Search Results

Search found 70043 results on 2802 pages for 'java lang class'.

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

Page 225/2802 | < Previous Page | 221 222 223 224 225 226 227 228 229 230 231 232  | Next Page >

  • a way to use log4j pass values like java -DmyEnvVar=A_VALUE to my code

    - by raticulin
    I need to pass some value to enable certain code in may app (in this case is to optionally enable writing some stats to a file in certain conditions, but it might be anything generally). My java app is installed as a service. So every way I have thought of has some drawbacks: Add another param to main(): cumbersome as customers already have the tool installed, and the command line would need to be changed every time. Adding java -DmyEnvVar=A_VALUE to my command line: same as above. Set an environment variable: service should at least be restarted, and even then you must take care of what user is the service running under etc. Adding the property in the config file: I prefer not to have this visible on the config file so the user does not see it, it is something for debugging etc. So I thought maybe there is some way (or hack) to use log4j loggers to pass that value to my code. I have thought of one way already, although is very limited: Add a dummy class to my codebase com.dummy.DevOptions public class DevOptions { public static final Logger logger = Logger.getLogger(DevOptions.class); In my code, use it like this: if (DevOptions.logger.isInfoEnabled()){ //do my optional stuff } //... if (DevOptions.logger.isDebugEnabled()){ //do other stuff } This allows me to use discriminate among various values, and I could increase the number by adding more loggers to DevOptions. But I wonder whether there is a cleaner way, possibly by configuring the loggers only in log4j.xml??

    Read the article

  • Java Detect Variable Change Using PropertyChangeSupport and PropertyChangeListener

    - by Sam
    I'm trying to print out debug statements when some third party code changes a variable. For example, consider the following: public final class MysteryClass { private int secretCounter; public synchronized int getCounter() { return secretCounter; } public synchronized void incrementCounter() { secretCounter++; } } public class MyClass { public static void main(String[] args) { MysteryClass mysteryClass = new MysteryClass(); // add code here to detect calls to incrementCounter and print a debug message } I don't have the ability to change the 3rd party MysteryClass, so I thought that I could use PropertyChangeSupport and PropertyChangeListener to detect changes to the secretCounter: public class MyClass implements PropertyChangeListener { private PropertyChangeSupport propertySupport = new PropertyChangeSupport(this); public MyClass() { propertySupport.addPropertyChangeListener(this); } public void propertyChange(PropertyChangeEvent evt) { System.out.println("property changing: " + evt.getPropertyName()); } public static void main(String[] args) { MysteryClass mysteryClass = new MysteryClass(); // do logic which involves increment and getting the value of MysteryClass } } Unfortunately, this did not work and I have no debug messages printed out. Does anyone see what is wrong with my implementation of the PropertyChangeSupport and Listener interfaces? I want to print a debug statement whenever incrementCounter is called or the value of secretCounter changes.

    Read the article

  • java: assigning object reference IDs for custom serialization

    - by Jason S
    For various reasons I have a custom serialization where I am dumping some fairly simple objects to a data file. There are maybe 5-10 classes, and the object graphs that result are acyclic and pretty simple (each serialized object has 1 or 2 references to another that are serialized). For example: class Foo { final private long id; public Foo(long id, /* other stuff */) { ... } } class Bar { final private long id; final private Foo foo; public Bar(long id, Foo foo, /* other stuff */) { ... } } class Baz { final private long id; final private List<Bar> barList; public Baz(long id, List<Bar> barList, /* other stuff */) { ... } } The id field is just for the serialization, so that when I am serializing to a file, I can write objects by keeping a record of which IDs have been serialized so far, then for each object checking whether its child objects have been serialized and writing the ones that haven't, finally writing the object itself by writing its data fields and the IDs corresponding to its child objects. What's puzzling me is how to assign id's. I thought about it, and it seems like there are three cases for assigning an ID: dynamically-created objects -- id is assigned from a counter that increments reading objects from disk -- id is assigned from the number stored in the disk file singleton objects -- object is created prior to any dynamically-created object, to represent a singleton object that is always present. How can I handle these properly? I feel like I'm reinventing the wheel and there must be a well-established technique for handling all the cases.

    Read the article

  • Java: How ArrayList memory management

    - by cka3o4nik
    In my Data Structures class we have studies the Java ArrayList class, and how it grows the underlying array when a user adds more elements. That is understood. However, I cannot figure out how exactly this class frees up memory when lots of elements are removed from the list. Looking at the source, there are three methods that remove elements: [code] public E remove(int index) { RangeCheck(index); modCount++; E oldValue = (E) elementData[index]; int numMoved = size - index - 1; if (numMoved 0) System.arraycopy(elementData, index+1, elementData, index, numMoved); elementData[--size] = null; // Let gc do its work return oldValue; } public boolean remove(Object o) { if (o == null) { for (int index = 0; index < size; index++) if (elementData[index] == null) { fastRemove(index); return true; } } else { for (int index = 0; index < size; index++) if (o.equals(elementData[index])) { fastRemove(index); return true; } } return false; } private void fastRemove(int index) { modCount++; int numMoved = size - index - 1; if (numMoved 0) System.arraycopy(elementData, index+1, elementData, index, numMoved); elementData[--size] = null; // Let gc do its work } {/code] None of them reduce the datastore array. I even started questioning if memory free up ever happens, but empirical tests show that it does. So there must be some other way it is done, but where and how? I checked the parent classes as well with no success.

    Read the article

  • java threads don't see shared boolean changes

    - by andymur
    Here the code class Aux implements Runnable { private Boolean isOn = false; private String statusMessage; private final Object lock; public Aux(String message, Object lock) { this.lock = lock; this.statusMessage = message; } @Override public void run() { for (;;) { synchronized (lock) { if (isOn && "left".equals(this.statusMessage)) { isOn = false; System.out.println(statusMessage); } else if (!isOn && "right".equals(this.statusMessage)) { isOn = true; System.out.println(statusMessage); } if ("left".equals(this.statusMessage)) { System.out.println("left " + isOn); } } } } } public class Question { public static void main(String [] args) { Object lock = new Object(); new Thread(new Aux("left", lock)).start(); new Thread(new Aux("right", lock)).start(); } } In this code I expect to see: left, right, left right and so on, but when Thread with "left" message changes isOn to false, Thread with "right" message don't see it and I get ("right true" and "left false" console messages), left thread don't get isOn in true, but right Thread can't change it cause it always see old isOn value (true). When i add volatile modifier to isOn nothing changes, but if I change isOn to some class with boolean field and change this field then threads are see changes and it works fine Thanks in advance.

    Read the article

  • Combining HBase and HDFS results in Exception in makeDirOnFileSystem

    - by utrecht
    Introduction An attempt to combine HBase and HDFS results in the following: 2014-06-09 00:15:14,777 WARN org.apache.hadoop.hbase.HBaseFileSystem: Create Dir ectory, retries exhausted 2014-06-09 00:15:14,780 FATAL org.apache.hadoop.hbase.master.HMaster: Unhandled exception. Starting shutdown. java.io.IOException: Exception in makeDirOnFileSystem at org.apache.hadoop.hbase.HBaseFileSystem.makeDirOnFileSystem(HBaseFile System.java:136) at org.apache.hadoop.hbase.master.MasterFileSystem.checkRootDir(MasterFi leSystem.java:428) at org.apache.hadoop.hbase.master.MasterFileSystem.createInitialFileSyst emLayout(MasterFileSystem.java:148) at org.apache.hadoop.hbase.master.MasterFileSystem.<init>(MasterFileSyst em.java:133) at org.apache.hadoop.hbase.master.HMaster.finishInitialization(HMaster.j ava:572) at org.apache.hadoop.hbase.master.HMaster.run(HMaster.java:432) at java.lang.Thread.run(Thread.java:744) Caused by: org.apache.hadoop.security.AccessControlException: Permission denied: user=hbase, access=WRITE, inode="/":vagrant:supergroup:drwxr-xr-x at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPe rmissionChecker.java:224) at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.check(FSPe rmissionChecker.java:204) at org.apache.hadoop.hdfs.server.namenode.FSPermissionChecker.checkPermi ssion(FSPermissionChecker.java:149) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkPermission(F SNamesystem.java:4891) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkPermission(F SNamesystem.java:4873) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.checkAncestorAcce ss(FSNamesystem.java:4847) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInternal(FS Namesystem.java:3192) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirsInt(FSNames ystem.java:3156) at org.apache.hadoop.hdfs.server.namenode.FSNamesystem.mkdirs(FSNamesyst em.java:3137) at org.apache.hadoop.hdfs.server.namenode.NameNodeRpcServer.mkdirs(NameN odeRpcServer.java:669) at org.apache.hadoop.hdfs.protocolPB.ClientNamenodeProtocolServerSideTra nslatorPB.mkdirs(ClientNamenodeProtocolServerSideTranslatorPB.java:419) at org.apache.hadoop.hdfs.protocol.proto.ClientNamenodeProtocolProtos$Cl ientNamenodeProtocol$2.callBlockingMethod(ClientNamenodeProtocolProtos.java:4497 0) at org.apache.hadoop.ipc.ProtobufRpcEngine$Server$ProtoBufRpcInvoker.cal l(ProtobufRpcEngine.java:453) at org.apache.hadoop.ipc.RPC$Server.call(RPC.java:1002) at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1752) at org.apache.hadoop.ipc.Server$Handler$1.run(Server.java:1748) at java.security.AccessController.doPrivileged(Native Method) at javax.security.auth.Subject.doAs(Subject.java:422) at org.apache.hadoop.security.UserGroupInformation.doAs(UserGroupInforma tion.java:1438) at org.apache.hadoop.ipc.Server$Handler.run(Server.java:1746) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstruct orAccessorImpl.java:62) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingC onstructorAccessorImpl.java:45) at java.lang.reflect.Constructor.newInstance(Constructor.java:408) at org.apache.hadoop.ipc.RemoteException.instantiateException(RemoteExce ption.java:90) at org.apache.hadoop.ipc.RemoteException.unwrapRemoteException(RemoteExc eption.java:57) at org.apache.hadoop.hdfs.DFSClient.primitiveMkdir(DFSClient.java:2153) at org.apache.hadoop.hdfs.DFSClient.mkdirs(DFSClient.java:2122) at org.apache.hadoop.hdfs.DistributedFileSystem.mkdirs(DistributedFileSy stem.java:545) at org.apache.hadoop.fs.FileSystem.mkdirs(FileSystem.java:1915) at org.apache.hadoop.hbase.HBaseFileSystem.makeDirOnFileSystem(HBaseFile System.java:129) ... 6 more while configuration and system settings are as follows: [vagrant@localhost hadoop-hdfs]$ hadoop fs -ls hdfs://localhost/ Found 1 items -rw-r--r-- 3 vagrant supergroup 1010827264 2014-06-08 19:01 hdfs://localhost/u buntu-14.04-desktop-amd64.iso [vagrant@localhost hadoop-hdfs]$ /etc/hadoop/conf/core-site.xml <configuration> <property> <name>fs.defaultFS</name> <value>hdfs://localhost:8020</value> </property> </configuration> /etc/hbase/conf/hbase-site.xml <configuration> <property> <name>hbase.rootdir</name> <value>hdfs://localhost:8020/hbase</value> </property> <property> <name>hbase.cluster.distributed</name> <value>true</value> </property> </configuration> /etc/hadoop/conf/hdfs-site.xml <configuration> <property> <name>dfs.name.dir</name> <value>/var/lib/hadoop-hdfs/cache</value> </property> <property> <name>dfs.data.dir</name> <value>/tmp/hellodatanode</value> </property> </configuration> NameNode directory permissions [vagrant@localhost hadoop-hdfs]$ ls -ltr /var/lib/hadoop-hdfs/cache total 8 -rwxrwxrwx. 1 hbase hdfs 15 Jun 8 23:43 in_use.lock drwxrwxrwx. 2 hbase hdfs 4096 Jun 8 23:43 current [vagrant@localhost hadoop-hdfs]$ HMaster is able to start if fs.defaultFS property has been commented in core-site.xml NameNode is listening [vagrant@localhost hadoop-hdfs]$ netstat -nato | grep 50070 tcp 0 0 0.0.0.0:50070 0.0.0.0:* LIST EN off (0.00/0/0) tcp 0 0 33.33.33.33:50070 33.33.33.1:57493 ESTA BLISHED off (0.00/0/0) and accessible by navigating to http://33.33.33.33:50070/dfshealth.jsp. Question How to solve makeDirOnFileSystem exception and let HBase connect to HDFS?

    Read the article

  • What are the ways to start making actual/real-world programs using Java/C++ to excel my Programming Skills?

    - by Umer Hassan
    The programming that we learn at university is not that vast, like those are really small exercises to build our logic, but everyone knows that this will not be the scenario when I'll get out in the market as a professional programmer, I really want to make real life programs which would actual make some impacts and will be useful. Tell me in the light of your experience that how should I start making those programs and polish my self as a professional programmer, if there are any sources available for it then kindly also recommend me those.

    Read the article

  • Gilda Garretón, a Java Developer and Parallelism Computing Researcher

    - by Yolande
    In a new interview titled “Gilda Garretón, a Java Developer and Parallelism Computing Research,” Garretón shares her first-hand experience developing with Java and Java 7 for very large-scale integration (VLSI) of computer-aided design (CAD). Garretón gives an insightful overview of how Java is contributing to the parallelism development and to the Electric VLSI Design Systems, an open source VLSI CAD application used as a research platform for new CAD algorithms as well as the research flow for hardware test chips.  Garretón considers that parallelism programming is hard and complex, yet important developments are taking place.  "With the addition of the concurrent package in Java SE 6 and the Fork/Join feature in Java SE 7, developers have a chance to rely more on existing frameworks and dedicate more time to the essence of their parallel algorithms." Read the full article here  

    Read the article

  • OpenGL: Attempt to allocate a texture to big for the current hardware

    - by AnonymousMan
    I'm getting the following error: java.io.IOException: Attempt to allocate a texture to big for the current hardware at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:320) at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:254) at org.newdawn.slick.opengl.InternalTextureLoader.getTexture(InternalTextureLoader.java:200) at org.newdawn.slick.opengl.TextureLoader.getTexture(TextureLoader.java:64) at org.newdawn.slick.opengl.TextureLoader.getTexture(TextureLoader.java:24) The image I'm trying to use is 128x128. System.out.println(GL11.glGetInteger(GL11.GL_MAX_TEXTURE_SIZE)); I get: 32. 32??!! My graphics card is AMD Radeon HD 7970M with 2048 MB GDDR5 RAM, I can run all the latest games in 1080p and 60fps with no problem, and those textures sure as hell doesn't look like they are 32x32 pixels to me! How can I fix this? -- Edit: Here's the chaos code I use to init OpenGL: Display.setDisplayMode(new DisplayMode(500,500)); Display.create(); if (!GLContext.getCapabilities().OpenGL11) { throw new Exception("OpenGL 1.1 not supported."); } Display.setTitle("Game"); glMatrixMode(GL_PROJECTION); glLoadIdentity(); GLU.gluPerspective(45, 1, 0.1f, 5000); Mouse.setGrabbed(true); glMatrixMode(GL_MODELVIEW); glLoadIdentity(); glEnable(GL_TEXTURE_2D); glClearColor(0, 0, 0, 0); glEnable(GL_DEPTH_TEST); glDepthFunc(GL_LEQUAL); glHint(GL_PERSPECTIVE_CORRECTION_HINT, GL_NICEST); glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); glEnable(GL_BLEND); glEnable(GL_POINT_SMOOTH); glEnable(GL_LINE_SMOOTH); glEnable(GL_POLYGON_SMOOTH); glEnable(GL_POLYGON_OFFSET_FILL); glShadeModel(GL_SMOOTH); Display is a LWJGL thing, it makes the OpenGL context and the window. Anyway, I don't think there's anything in the init code that can help me but you never know...

    Read the article

  • Java 7 Adoption at 79%

    - by Henrik Stahl
    According to a recent blog post from the cloud hosting company Jelastic, Java 7 adoption on their platform is now at 79%. While this is a single data point and should not be read too broadly, it does match other indicators we have that Java 7 is picking up, such as uptake among Oracle middleware customers, download statistics and online activity. The spike in adoption in April coincided with the release of JDK 7 Update 4. This is in line with our expectations since that release added Mac OS X support as well as java.com moving to Java 7 as the default download for end-users; two events that marked the maturity of Java 7 to the community. Since the original release of Java 7, Oracle has shipped 7 update releases, added ports to Mac OSX and Linux/ARM and expanded JavaFX to all common desktop platforms.

    Read the article

  • Is Java viable for serious game development?

    - by tehtros
    Ever since I was a little kid, my dream has been to develop games. Well, now that I am older, more mature, and have some programming experience, I would like to start. However, I would like to turn this into a career. The problem, is that my language of choice is Java. Now, I am not intending this to be a Java vs. C++ question, but rather, is Java an acceptable language for serious game development, instead of lower level languages like C++. By serious, I mean high quality graphics, and being able to play a game with said high quality graphics, without much lag on decent computers. Also, eventually, possible making it to consoles. I have scoured the internet, but there are not very many resources for Java game development, not nearly as many as C++. In fact, most engines are written in C++. Once, I tried to play a made with jMonkeyEngine. The game was terribly slow, to the point where my computer froze. I had no other Java applications running and nothing too resource intensive. Keep in mind, that my computer can play most modern 3D games with ease. So, I am really serious about game development, is Java still a viable choice? I have tried multiple times to learn C++, but I don't really like the language. I don't really know why, but usually, whenever I try to learn, I can never grasp the topics. Also, my most of my friends know Java, and one is even anti-C++, saying that no one knows how to use it right. Then, he goes to say that "there is no right way to use C++, that it can not be used correctly. The nature of the language prevents good code." Also, if I continue to learn and improve Java now, and it turns out that later I am required to learn C++, will making the switch be difficult? So, in short, can Java be taken serious, for serious game development. This includes heavy graphics, fast game play without lag, and possibly, and easy switch to consoles?

    Read the article

  • Devoxx 2011: Java EE 6 Hands-on Lab Delivered

    - by arungupta
    I, along with Alexis's help, delivered a Java EE 6 hands-on lab to a packed room of about 40+ attendees at Devoxx 2011. The lab was derived from the OTN Developer Days 2012 version but added lot more content to showcase several Java EE 6 technologies. The problem statement from the lab document states: This hands-on lab builds a typical 3-tier Java EE 6 Web application that retrieves customer information from a database and displays it in a Web page. The application also allows new customers to be added to the database as well. The string-based and type-safe queries are used to query and add rows to the database. Each row in the database table is published as a RESTful resource and is then accessed programmatically. Typical design patterns required by a Web application like validation, caching, observer, partial page rendering, and cross-cutting concerns like logging are explained and implemented using different Java EE 6 technologies. The lab covered Java Persistence API 2, Servlet 3, Enterprise JavaBeans 3.1, JavaServer Faces 2, Java API for RESTful Web Services 1.1, Contexts and Dependency Injection 1.0, and Bean Validation 1.0 over 47 pages of detailed self-paced instructions. Here is the complete Table of Contents: The lab can be downloaded from here and requires only NetBeans IDE "All" or "Java EE" version, which includes GlassFish anyway. All the feedback received from the lab has been incorporated in the instructions and bugs filed (Updated 49559, 205232, 205248, 205256). 80% of the attendees could easily complete the lab and some even completed in much less than 3 hours. That indicates that either more content needs to be added to the lab or the intellectual level of the attendees at the conference was pretty high. I think the lab has enough content for 3 hours but we moved at a much more faster pace so I conclude on the latter. Truly a joy to conduct a lab to 40 Devoxxians! Another related lab that might be handy for folks is "Develop, Deploy, and Monitor your Java EE 6 applications using GlassFish 3.1 Cluster". It explains how: Create a 2-instance GlassFish cluster Front-end with a Web server and a load balancer Demonstrate session replication and fail over Monitor the application using JavaScript The complete lab instructions and source code are available and you can try them. I plan to continue evolving the contents for the Java EE 6 hands-on lab to cover more technologies and features and will announce them on this blog. Let me know on what else would you like to see in the future versions.

    Read the article

  • Devoxx 2011: Java EE 6 Hands-on Lab Delivered

    - by arungupta
    I, along with Alexis's help, delivered a Java EE 6 hands-on lab to a packed room of about 40+ attendees at Devoxx 2011. The lab was derived from the OTN Developer Days 2012 version but added lot more content to showcase several Java EE 6 technologies. The problem statement from the lab document states: This hands-on lab builds a typical 3-tier Java EE 6 Web application that retrieves customer information from a database and displays it in a Web page. The application also allows new customers to be added to the database as well. The string-based and type-safe queries are used to query and add rows to the database. Each row in the database table is published as a RESTful resource and is then accessed programmatically. Typical design patterns required by a Web application like validation, caching, observer, partial page rendering, and cross-cutting concerns like logging are explained and implemented using different Java EE 6 technologies. The lab covered Java Persistence API 2, Servlet 3, Enterprise JavaBeans 3.1, JavaServer Faces 2, Java API for RESTful Web Services 1.1, Contexts and Dependency Injection 1.0, and Bean Validation 1.0 over 47 pages of detailed self-paced instructions. Here is the complete Table of Contents: The lab can be downloaded from here and requires only NetBeans IDE "All" or "Java EE" version, which includes GlassFish anyway. All the feedback received from the lab has been incorporated in the instructions and bugs filed (Updated 49559, 205232, 205248, 205256). 80% of the attendees could easily complete the lab and some even completed in much less than 3 hours. That indicates that either more content needs to be added to the lab or the intellectual level of the attendees at the conference was pretty high. I think the lab has enough content for 3 hours but we moved at a much more faster pace so I conclude on the latter. Truly a joy to conduct a lab to 40 Devoxxians! Another related lab that might be handy for folks is "Develop, Deploy, and Monitor your Java EE 6 applications using GlassFish 3.1 Cluster". It explains how: Create a 2-instance GlassFish cluster Front-end with a Web server and a load balancer Demonstrate session replication and fail over Monitor the application using JavaScript The complete lab instructions and source code are available and you can try them. I plan to continue evolving the contents for the Java EE 6 hands-on lab to cover more technologies and features and will announce them on this blog. Let me know on what else would you like to see in the future versions.

    Read the article

  • How are Java ByteBuffer's limit and position variable's updated?

    - by Dummy Derp
    There are two scenarios: writing and reading Writing: Whenever I write something to the ByteBuffer by calling its put(byte[]) method the position variable is incremented as: current position + size of byte[] and limit stays at the max. If, however, I put the data in a view buffer then I will have to, manually, calculate and update the position Before I call the write(ByteBuffer) method of the channel to write something, I will have to flip() the Bytebuffer so that position points to zero and limit points to the last byte that was written to the ByteBuffer. Reading: Whenever I call the read(ByteBuffer) method of a channel to read something, the position variable stays at 0 and the limit variable of the ByteBuffer points to the last byte that was read. So, if the ByteBuffer is smaller than the file being read, the limit variable is pushed to max This means that the ByteBuffer is already flipped and I can proceed to extracting the values from the ByteBuffer. Please, correct me where I am wrong :)

    Read the article

  • How I use RegExp in my Java program? [migrated]

    - by MIH1406
    I have the following string examples: 00001 1 12 123 00002 3 7 321 00003 99 23 332 00004 192 50 912 In a separate text file. Numbers are separated by tabs not spaces. I tried to read the file and print each line if it matches a given RegExp, but I could not find the suitable RegExp for these lines. private static void readFile() { String fileName = "processes.lst"; FileReader file = null; String result = ""; try { file = new FileReader(fileName); BufferedReader reader = new BufferedReader(file); String line = null; String regEx = "[0-9]\t[0-9]\t[0-9]\t[0-9]"; while((line = reader.readLine()) != null) { if(line.matches(regEx)) { result += "\n" + line; } } } catch(Exception e) { System.out.println(e.getMessage()); } finally { if(file != null) try { file.close(); } catch(Exception e) { System.out.println(e.getMessage()); } } System.out.println(result); } I ended up without any string being printed!!

    Read the article

  • Which Game Engine to Use for an Angry Bird style game? [JAVA] [on hold]

    - by Arch1tect
    Our team is building an Angry Bird Style game, and we have only about ten days. The game is a little more complex than Angry Bird because there are two players, they each have a castle with pigs to protect(not destroy:)). And the goal is to destroy the other player's pigs. I wonder what Game Engine would help us finish this game most efficiently. We at least need a physics engine but I guess game engine is more helpful since it usually includes physics engine. Correct me if I'm wrong. (So I'm wondering which game engine I should use, if it's just physics engine, I'll use box2d) Networking may or may not be added later depend on time we have. Thanks in advance for any advice! EDIT: image looks small, I'll add one:

    Read the article

  • JavaOne - Java SE Embedded Booth - Servergy Micro Server

    - by David Clack
    Hi All,  So it's been awhile, I've been working with all the ARM and Power Architecture partners we have now on testing Java SE Embedded. We will have a Java SE Embedded for ARM and PPC at Java One next week, I'll be bringing in some of the great ARM and PPC systems to demonstrate.  The first system I'd like to tell you about is a really cool 8 core Power Architecture Micro Server from a company in Dallas called Servergy. Java One will be it's first public outing, Bill Mapp the CEO will be doing a talk at the Java Embedded @ JavaOne conference in the Hotel Nikko, right next door to the JavaOne show in the Hilton. To read more about Servergy https://www.linux.com/news/enterprise/cloud-computing/641488-linux-based-servergy-advances-data-center-efficiency http://www.servergy.com/ If you are registered at JavaOne you can come over to the Java Embedded @ JavaOne for $100 Come see us in booth 5605 See you there Dave

    Read the article

  • Why would Java app make RPC call to itself?

    - by amphibient
    I am working with a multithreaded homegrown multi-module app in my new job. We use the the Thrift protocol to communicate RPC calls between different stand-alone applications in a distributed system. One of them listens on multiple ports and I just noticed that it actually makes an RPC call to itself from one thread invoked from one socket it listens to (web service call) to another port within the same app. I verified that it could accomplish the same thing if it just went and directly called the method that the remote procedure ultimately invokes as it is all within the same application, same JVM. To make it even more mysterious, the call is completely synchronous, i.e. no callbacks involved. The first thread totally sits and waits until it makes a call across the wire to itself and comes back. Now, I am perplexed why anybody would do it this way. It seems like calling somebody on the phone that sits in the same room as you do. Can anybody provide an explanation why the developer before me would come up with the above mentioned model? Maybe there is a reason and I am missing something.

    Read the article

  • How to effectively design a piece of software

    - by ti83plus
    Im a compsci student and ive got some experience in various languages and paradigms c/java/python/ruby/html/css/scheme/sql/asp(classic). I realise that i want to have some software in my portfolio for future job hunting even tho i still have 2 years left of my education. Ive got a pretty good idea of what i want to make, its a webapp. Most shops around here are either .net or java and since i know java best and dont have access to ms developer tools im thinking i should go with java. Even tho i feel i know the principles of OOP pretty good ive got no clue how to go from my idea to a working solution. Where can i access information about designing the underlying architechture of my solution? Also i would like to know what other technologies i should train on, my current list includes javascript(and possibly a javascript library) some sort of java web framework tips are appreciated. I would like to add support for android/iphone apps in the future and this is something i have to take into account when designing the app. I have done a course on software engineering but i found this to be more centered around project management ideas then the actual design and implementation. So i would like tips on technologies i should focus on to get the most out of my time without the massive overhead of huge config processes but at the same time keep my project viable in a business sense, so that i use technologies that are relevant for business (java developer jobs). And i would also like tips on where i can learn more about the design process around a software project, i will be working mostly alone. But i find the approach ive used up until now (start coding and figure it out as you go) wont suffice.

    Read the article

  • Transactional Interceptors in Java EE 7 - Request for feedback

    - by arungupta
    Linda described how EJB's container-managed transactions can be applied to the Java EE 7 platform as a whole using a solution based on CDI interceptors. This can then be used by other Java EE components as well, such as Managed Beans. The plan is to add an annotation and standardized values in the javax.transaction package. For example: @Inherited @InterceptorBinding @Target({TYPE, METHOD}) @Retention(RUNTIME) public @interface Transactional { TxType value() default TxType.REQUIRED } And then this can be specified on a class or a method of a class as: public class ShoppingCart { ... @Transactional public void checkOut() {...} ... } This interceptor will be defined as part of the update to Java Transactions API spec at jta-spec.java.net. The Java EE 7 Expert Group needs your help and looking for feedback on the exact semantics. The complete discussion can be read here. Please post your feedback to users@javaee-spec.java.net and we'll also consider comments posted to this entry.

    Read the article

  • How You Helped Shape Java EE 7...

    - by reza_rahman
    For many of us working with the JCP for years, the commitment to transparency and openness is very clear. For others, perhaps the most visible sign to date of this high regard for grassroots level input is a survey on Java EE 7 gathered a few months ago. The survey was designed to get open feedback on a number of critical issues central to the Java EE 7 umbrella specification including what APIs to include in the standard. The survey was highly successful with a large number of high quality responses. With Java EE 7 under our belt and the horizons for Java EE 8 emerging, this is a good time to thank everyone that took the survey once again for their thoughts and let you know what the impact of your voice actually was. I've posted the details on my personal blog. I hope you are encouraged by how your input to the survey helped shape Java EE 7 and continues to shape Java EE 8. Maybe now is the time for you to get more involved :-)?

    Read the article

  • Can you shade a specific section of a sprite? If so, how? [Java]

    - by l5p4ngl312
    I have been working on an isometric minecraft-esque game engine for a strategy game I plan on making. As you can see, it really needs some sort of shading. It is difficult to distinguish between separate elevations when the camera is facing away from the slope because everything is the same shade. So my question is: can I shade just a specific section of a sprite? All of those blocks are just sprites, so if I shaded the entire image, it would shade the whole block. I am using LWJGL. Heres a link to a screenshot from the engine: http://i44.tinypic.com/qxqlix.jpg

    Read the article

  • Traverse tree with results. Maybe type in Java?

    - by Angelo.Hannes
    I need to check a tree's node state. It can either be OK or NOT_OK. But that state is dependent on its children. So for a node to be OK, every of its children needs to be OK. If one or more of its children is NOT_OK the whole node is NOT_OK. To determine the state of a node I need to aggregate some properties of the node. So I thought of two possible implementations. And they are more or less covered in this question: Why is Option/Maybe considered a good idea and checked exceptions are not? Exception I could pass the properties up the recursion path, and throw an exception if something went wrong. Maybe I implement an Maybe type and let it either hold an error or the aggregated properties. Maybe it is more an Either. I tend towards the last option. And I'm thinking of an enum with two objects. Where I can additionally set those aggregated properties. Am I on the right track? I'm not familiar with the new JDK8 functional stuff. But I'm stuck on JDK7 anyway, so please focus on JDK7.

    Read the article

  • Where can I find a package for "project looking Glass"? ("The Java desktop")

    - by Alvar
    Hi, I really really want to find this package. Because after I saw the youtube clip I realized it's just one of those things I must have done before I die. This tutorial would be great if the repository were online. My question is: Where can I find the file, and how can I install it without changing my current desktop? The project was called "project looking glass" and was released in 2007. It is now an "inactive open source project", according to its Wikipedia article. @Takkat found this VERY good live cd, hope it works.

    Read the article

  • Java Embedded @ JavaOne Toolkit

    - by Tori Wieldt
    Java Embedded @ JavaOne provides business decision makers, technical leaders, and ecosystem partners information about Java Embedded technologies and new business opportunities.  From the enterprise business world to the consumer arena, smart meters, automated buildings, and context-aware medical devices can provide information that drive value for businesses and consumers. Java Embedded @ JavaOne will held Wednesday, Oct. 3th and Thursday, Oct. 4th in San Francisco at the Hotel Nikko (during JavaOne). If you have already registered, you can use the Java Embedded @ JavaOne Toolkit to let people know you are attending, to enhanced your blog, and to generate awareness, enthusiasm, and participation. There are banners and buttons, a list of High-Level Benefits of Attending Java Embbeded @ JavaOne, Sample E-Mail Copy, and more. There is also a Toolkit for Partners, Sponsors and Exhibitors. Check out the Java Embbed @ JavaOne Toolkits!

    Read the article

facebook twitter digg google delicious technorati stumbleupon myspace wordpress linkedin gmail igoogle windows live tumblr viadeo yahoo buzz yahoo mail yahoo bookmarks favorites email print

< Previous Page | 221 222 223 224 225 226 227 228 229 230 231 232  | Next Page >