at com.sun.net.ssl.internal.ssl.SSLSocketImpl.checkEOF(SSLSocketImpl.java:1255) at com.sun.net.ssl.internal.ssl.SSLSocketImpl.checkWrite(SSLSocketImpl.java:1267) at com.sun.net.ssl.internal.ssl.AppOutputStream.write(AppOutputStream.java:43) at java.io.BufferedOutputStream.flushBuffer(BufferedOutputStream.java:65) at java.io.BufferedOutputStream.flush(BufferedOutputStream.java:123) at org.postgresql.core.PGStream.flush(PGStream.java:508) at org.postgresql.core.v3.QueryExecutorImpl.sendSync(QueryExecutorImpl.java:692) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:193) ... 22 more Caused by: javax.net.ssl.SSLException: bad record MAC at com.sun.net.ssl.internal.ssl.Alerts.getSSLException(Alerts.java:190) at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1611) at com.sun.net.ssl.internal.ssl.SSLSocketImpl.fatal(SSLSocketImpl.java:1569) at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:850) at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readDataRecord(SSLSocketImpl.java:746) at com.sun.net.ssl.internal.ssl.AppInputStream.read(AppInputStream.java:75) at org.postgresql.core.VisibleBufferedInputStream.readMore(VisibleBufferedInputStream.java:135) at org.postgresql.core.VisibleBufferedInputStream.ensureBytes(VisibleBufferedInputStream.java:104) at org.postgresql.core.VisibleBufferedInputStream.read(VisibleBufferedInputStream.java:186) at org.postgresql.core.PGStream.Receive(PGStream.java:445) at org.postgresql.core.PGStream.ReceiveTupleV3(PGStream.java:350) at org.postgresql.core.v3.QueryExecutorImpl.processResults(QueryExecutorImpl.java:1322) at org.postgresql.core.v3.QueryExecutorImpl.execute(QueryExecutorImpl.java:194) at org.postgresql.jdbc2.AbstractJdbc2Statement.execute(AbstractJdbc2Statement.java:451) at org.postgresql.jdbc2.AbstractJdbc2Statement.executeWithFlags(AbstractJdbc2Statement.java:350) at org.postgresql.jdbc2.AbstractJdbc2Statement.executeQuery(AbstractJdbc2Statement.java:254) at org.hibernate.jdbc.AbstractBatcher.getResultSet(AbstractBatcher.java:208) at org.hibernate.loader.Loader.getResultSet(Loader.java:1808) at org.hibernate.loader.Loader.doQuery(Loader.java:697) at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:259) at org.hibernate.loader.Loader.loadCollection(Loader.java:2015) at org.hibernate.loader.collection.CollectionLoader.initialize(CollectionLoader.java:59) at org.hibernate.persister.collection.AbstractCollectionPersister.initialize(AbstractCollectionPersister.java:587) at org.hibernate.event.def.DefaultInitializeCollectionEventListener.onInitializeCollection(DefaultInitializeCollectionEventListener.java:83) at org.hibernate.impl.SessionImpl.initializeCollection(SessionImpl.java:1743) at org.hibernate.collection.AbstractPersistentCollection.initialize(AbstractPersistentCollection.java:366) at org.hibernate.collection.PersistentSet.add(PersistentSet.java:212) ... the cypher suite SSL_RSA_WITH_RC4_128_SHA was used. We tried on the client side : the OpenJDK package the sun JDK package the sun tar package the libbcprov-java package the PostgreSQL driver 8.3 instead of 8.4 On the server side we see : 2010-03-01 08:26:05 CET [18513]: [161833-1] LOG: SSL error: sslv3 alert bad record mac 2010-03-01 08:26:05 CET [18513]: [161834-1] LOG: could not receive data from client: Connection reset by peer 2010-03-01 08:26:05 CET [18513]: [161835-1] LOG: unexpected EOF on client connection the error type seams to be SSL_R_SSLV3_ALERT_BAD_RECORD_MAC. the SSL layer is configured with : ssl_ciphers = 'ALL:!ADH:!LOW:!EXP:!MD5:@STRENGTH' and on the server side we changed the cipher suites to : 'ALL:!SSLv2:!MEDIUM:!AES:!ADH:!LOW:!EXP:!MD5:@STRENGTH' but none of these changes fixed the problem. Suggestions appreciated !

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  • The Java Specialist: An Interview with Java Champion Heinz Kabutz

    - by Janice J. Heiss
    Dr. Heinz Kabutz is well known for his Java Specialists’ Newsletter, initiated in November 2000, where he displays his acute grasp of the intricacies of the Java platform for an estimated 70,000 readers; for his work as a consultant; and for his workshops and trainings at his home on the Island of Crete where he has lived since 2006 -- where he is known to curl up on the beach with his laptop to hack away, in between dips in the Mediterranean. Kabutz was born of German parents and raised in Cape Town, South Africa, where he developed a love of programming in junior high school through his explorations on a ZX Spectrum computer. He received a B.S. from the University of Cape Town, and at 25, a Ph.D., both in computer science. He will be leading a two-hour hands-on lab session, HOL6500 – “Finding and Solving Java Deadlocks,” at this year’s JavaOne that will explore what causes deadlocks and how to solve them. Q: Tell us about your JavaOne plans.A: I am arriving on Sunday evening and have just one hands-on-lab to do on Monday morning. This is the first time that a non-Oracle team is doing a HOL at JavaOne under Oracle's stewardship and we are all a bit nervous about how it will turn out. Oracle has been immensely helpful in getting us set up. I have a great team helping me: Kirk Pepperdine, Dario Laverde, Benjamin Evans and Martijn Verburg from jClarity, Nathan Reynolds from Oracle, Henri Tremblay of OCTO Technology and Jeff Genender of Savoir Technologies. Monday will be hard work, but after that, I will hopefully get to network with fellow Java experts, attend interesting sessions and just enjoy San Francisco. Oh, and my kids have already given me a shopping list of things to get, like a GoPro Hero 2 dive housing for shooting those nice videos of Crete. (That's me at the beginning diving down.) Q: What sessions are you attending that we should know about?A: Sometimes the most unusual sessions are the best. I avoid the "big names". They often are spread too thin with all their sessions, which makes it difficult for them to deliver what I would consider deep content. I also avoid entertainers who might be good at presenting but who do not say that much.In 2010, I attended a session by Vladimir Yaroslavskiy where he talked about sorting. Although he struggled to speak English, what he had to say was spectacular. There was hardly anybody in the room, having not heard of Vladimir before. To me that was the highlight of 2010. Funnily enough, he was supposed to speak with Joshua Bloch, but if you remember, Google cancelled. If Bloch has been there, the room would have been packed to capacity.Q: Give us an update on the Java Specialists’ Newsletter.A: The Java Specialists' Newsletter continues being read by an elite audience around the world. The apostrophe in the name is significant.  It is a newsletter for Java specialists. When I started it twelve years ago, I was trying to find non-obvious things in Java to write about. Things that would be interesting to an advanced audience.As an April Fool's joke, I told my readers in Issue 44 that subscribing would remain free, but that they would have to pay US$5 to US$7 depending on their geographical location. I received quite a few angry emails from that one. I would have not earned that much from unsubscriptions. Most readers stay for a very long time.After Oracle bought Sun, the Java community held its breath for about two years whilst Oracle was figuring out what to do with Java. For a while, we were quite concerned that there was not much progress shown by Oracle. My newsletter still continued, but it was quite difficult finding new things to write about. We have probably about 70,000 readers, which is quite a small number for a Java publication. However, our readers are the top in the Java industry. So I don't mind having "only" 70000 readers, as long as they are the top 0.7%.Java concurrency is a very important topic that programmers think they should know about, but often neglect to fully understand. I continued writing about that and made some interesting discoveries. For example, in Issue 165, I showed how we can get thread starvation with the ReadWriteLock. This was a bug in Java 5, which was corrected in Java 6, but perhaps a bit too much. Whereas we could get starvation of writers in Java 5, in Java 6 we could now get starvation of readers. All of these interesting findings make their way into my courseware to help companies avoid these pitfalls.Another interesting discovery was how polymorphism works in the Server HotSpot compiler in Issue 157 and Issue 158. HotSpot can inline methods from interfaces that have only one implementation class in the JVM. When a new subclass is instantiated and called for the first time, the JVM will undo the previous optimization and re-optimize differently.Here is a little memory puzzle for your readers: public class JavaMemoryPuzzle {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzle jmp = new JavaMemoryPuzzle();    jmp.f();  }}When you run this you will always get an OutOfMemoryError, even though the local variable data is no longer visible outside of the code block.So here comes the puzzle, that I'd like you to ponder a bit. If you very politely ask the VM to release memory, then you don't get an OutOfMemoryError: public class JavaMemoryPuzzlePolite {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    for(int i=0; i<10; i++) {      System.out.println("Please be so kind and release memory");    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzlePolite jmp = new JavaMemoryPuzzlePolite();    jmp.f();    System.out.println("No OutOfMemoryError");  }}Why does this work? When I published this in my newsletter, I received over 400 emails from excited readers around the world, most of whom sent me the wrong explanation. After the 300th wrong answer, my replies became unfortunately a bit curt. Have a look at Issue 174 for a detailed explanation, but before you do, put on your thinking caps and try to figure it out yourself. Q: What do you think Java developers should know that they currently do not know?A: They should definitely get to know more about concurrency. It is a tough subject that most programmers try to avoid. Unfortunately we do come in contact with it. And when we do, we need to know how to protect ourselves and how to solve tricky system errors.Knowing your IDE is also useful. Most IDEs have a ton of shortcuts, which can make you a lot more productive in moving code around. Another thing that is useful is being able to read GC logs. Kirk Pepperdine has a great talk at JavaOne that I can recommend if you want to learn more. It's this: CON5405 – “Are Your Garbage Collection Logs Speaking to You?” Q: What are you looking forward to in Java 8?A: I'm quite excited about lambdas, though I must confess that I have not studied them in detail yet. Maurice Naftalin's Lambda FAQ is quite a good start to document what you can do with them. I'm looking forward to finding all the interesting bugs that we will now get due to lambdas obscuring what is really going on underneath, just like we had with generics.I am quite impressed with what the team at Oracle did with OpenJDK's performance. A lot of the benchmarks now run faster.Hopefully Java 8 will come with JSR 310, the Date and Time API. It still boggles my mind that such an important API has been left out in the cold for so long.What I am not looking forward to is losing perm space. Even though some systems run out of perm space, at least the problem is contained and they usually manage to work around it. In most cases, this is due to a memory leak in that region of memory. Once they bundle perm space with the old generation, I predict that memory leaks in perm space will be harder to find. More contracts for us, but also more pain for our customers. Originally published on blogs.oracle.com/javaone.

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  • The Java Specialist: An Interview with Java Champion Heinz Kabutz

    - by Janice J. Heiss
    Dr. Heinz Kabutz is well known for his Java Specialists’ Newsletter, initiated in November 2000, where he displays his acute grasp of the intricacies of the Java platform for an estimated 70,000 readers; for his work as a consultant; and for his workshops and trainings at his home on the Island of Crete where he has lived since 2006 -- where he is known to curl up on the beach with his laptop to hack away, in between dips in the Mediterranean. Kabutz was born of German parents and raised in Cape Town, South Africa, where he developed a love of programming in junior high school through his explorations on a ZX Spectrum computer. He received a B.S. from the University of Cape Town, and at 25, a Ph.D., both in computer science. He will be leading a two-hour hands-on lab session, HOL6500 – “Finding and Solving Java Deadlocks,” at this year’s JavaOne that will explore what causes deadlocks and how to solve them. Q: Tell us about your JavaOne plans.A: I am arriving on Sunday evening and have just one hands-on-lab to do on Monday morning. This is the first time that a non-Oracle team is doing a HOL at JavaOne under Oracle's stewardship and we are all a bit nervous about how it will turn out. Oracle has been immensely helpful in getting us set up. I have a great team helping me: Kirk Pepperdine, Dario Laverde, Benjamin Evans and Martijn Verburg from jClarity, Nathan Reynolds from Oracle, Henri Tremblay of OCTO Technology and Jeff Genender of Savoir Technologies. Monday will be hard work, but after that, I will hopefully get to network with fellow Java experts, attend interesting sessions and just enjoy San Francisco. Oh, and my kids have already given me a shopping list of things to get, like a GoPro Hero 2 dive housing for shooting those nice videos of Crete. (That's me at the beginning diving down.) Q: What sessions are you attending that we should know about?A: Sometimes the most unusual sessions are the best. I avoid the "big names". They often are spread too thin with all their sessions, which makes it difficult for them to deliver what I would consider deep content. I also avoid entertainers who might be good at presenting but who do not say that much.In 2010, I attended a session by Vladimir Yaroslavskiy where he talked about sorting. Although he struggled to speak English, what he had to say was spectacular. There was hardly anybody in the room, having not heard of Vladimir before. To me that was the highlight of 2010. Funnily enough, he was supposed to speak with Joshua Bloch, but if you remember, Google cancelled. If Bloch has been there, the room would have been packed to capacity.Q: Give us an update on the Java Specialists’ Newsletter.A: The Java Specialists' Newsletter continues being read by an elite audience around the world. The apostrophe in the name is significant.  It is a newsletter for Java specialists. When I started it twelve years ago, I was trying to find non-obvious things in Java to write about. Things that would be interesting to an advanced audience.As an April Fool's joke, I told my readers in Issue 44 that subscribing would remain free, but that they would have to pay US$5 to US$7 depending on their geographical location. I received quite a few angry emails from that one. I would have not earned that much from unsubscriptions. Most readers stay for a very long time.After Oracle bought Sun, the Java community held its breath for about two years whilst Oracle was figuring out what to do with Java. For a while, we were quite concerned that there was not much progress shown by Oracle. My newsletter still continued, but it was quite difficult finding new things to write about. We have probably about 70,000 readers, which is quite a small number for a Java publication. However, our readers are the top in the Java industry. So I don't mind having "only" 70000 readers, as long as they are the top 0.7%.Java concurrency is a very important topic that programmers think they should know about, but often neglect to fully understand. I continued writing about that and made some interesting discoveries. For example, in Issue 165, I showed how we can get thread starvation with the ReadWriteLock. This was a bug in Java 5, which was corrected in Java 6, but perhaps a bit too much. Whereas we could get starvation of writers in Java 5, in Java 6 we could now get starvation of readers. All of these interesting findings make their way into my courseware to help companies avoid these pitfalls.Another interesting discovery was how polymorphism works in the Server HotSpot compiler in Issue 157 and Issue 158. HotSpot can inline methods from interfaces that have only one implementation class in the JVM. When a new subclass is instantiated and called for the first time, the JVM will undo the previous optimization and re-optimize differently.Here is a little memory puzzle for your readers: public class JavaMemoryPuzzle {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzle jmp = new JavaMemoryPuzzle();    jmp.f();  }}When you run this you will always get an OutOfMemoryError, even though the local variable data is no longer visible outside of the code block.So here comes the puzzle, that I'd like you to ponder a bit. If you very politely ask the VM to release memory, then you don't get an OutOfMemoryError: public class JavaMemoryPuzzlePolite {  private final int dataSize =      (int) (Runtime.getRuntime().maxMemory() * 0.6);  public void f() {    {      byte[] data = new byte[dataSize];    }    for(int i=0; i<10; i++) {      System.out.println("Please be so kind and release memory");    }    byte[] data2 = new byte[dataSize];  }  public static void main(String[] args) {    JavaMemoryPuzzlePolite jmp = new JavaMemoryPuzzlePolite();    jmp.f();    System.out.println("No OutOfMemoryError");  }}Why does this work? When I published this in my newsletter, I received over 400 emails from excited readers around the world, most of whom sent me the wrong explanation. After the 300th wrong answer, my replies became unfortunately a bit curt. Have a look at Issue 174 for a detailed explanation, but before you do, put on your thinking caps and try to figure it out yourself. Q: What do you think Java developers should know that they currently do not know?A: They should definitely get to know more about concurrency. It is a tough subject that most programmers try to avoid. Unfortunately we do come in contact with it. And when we do, we need to know how to protect ourselves and how to solve tricky system errors.Knowing your IDE is also useful. Most IDEs have a ton of shortcuts, which can make you a lot more productive in moving code around. Another thing that is useful is being able to read GC logs. Kirk Pepperdine has a great talk at JavaOne that I can recommend if you want to learn more. It's this: CON5405 – “Are Your Garbage Collection Logs Speaking to You?” Q: What are you looking forward to in Java 8?A: I'm quite excited about lambdas, though I must confess that I have not studied them in detail yet. Maurice Naftalin's Lambda FAQ is quite a good start to document what you can do with them. I'm looking forward to finding all the interesting bugs that we will now get due to lambdas obscuring what is really going on underneath, just like we had with generics.I am quite impressed with what the team at Oracle did with OpenJDK's performance. A lot of the benchmarks now run faster.Hopefully Java 8 will come with JSR 310, the Date and Time API. It still boggles my mind that such an important API has been left out in the cold for so long.What I am not looking forward to is losing perm space. Even though some systems run out of perm space, at least the problem is contained and they usually manage to work around it. In most cases, this is due to a memory leak in that region of memory. Once they bundle perm space with the old generation, I predict that memory leaks in perm space will be harder to find. More contracts for us, but also more pain for our customers.

    Read the article

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