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  • Tomcat 7 on Ubuntu 12.04 with JRE 7 not starting

    - by Andreas Krueger
    I am running a virtual server in the web on Ubuntu 12.04 LTS / 32 Bit. After a clean install of JRE 7 and Tomcat 7, following the instructions on http://www.sysadminslife.com, I don't get Tomcat 7 up and running. > java -version java version "1.7.0_09" Java(TM) SE Runtime Environment (build 1.7.0_09-b05) Java HotSpot(TM) Client VM (build 23.5-b02, mixed mode) > /etc/init.d/tomcat start Starting Tomcat Using CATALINA_BASE: /usr/local/tomcat Using CATALINA_HOME: /usr/local/tomcat Using CATALINA_TMPDIR: /usr/local/tomcat/temp Using JRE_HOME: /usr/lib/jvm/java-7-oracle Using CLASSPATH: /usr/local/tomcat/bin/bootstrap.jar:/usr/local/tomcat/bin/tomcat-juli.jar > telnet localhost 8080 Trying ::1... Trying 127.0.0.1... telnet: Unable to connect to remote host: Connection refused netstat sometimes shows a Java process, most of the times not. If it does, nothing works either. Does anyone have a solution or encountered similar situations? Here are the contents of catalina.out: 16.11.2012 18:36:39 org.apache.catalina.core.AprLifecycleListener init INFO: The APR based Apache Tomcat Native library which allows optimal performance in production environments was not found on the java.library.path: /usr/lib/jvm/java-6-oracle/lib/i386/client:/usr/lib/jvm/java-6-oracle/lib/i386:/usr/lib/jvm/java-6-oracle/../lib/i386:/usr/java/packages/lib/i386:/lib:/usr/lib 16.11.2012 18:36:40 org.apache.coyote.AbstractProtocol init INFO: Initializing ProtocolHandler ["http-bio-8080"] 16.11.2012 18:36:40 org.apache.coyote.AbstractProtocol init INFO: Initializing ProtocolHandler ["ajp-bio-8009"] 16.11.2012 18:36:40 org.apache.catalina.startup.Catalina load INFO: Initialization processed in 1509 ms 16.11.2012 18:36:40 org.apache.catalina.core.StandardService startInternal INFO: Starting service Catalina 16.11.2012 18:36:40 org.apache.catalina.core.StandardEngine startInternal INFO: Starting Servlet Engine: Apache Tomcat/7.0.29 16.11.2012 18:36:40 org.apache.catalina.startup.HostConfig deployDirectory INFO: Deploying web application directory /usr/local/tomcat/webapps/manager Here come the results of ps -ef, iptables --list and netstat -plut: > ps -ef UID PID PPID C STIME TTY TIME CMD root 1 0 0 Nov16 ? 00:00:00 init root 2 1 0 Nov16 ? 00:00:00 [kthreadd/206616] root 3 2 0 Nov16 ? 00:00:00 [khelper/2066167] root 4 2 0 Nov16 ? 00:00:00 [rpciod/2066167/] root 5 2 0 Nov16 ? 00:00:00 [rpciod/2066167/] root 6 2 0 Nov16 ? 00:00:00 [rpciod/2066167/] root 7 2 0 Nov16 ? 00:00:00 [rpciod/2066167/] root 8 2 0 Nov16 ? 00:00:00 [nfsiod/2066167] root 119 1 0 Nov16 ? 00:00:00 upstart-udev-bridge --daemon root 125 1 0 Nov16 ? 00:00:00 /sbin/udevd --daemon root 157 125 0 Nov16 ? 00:00:00 /sbin/udevd --daemon root 158 125 0 Nov16 ? 00:00:00 /sbin/udevd --daemon root 205 1 0 Nov16 ? 00:00:00 upstart-socket-bridge --daemon root 276 1 0 Nov16 ? 00:00:00 /usr/sbin/sshd -D root 335 1 0 Nov16 ? 00:00:00 /usr/sbin/xinetd -dontfork -pidfile /var/run/xinetd.pid -stayalive -inetd root 348 1 0 Nov16 ? 00:00:00 cron syslog 368 1 0 Nov16 ? 00:00:00 /sbin/syslogd -u syslog root 472 1 0 Nov16 ? 00:00:00 /usr/lib/postfix/master postfix 482 472 0 Nov16 ? 00:00:00 qmgr -l -t fifo -u root 520 1 0 Nov16 ? 00:00:04 /usr/sbin/apache2 -k start www-data 523 520 0 Nov16 ? 00:00:00 /usr/sbin/apache2 -k start www-data 525 520 0 Nov16 ? 00:00:00 /usr/sbin/apache2 -k start www-data 526 520 0 Nov16 ? 00:00:00 /usr/sbin/apache2 -k start tomcat 1074 1 0 Nov16 ? 00:01:08 /usr/lib/jvm/java-6-oracle/bin/java -Djava.util.logging.config.file=/usr/ postfix 1351 472 0 Nov16 ? 00:00:00 tlsmgr -l -t unix -u -c postfix 3413 472 0 17:00 ? 00:00:00 pickup -l -t fifo -u -c root 3457 276 0 17:31 ? 00:00:00 sshd: root@pts/0 root 3459 3457 0 17:31 pts/0 00:00:00 -bash root 3470 3459 0 17:31 pts/0 00:00:00 ps -ef > iptables --list Chain INPUT (policy ACCEPT) target prot opt source destination ACCEPT tcp -- anywhere anywhere tcp dpt:http-alt ACCEPT tcp -- anywhere anywhere tcp dpt:8005 ACCEPT tcp -- anywhere anywhere tcp dpt:http-alt Chain FORWARD (policy ACCEPT) target prot opt source destination Chain OUTPUT (policy ACCEPT) target prot opt source destination > netstat -plut Active Internet connections (only servers) Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name tcp 0 0 *:smtp *:* LISTEN 472/master tcp 0 0 *:3213 *:* LISTEN 276/sshd tcp6 0 0 [::]:smtp [::]:* LISTEN 472/master tcp6 0 0 [::]:8009 [::]:* LISTEN 1074/java tcp6 0 0 [::]:3213 [::]:* LISTEN 276/sshd tcp6 0 0 [::]:http-alt [::]:* LISTEN 1074/java tcp6 0 0 [::]:http [::]:* LISTEN 520/apache2

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  • Maven Integrated View for NetBeans IDE

    - by Geertjan
    Started working on an oft-heard request from Kirk Pepperdine for an integrated view for multimodule builds for Maven projects in NetBeans IDE, as explained here. I suddenly had some kind of brainwave and solved all the remaining problems I had, by delegating to the LogicalViewProvider's node, instead of the project's node, which means I inherit all the icons, actions, package nodes, and anything else that was originally defined within the original project, in this case for the open source JAnnocessor project: Above, you can see that the Maven submodules can either be edited in-line, i.e., within the parent project, or separately, by opening them in the traditional NetBeans way. Get the module here: http://plugins.netbeans.org/plugin/45180/?show=true Some people out there might be interested in how this is achieved. First, hide the original ModulesNodeFactory in the layer. Then create the following class, which creates what you see in the screenshot above: import java.util.ArrayList; import java.util.List; import javax.swing.event.ChangeListener; import org.netbeans.api.project.Project; import org.netbeans.spi.project.SubprojectProvider; import org.netbeans.spi.project.ui.LogicalViewProvider; import org.netbeans.spi.project.ui.support.NodeFactory; import org.netbeans.spi.project.ui.support.NodeList; import org.openide.nodes.FilterNode; import org.openide.nodes.Node; @NodeFactory.Registration(projectType = "org-netbeans-modules-maven", position = 400) public class ModulesNodeFactory2 implements NodeFactory { @Override public NodeList<?> createNodes(Project prjct) { return new MavenModulesNodeList(prjct); } private class MavenModulesNodeList implements NodeList<Project> { private final Project project; public MavenModulesNodeList(Project prjct) { this.project = prjct; } @Override public List<Project> keys() { return new ArrayList<Project>( project.getLookup(). lookup(SubprojectProvider.class).getSubprojects()); } @Override public Node node(final Project project) { Node node = project.getLookup().lookup(LogicalViewProvider.class).createLogicalView(); return new FilterNode(node, new FilterNode.Children(node)); } @Override public void addChangeListener(ChangeListener cl) { } @Override public void removeChangeListener(ChangeListener cl) { } @Override public void addNotify() { } @Override public void removeNotify() { } } } Considering that there's only about 5 actual statements above, it's pretty amazing how much can be achieved with so little code. The NetBeans APIs really are very cool. Hope you like it, Kirk!

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  • How to display a dependent list box disabled if no child data exist

    - by frank.nimphius
    A requirement on OTN was to disable the dependent list box of a model driven list of value configuration whenever the list is empty. To disable the dependent list, the af:selectOneChoice component needs to be refreshed with every value change of the parent list, which however already is the case as the list boxes are already dependent. When you create model driven list of values as choice lists in an ADF Faces page, two ADF list bindings are implicitly created in the PageDef file of the page that hosts the input form. At runtime, a list binding is an instance of FacesCtrlListBinding, which exposes getItems() as a method to access a list of available child data (java.util.List). Using Expression Language, the list is accessible with #{bindings.list_attribute_name.items} To dynamically set the disabled property on the dependent af:selectOneChoice component, however, you need a managed bean that exposes the following two methods //empty – but required – setter method public void setIsEmpty(boolean isEmpty) {} //the method that returns true/false when the list is empty or //has values public boolean isIsEmpty() {   FacesContext fctx = FacesContext.getCurrentInstance();   ELContext elctx = fctx.getELContext();   ExpressionFactory exprFactory =                          fctx.getApplication().getExpressionFactory();   ValueExpression vexpr =                       exprFactory.createValueExpression(elctx,                         "#{bindings.EmployeeId.items}",                       Object.class);   List employeesList = (List) vexpr.getValue(elctx);                        return employeesList.isEmpty()? true : false;      } If referenced from the dependent choice list, as shown below, the list is disabled whenever it contains no list data <! --  master list --> <af:selectOneChoice value="#{bindings.DepartmentId.inputValue}"                                  label="#{bindings.DepartmentId.label}"                                  required="#{bindings.DepartmentId.hints.mandatory}"                                   shortDesc="#{bindings.DepartmentId.hints.tooltip}"                                   id="soc1" autoSubmit="true">      <f:selectItems value="#{bindings.DepartmentId.items}" id="si1"/> </af:selectOneChoice> <! --  dependent  list --> <af:selectOneChoice value="#{bindings.EmployeeId.inputValue}"                                   label="#{bindings.EmployeeId.label}"                                      required="#{bindings.EmployeeId.hints.mandatory}"                                   shortDesc="#{bindings.EmployeeId.hints.tooltip}"                                   id="soc2" disabled="#{lovTestbean.isEmpty}"                                   partialTriggers="soc1">     <f:selectItems value="#{bindings.EmployeeId.items}" id="si2"/> </af:selectOneChoice>

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  • OOW 2012: Kings of Leon & Pearl Jam - Appreciation Event

    - by Mike Dietrich
    June 15, 1992 - that was actually the day when Pearl Jam played their first concert in Serenadenhof in my hometown, Nürnberg. Oups ... that's over 20 years ago ... So I was so happy to get a ticket to this year's OOW 2012 appreciation event on Treasure Island. Every year it amazes me over and over again how the organizers manage it logistically to bring almost 40,000 people to and back from the island. Food was ... I would say fairly ok ... and beer (as always) is not - actually even though I'm not a beer drinker I wouldn't call it beer.  Kings of Leon did start. I like them a lot and owe their 2008 album Only By Night. That was a good start to warm up the crowd. And then Pearl Jam took over - and ... wooooooow ... they are such a great live band. First of all as far as I understood they were donating the money they've got for that gig to an NGO. And Eddie Vedder's voice is simply striking ... I had shivers running down my spine. They played a good excerpt of their +20 years career closing down with Alive at the very end. It seemed to everybody that the band had real fun playing there - and it was sooooo good. Thanks a lot to the person who did organize me a ticket Catching my bus back to my hotel area down at Fisherman's Wharf worked well - but I must have fallen asleep 5 minutes after we've left the parking lot. The next thing I did recognize was the bus driver pushing the breaks at Northpoint. What a wonderful night ...

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  • PHP 5.4 Support: Minor Features

    - by Ondrej Brejla
    Hi all! This weak is another PHP weak. Asking why? PHP migrates to Git and GitHub! Isn't that cool? And this week is also NetBeans for PHP week, because we have some new NetBeans 7.2 features for you. Note: All PHP 5.4 features are available in your projects after setting Project Properties -> Sources -> PHP Version to PHP 5.4 value, or after choosing the same value during a PHP Project creation (in New Project Wizard). Callable type hint Let's start with a new PHP 5.4 type hint - callable. It's now in code completion and you can use it in your function declarations! Binary notation for integers The next feature is about recognizing of a new binary notation for integers, so you can use it without any problem - no syntax error will occur. Class::{expr}() And the last feature is about using of Class::{expr}() invocation. It's supported by our parser too, so no syntax errors will occur either. That's all for today and as usual, please test it and if you find something strange, don't hesitate to file a new issue (component php, subcomponent Editor). Thanks.

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  • JavaOne - Java SE Embedded Booth - Digi - Home Health Hub (HHH)

    - by David Clack
    Hi All,  So another exciting platform we will have in the booth at JavaOne is the Digi  Home Health Hub (HHH) platform. http://www.digi.com/products/wireless-wired-embedded-solutions/single-board-computers/idigi-telehealth-application-kit#overview This is a Freescale reference design that has been built by Digi, the system is powered by a Freescale i.MX28 ARM SOC, what's really exciting me is it has every wireless protocol you could ever want on a single motherboard. Ethernet, 802.11b/g/n Wi-Fi, Bluetooth, ZigBee, configurable Sub-GHz radio, NFC plus USB, audio and LCD/touch screen option. I've been experimenting with lots of wireless capable healthcare products in the last few months, plus some Bluetooth Pulse / Oxy meters, we have been looking at how the actual healthcare wireless protocols work. Steve Popovich - Vice President, Digi Internationalwill be doing a talk at the Java Embedded @ JavaOne conference in the Hotel Nikko, right next door to the JavaOne show in the Hilton. 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

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  • JavaOne 2012 - Java Generics

    - by Sharon Zakhour
    At JavaOne 2012, Venkat Subramaniam of Agile Developer, Inc, presented a conference session titled "The Good, The Bad, and the Ugly of Java Generics." Dr Subramaniam discussed the use of generics, what to watch out for when using generics, and best practices. To learn more about working with generics, see the Generics trail in the Java Tutorials. The trail was recently expanded and coverage added for the following topics: Generics, Inheritance, and Subtypes Guidelines for Wildcard Use Restrictions on Generics Wildcard Capture and Helper Methods Effects of Type Erasure and Bridge Methods

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  • LDoms and Maintenance Mode

    - by Owen Allen
     I got a few questions about how maintenance mode works with LDoms. "I have a Control Domain that I need to do maintenance on. What does being put in maintenance mode actually do for a Control Domain?" Maintenance mode is what you use when you're going to be shutting a system down, or otherwise tinkering with it, and you don't want Ops Center to generate incidents and notification of incidents. Maintenance mode stops new incidents from being generated, but it doesn't stop polling, or monitoring, the system and it doesn't prevent alerts. "What does maintenance mode do with the guests on a Control Domain?" If you have auto recovery set and the Control Domain is a member of a server pool of eligible systems, putting the Control Domain in maintenance mode automatically migrates guests to an available Control Domain.  When a Control Domain is in maintenance mode, it is not eligible to receive guests and the placement policies for guest creation and for automatic recovery won't select this server as a possible destination. If there isn't a server pool or there aren't any eligible systems in the pool, the guests are shut down. You can select a logical domain from the Assets section to view the Dashboard for the virtual machine and the Automatic Recovery status, either Enabled or Disabled. To change the status, click the action in the Actions pane. "If I have to do maintenance on a system and I do not want to initiate auto-recovery, what do I have to do so that I can manually bring down the Control Domain (and all its Guest domains)?" Use the Disable Automatic Recovery action. "If I put a Control Domain into maintenance mode, does that also put the OS into maintenance mode?" No, just the Control Domain server. You have to put the OS into maintenance mode separately. "Also, is there an easy way to see what assets are in maintenance mode? Can we put assets into, or take them out of, maintenance mode on some sort of group level?" You can create a user-defined group that will automatically include assets in maintenance mode. The docs here explain how to set up these groups. You'll use a group rule that looks like this:

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  • Key ATG architecture principles

    - by Glen Borkowski
    Overview The purpose of this article is to describe some of the important foundational concepts of ATG.  This is not intended to cover all areas of the ATG platform, just the most important subset - the ones that allow ATG to be extremely flexible, configurable, high performance, etc.  For more information on these topics, please see the online product manuals. Modules The first concept is called the 'ATG Module'.  Simply put, you can think of modules as the building blocks for ATG applications.  The ATG development team builds the out of the box product using modules (these are the 'out of the box' modules).  Then, when a customer is implementing their site, they build their own modules that sit 'on top' of the out of the box ATG modules.  Modules can be very simple - containing minimal definition, and perhaps a small amount of configuration.  Alternatively, a module can be rather complex - containing custom logic, database schema definitions, configuration, one or more web applications, etc.  Modules generally will have dependencies on other modules (the modules beneath it).  For example, the Commerce Reference Store module (CRS) requires the DCS (out of the box commerce) module. Modules have a ton of value because they provide a way to decouple a customers implementation from the out of the box ATG modules.  This allows for a much easier job when it comes time to upgrade the ATG platform.  Modules are also a very useful way to group functionality into a single package which can be leveraged across multiple ATG applications. One very important thing to understand about modules, or more accurately, ATG as a whole, is that when you start ATG, you tell it what module(s) you want to start.  One of the first things ATG does is to look through all the modules you specified, and for each one, determine a list of modules that are also required to start (based on each modules dependencies).  Once this final, ordered list is determined, ATG continues to boot up.  One of the outputs from the ordered list of modules is that each module can contain it's own classes and configuration.  During boot, the ordered list of modules drives the unified classpath and configpath.  This is what determines which classes override others, and which configuration overrides other configuration.  Think of it as a layered approach. The structure of a module is well defined.  It simply looks like a folder in a filesystem that has certain other folders and files within it.  Here is a list of items that can appear in a module: MyModule: META-INF - this is required, along with a file called MANIFEST.MF which describes certain properties of the module.  One important property is what other modules this module depends on. config - this is typically present in most modules.  It defines a tree structure (folders containing properties files, XML, etc) that maps to ATG components (these are described below). lib - this contains the classes (typically in jarred format) for any code defined in this module j2ee - this is where any web-apps would be stored. src - in case you want to include the source code for this module, it's standard practice to put it here sql - if your module requires any additions to the database schema, you should place that schema here Here's a screenshots of a module: Modules can also contain sub-modules.  A dot-notation is used when referring to these sub-modules (i.e. MyModule.Versioned, where Versioned is a sub-module of MyModule). Finally, it is important to completely understand how modules work if you are going to be able to leverage them effectively.  There are many different ways to design modules you want to create, some approaches are better than others, especially if you plan to share functionality between multiple different ATG applications. Components A component in ATG can be thought of as a single item that performs a certain set of related tasks.  An example could be a ProductViews component - used to store information about what products the current customer has viewed.  Components have properties (also called attributes).  The ProductViews component could have properties like lastProductViewed (stores the ID of the last product viewed) or productViewList (stores the ID's of products viewed in order of their being viewed).  The previous examples of component properties would typically also offer get and set methods used to retrieve and store the property values.  Components typically will also offer other types of useful methods aside from get and set.  In the ProductViewed component, we might want to offer a hasViewed method which will tell you if the customer has viewed a certain product or not. Components are organized in a tree like hierarchy called 'nucleus'.  Nucleus is used to locate and instantiate ATG Components.  So, when you create a new ATG component, it will be able to be found 'within' nucleus.  Nucleus allows ATG components to reference one another - this is how components are strung together to perform meaningful work.  It's also a mechanism to prevent redundant configuration - define it once and refer to it from everywhere. Here is a screenshot of a component in nucleus:  Components can be extremely simple (i.e. a single property with a get method), or can be rather complex offering many properties and methods.  To be an ATG component, a few things are required: a class - you can reference an existing out of the box class or you could write your own a properties file - this is used to define your component the above items must be located 'within' nucleus by placing them in the correct spot in your module's config folder Within the properties file, you will need to point to the class you want to use: $class=com.mycompany.myclass You may also want to define the scope of the class (request, session, or global): $scope=session In summary, ATG Components live in nucleus, generally have links to other components, and provide some meaningful type of work.  You can configure components as well as extend their functionality by writing code. Repositories Repositories (a.k.a. Data Anywhere Architecture) is the mechanism that ATG uses to access data primarily stored in relational databases, but also LDAP or other backend systems.  ATG applications are required to be very high performance, and data access is critical in that if not handled properly, it could create a bottleneck.  ATG's repository functionality has been around for a long time - it's proven to be extremely scalable.  Developers new to ATG need to understand how repositories work as this is a critical aspect of the ATG architecture.   Repositories essentially map relational tables to objects in ATG, as well as handle caching.  ATG defines many repositories out of the box (i.e. user profile, catalog, orders, etc), and this is comprised of both the underlying database schema along with the associated repository definition files (XML).  It is fully expected that implementations will extend / change the out of the box repository definitions, so there is a prescribed approach to doing this.  The first thing to be sure of is to encapsulate your repository definition additions / changes within your own module (as described above).  The other important best practice is to never modify the out of the box schema - in other words, don't add columns to existing ATG tables, just create your own new tables.  These will help ensure you can easily upgrade your application at a later date. xml-combination As mentioned earlier, when you start ATG, the order of the modules will determine the final configpath.  Files within this configpath are 'layered' such that modules on top can override configuration of modules below it.  This is the same concept for repository definition files.  If you want to add a few properties to the out of the box user profile, you simply need to create an XML file containing only your additions, and place it in the correct location in your module.  At boot time, your definition will be combined (hence the term xml-combination) with the lower, out of the box modules, with the result being a user profile that contains everything (out of the box, plus your additions).  Aside from just adding properties, there are also ways to remove and change properties. types of properties Aside from the normal 'database backed' properties, there are a few other interesting types: transient properties - these are properties that are in memory, but not backed by any database column.  These are useful for temporary storage. java-backed properties - by nature, these are transient, but in addition, when you access this property (by called the get method) instead of looking up a piece of data, it performs some logic and returns the results.  'Age' is a good example - if you're storing a birth date on the profile, but your business rules are defined in terms of someones age, you could create a simple java-backed property to look at the birth date and compare it to the current date, and return the persons age. derived properties - this is what allows for inheritance within the repository structure.  You could define a property at the category level, and have the product inherit it's value as well as override it.  This is useful for setting defaults, with the ability to override. caching There are a number of different caching modes which are useful at different times depending on the nature of the data being cached.  For example, the simple cache mode is useful for things like user profiles.  This is because the user profile will typically only be used on a single instance of ATG at one time.  Simple cache mode is also useful for read-only types of data such as the product catalog.  Locked cache mode is useful when you need to ensure that only one ATG instance writes to a particular item at a time - an example would be a customers order.  There are many options in terms of configuring caching which are outside the scope of this article - please refer to the product manuals for more details. Other important concepts - out of scope for this article There are a whole host of concepts that are very important pieces to the ATG platform, but are out of scope for this article.  Here's a brief description of some of them: formhandlers - these are ATG components that handle form submissions by users. pipelines - these are configurable chains of logic that are used for things like handling a request (request pipeline) or checking out an order. special kinds of repositories (versioned, files, secure, ...) - there are a couple different types of repositories that are used in various situations.  See the manuals for more information. web development - JSP/ DSP tag library - ATG provides a traditional approach to developing web applications by providing a tag library called the DSP library.  This library is used throughout your JSP pages to interact with all the ATG components. messaging - a message sub-system used as another way for components to interact. personalization - ability for business users to define a personalized user experience for customers.  See the other blog posts related to personalization.

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  • CON6714 - Mixed-Language Development: Leveraging Native Code from Java

    - by Darryl Gove
    Here's the abstract from my JavaOne talk: There are some situations in which it is necessary to call native code (C/C++ compiled code) from Java applications. This session describes how to do this efficiently and how to performance-tune the resulting applications. The objectives for the session are: Explain reasons for using native code in Java applications Describe pitfalls of calling native code from Java Discuss performance-tuning of Java apps that use native code I'll cover how to call native code from Java, debugging native code, and then I'll dig into performance tuning the code. The talk is not going too deep on performance tuning - focusing on the JNI specific topics; I'll do a bit more about performance tuning in my OpenWorld talk later in the day.

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  • Commandline Purge in AS11

    - by Dheeraj Kumar
    AS11 - B2B offering consists of numerous features that have been made available via commandline approach. Most of these are supplement to the already available User Interface based approach. One such is purging of runtime data. The commandline purge option enables the users to purge the runtime data, based on various criteria. This is an ANT based command, provides the flexibility to selectively set the criteria to purge the runtime data. Providing the command line option also enables the administrator to purge in bulk, without visiting the B2B UI, which can also be used for automation purpose By default archival is turned on for purge activity. As a pre-requisite, the respective folder needs to be configured in database with the proper permission. When no filename is provided for archived data, the sysdate will be considered for filename. Below are the various options to purge the runtime data Normal 0 Option ANT option   Message state -Dmsgstate   Date range -Dfromdate,  -Dtodate Format : dd/mm/yyyy hh:mm AM/PM Trading partner -Dtp   Direction -Ddirection   Message Type -Dmsgtype   Agreement Name -Dagreement   IdType/ value -Didtype,  -Didvalue   Archive -Darchive True/false By default true Archive file name -Darchivename File name (optional), will be used when archive is set to true. Normal 0 Note: When using -Darchivename the value must be a unique file name. An existing file name used with -Darchivename throws an exception v\:* {behavior:url(#default#VML);} o\:* {behavior:url(#default#VML);} w\:* {behavior:url(#default#VML);} .shape {behavior:url(#default#VML);} Normal 0 Below are the few of ant commands and various options.   Purge based on date range and message state: Normal 0 ant -f ant-b2b-util.xml b2bpurge -Dmode=RT -Dfromdate="19/12/2009 1:04 AM" -Dtodate="19/12/2009 1:05 AM" -Dmsgstate=MSG_COMPLETE -Darchivename="filename.dmp"  Purge based on direction: Normal 0 ant -f ant-b2b-util.xml b2bpurge -Dmode=RT -Ddirection="OUTBOUND" Normal 0 Purge based on agreement Name: Normal 0 ant -f ant-b2b-util.xml b2bpurge -Dmode=RT -Dagreement="agreement_name" Normal 0 Purge based on Trading partner Name: Normal 0 ant -f ant-b2b-util.xml b2bpurge -Dmode=RT -Dtp=GlobalChips Normal 0 Purge based on Message State: Normal 0 ant -f ant-b2b-util.xml b2bpurge -Dmode=RT -Dmsgstate="MSG_COMPLETE" Normal 0 ant -f ant-b2b-util.xml b2bpurge -Dmode=RT -Ddirection="OUTBOUND" -Dmsgstate="MSG_COMPLETE"

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  • EL 3.0 Public Review - JSR 341 and Java EE 7 Moving Along

    - by arungupta
    Following closely on the lines of EL 3.0 Early Draft, the specification is now available for a Public Review. The JCP2 Process Document defines different stages of the specifications. This review period closes Jul 30, 2012. Some of the main goals of the JSR are to separate ELContext into parsing and evaluation contexts, adding operators like equality, string concatenation, etc, and integration with CDI. The section A.7 of the specification highlights the difference between Early Draft and Public Review. Download the Public Review and and follow the updates at el-spec.java.net. For more information about EL 3.0 (JSR 341), check out the JSR project on java.net. The archives of EG discussion are available at jsr341-experts and you can subscribe to the users@el-spec and other aliases on the Mailing Lists page.

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  • Chem eStandards 5.1 in Public Review

    - by michael.rowell
    The Open Applications Group has announced the opening of the 45 day public review period for Chem eStandards version 5.1. Interested parties have until 13 July to submit comments. There will be two webinars review sessions on 23 June and 24 June. The details of the webinars will be available soon. You can download the Chem eStandards review package. If you have any questions, contact Jim Wilson, the OAGi Chemical Council Architect.

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  • What are the files pushed to MDS?

    - by harsh.singla
    All files which are under AIAComponents will move to MDS. This contains EnterpriseObjectLibrary, EnterpriseBusinessServiceLibrary, ApplicationObjectLibrary, ApplicationBusinessServiceLibrary, B2BObjectLibrary, ExtensionServiceLibrary, and UtilityArtifacts. Also there are some common transformation (.xsl) files, which are kept under Transformations folder, moved to MDS. AIAConfigurationProperties.xml file will be there in MDS. Every cross reference (.xref) object will also be there. Every Domain value Map (.dvm) will also be there. Common fault policy, which by default included in composite during composite generation, if a user does not choose to customize fault policy. All these files are location under AIAMetaData directory and then placed in their respective folders. We are planning to put Error handling and BSR systems related data also to MDS.

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  • QotD: Sharat Chander on Java Embedded @ JavaOne

    - by $utils.escapeXML($entry.author)
    This year, JavaOne is expanding to offer business leaders a chance to participate, as well. I'm very proud to announce the deployment of "Java Embedded @ JavaOne." With the explosion of new unconnected devices and data creation, a new IT revolution is taking place in the embedded space. This net-new conference will specifically contain business content addressing the growing embedded ecosystem.As part of the "Java Embedded @ JavaOne" call-for-papers (CFP), interested speakers can continue forward and make business submissions, and due to high interest they also have the additional opportunity to make technical submissions for the flagship JavaOne conference, but _*ONLY*_ for the "Java ME, Java Card, Embedded and Devices" track. Sharat Chander in a set of posts on Java Embedded @ JavaOne to the JUG Leaders mailing list.

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  • Mobile apps suck time with the help of Java ME tech

    - by hinkmond
    Here's a new Flurry Mobile report on how Mobile Apps are sucking up more of our precious minutes in a day, even more than the Mobile Web. See: Mobile Apps suck more than Web Here's a quote: Flurry tracked 85,000 apps on [blah-blah-blah], BlackBerry, [yadda-yadda-yadda] and J2ME mobile devices, and their report includes a breakdown on how users spend their time. Greeeaaaaat... People are spending more time on mobile games and doing more Facebook and Twitter from their cell phones. Just what the world needed. Well, you know what they say: "Time == Money". So, the more time you spend, the more money someone, somewhere is getting... Hinkmond

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  • What would be the best way to get Apple to donate their JVM-work to OpenJDK?

    - by Thorbjørn Ravn Andersen
    It has been announced that Apple deprecates their JVM. It is a really nice piece of work giving an excellent user experience for Swing application on OS X, and it would be a pity if it just went away. As I see it the only realistic long term alternative to Apples own JVM is the OpenJDK unless Oracle chooses to take over the Apple JVM which I doubt as OS X is not a core platform for Oracle. But for this to work Apple needs to donate their enhancements to OpenJDK, and it needs to be under the GPL. They did so already with WebKit so there is precedent. What would be the best way to make them do so? Make a stackexchange poll? Get James Gosling and other high profile Java persons to say so? Email Steve Jobs? Suggestions? EDIT: Well, Apple has now promised to do so :) Shows that asking on StackExchange really MAKES A DIFFERENCE! Great!

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  • Efficient inline templates and C++

    - by Darryl Gove
    I've talked before about calling inline templates from C++, I've also talked about calling inline templates efficiently. This time I want to talk about efficiently calling inline templates from C++. The obvious starting point is that I need to declare the inline templates as being extern "C": extern "C" { int mytemplate(int); } This enables us to call it, but the call may not be very efficient because the compiler will treat it as a function call, and may produce suboptimal code based on that premise. So we need to add the no_side_effect pragma: extern "C" { int mytemplate(int); #pragma no_side_effect(mytemplate) } However, this may still not produce optimal code. We've discussed how the no_side_effect pragma cannot be combined with exceptions, well we know that the code cannot produce exceptions, but the compiler doesn't know that. If we tell the compiler that information it may be able to produce even better code. We can do this by adding the "throw()" keyword to the template declaration: extern "C" { int mytemplate(int) throw(); #pragma no_side_effect(mytemplate) } The following is an example of how these changes might improve performance. We can take our previous example code and migrate it to C++, adding the use of a try...catch construct: #include <iostream extern "C" { int lzd(int); #pragma no_side_effect(lzd) } int a; int c=0; class myclass { int routine(); }; int myclass::routine() { try { for(a=0; a<1000; a++) { c=lzd(c); } } catch(...) { std::cout << "Something happened" << std::endl; } return 0; } Compiling this produces a slightly suboptimal code sequence in the hot loop: $ CC -O -xtarget=T4 -S t.cpp t.il ... /* 0x0014 23 */ lzd %o0,%o0 /* 0x0018 21 */ add %l6,1,%l6 /* 0x001c */ cmp %l6,1000 /* 0x0020 */ bl,pt %icc,.L77000033 /* 0x0024 23 */ st %o0,[%l7] There's a store in the delay slot of the branch, so we're repeatedly storing data back to memory. If we change the function declaration to include "throw()", we get better code: $ CC -O -xtarget=T4 -S t.cpp t.il ... /* 0x0014 21 */ add %i1,1,%i1 /* 0x0018 23 */ lzd %o0,%o0 /* 0x001c 21 */ cmp %i1,999 /* 0x0020 */ ble,pt %icc,.L77000019 /* 0x0024 */ nop The store has gone, but the code is still suboptimal - there's a nop in the delay slot rather than useful work. However, it's good enough for this example. The point I'm making is that the compiler produces the better code with both the "throw()" and the no side effect pragma.

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  • Gradle Support in NetBeans IDE 7.2

    - by Geertjan
    Russel Winder and Steve Chin spent half an hour, and then gave up, setting up NetBeans IDE to use Gradle, because they couldn't find the NetBeans Gradle plugin, during Steve's NightHacking tour. That need happen no more because Attila Kelemen's NetBeans Gradle plugin is now available in the Plugin Manager in NetBeans IDE 7.2: Aside from opening Gradle-based applications, you can now also create new ones: Details and documentation: https://github.com/kelemen/netbeans-gradle-project

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  • OmniGraffle for iPad Now Supports VGA Output

    - by pat.shepherd
    I have (surprisingly) gotten a lot of comments over the last post about using OmniGraffle as an interactive EA tool.  The news flash/update is that it now supports VGA output.  I had sent a note to the developers and they responded that this was a highly sought after feature…well, they delivered. I have tried it informally and it works, thought there is a little lag between the drawing on the screen and the output, but it is not terrible. So buy yourself a VGA adapter and start trying it out in JAD (Joint Architecture Design) sessions. Here is a link to a couple little OG tutorials: "What's OmniGraffle for iPad", you say? Let us show you! Use the link below to see watch a guided tour of the powerful diagraming tool for the iPad. Videos - OmniGraffle for iPad - Products - The Omni Group

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  • CodePlex Daily Summary for Thursday, June 28, 2012

    CodePlex Daily Summary for Thursday, June 28, 2012Popular ReleasesDesigning Windows 8 Applications with C# and XAML: Chapters 1 - 7 Release Preview: Source code for all examples from Chapters 1 - 7 for the Release PreviewDataBooster - Extension to ADO.NET Data Provider: DataBooster Library for Oracle + SQL Server Beta2: This is a derivative library of dbParallel project http://dbparallel.codeplex.com. All above binaries releases require .NET Framework 4.0 or later. SQL Server support is always build-in (can't be unplugged). The first download (DLL) also requires ODP.NET to connect Oracle; The second download (DLL) also requires DataDirect(3.5) to connect Oracle; The third download (DLL) doesn't support Oracle. Please download the source code if the provider need to be replaced by others. For example ODP.NE...Microsoft Ajax Minifier: Microsoft Ajax Minifier 4.57: Fix for issue #18284: evaluating literal expressions in the pattern c1 * (x / c2) where c1/c2 is an integer value (as opposed to c2/c1 being the integer) caused the expression to be destroyed.Visual Studio ALM Quick Reference Guidance: v2 - Visual Studio 2010 (Japanese): Rex Tang (?? ??) http://blogs.msdn.com/b/willy-peter_schaub/archive/2011/12/08/introducing-the-visual-studio-alm-rangers-rex-tang.aspx, Takaho Yamaguchi (?? ??), Masashi Fujiwara (?? ??), localized and reviewed the Quick Reference Guidance for the Japanese communities, based on http://vsarquickguide.codeplex.com/releases/view/52402. The Japanese guidance is available in AllGuides and Everything packages. The AllGuides package contains guidances in PDF file format, while the Everything packag...Visual Studio Team Foundation Server Branching and Merging Guide: v1 - Visual Studio 2010 (Japanese): Rex Tang (?? ??) http://blogs.msdn.com/b/willy-peter_schaub/archive/2011/12/08/introducing-the-visual-studio-alm-rangers-rex-tang.aspx, Takaho Yamaguchi (?? ??), Hirokazu Higashino (?? ??), localized and reviewed the Branching Guidance for the Japanese communities, based on http://vsarbranchingguide.codeplex.com/releases/view/38849. The Japanese guidance is available in AllGuides and Everything packages. The AllGuides package contains guidances in PDF file format, while the Everything packag...SQL Server FineBuild: Version 3.1.0: Top SQL Server FineBuild Version 3.1.0This is the stable version of FineBuild for SQL Server 2012, 2008 R2, 2008 and 2005 Documentation FineBuild Wiki containing details of the FineBuild process Known Issues Limitations with this release FineBuild V3.1.0 Release Contents List of changes included in this release Please DonateFineBuild is free, but please donate what you think FineBuild is worth as everything goes to charity. Tearfund is one of the UK's leading relief and de...EasySL: RapidSL V2: Rewrite RapidSL UI Framework, Using Silverlight 5.0 EF4.1 Code First Ria Service SP2 + Lastest Silverlight Toolkit.SOLID by example: All examples: All solid examplesSiteMap Editor for Microsoft Dynamics CRM 2011: SiteMap Editor (1.1.1726.406): Use of new version of connection controls for a full support of OSDP authentication mechanism for CRM Online.StreamInsight Samples: StreamInsight Product Team Samples V2.1: These samples correspond to the new StreamInsight APIs introduced with V2.1.Umbraco CMS: Umbraco CMS 5.2: Development on Umbraco v5 discontinued After much discussion and consultation with leaders from the Umbraco community it was decided that work on the v5 branch would be discontinued with efforts being refocused on the stable and feature rich v4 branch. For full details as to why this decision was made please watch the CodeGarden 12 Keynote. What about all that hard work?!?? We are not binning everything and it does not mean that all work done on 5 is lost! we are taking all of the best and m...IIS Express Manager: IIS Express 0.31 B: V0.1B - 04 May, 2012 Initiated Project. V0.2B - 05May, 2012 1. Fixed small bug. Threw error when stop button was pressed in an already stopped application. 2. Removed start and stop button. Double clicking on list items will now stop / start the websites. 3. Improved code readability. 4. Changed Orientation of Buttons in UI. V0.3B - 06May, 2012 1. Complete modification of IISEM and process ID handling 2. IISEM is now capable of reflecting the existing IISExpress processes right from startup...CodeGenerate: CodeGenerate Alpha: The Project can auto generate C# code. Include BLL Layer、Domain Layer、IDAL Layer、DAL Layer. Support SqlServer And Oracle This is a alpha program,but which can run and generate code. Generate database table info into MS WordXDA ROM HUB: XDA ROM HUB v0.9: Kernel listing added -- Thanks to iONEx Added scripts installer button. Added "Nandroid On The Go" -- Perform a Nandroid backup without a PC! Added official Android app!ExtAspNet: ExtAspNet v3.1.8.2: +2012-06-24 v3.1.8 +????Grid???????（???????ExpandUnusedSpace????????）（??）。 -????MinColumnWidth（??????）。 -????AutoExpandColumn，???????????????（ColumnID）（?????ForceFitFirstTime??ForceFitAllTime，??????）。 -????AutoExpandColumnMax?AutoExpandColumnMin。 -????ForceFitFirstTime，????????????，??????????（????????????）。 -????ForceFitAllTime，????????????，??????????（??????????????????）。 -????VerticalScrollWidth，????????（??????????，0?????????????）。 -????grid/grid_forcefit.aspx。 -???????????En...AJAX Control Toolkit: June 2012 Release: AJAX Control Toolkit Release Notes - June 2012 Release Version 60623June 2012 release of the AJAX Control Toolkit. AJAX Control Toolkit .NET 4 – AJAX Control Toolkit for .NET 4 and sample site (Recommended). AJAX Control Toolkit .NET 3.5 – AJAX Control Toolkit for .NET 3.5 and sample site (Recommended). Notes: - The current version of the AJAX Control Toolkit is not compatible with ASP.NET 2.0. The latest version that is compatible with ASP.NET 2.0 can be found here: 11121. - Pages using ...WPF Application Framework (WAF): WPF Application Framework (WAF) 2.5.0.5: Version: 2.5.0.5 (Milestone 5): This release contains the source code of the WPF Application Framework (WAF) and the sample applications. Requirements .NET Framework 4.0 (The package contains a solution file for Visual Studio 2010) The unit test projects require Visual Studio 2010 Professional Changelog Legend: [B] Breaking change; [O] Marked member as obsolete WAF: Add IsInDesignMode property to the WafConfiguration class. WAF: Introduce the IModuleController interface. WAF: Add ...Windows 8 Metro RSS Reader: Metro RSS Reader.v7: Updated for Windows 8 Release Preview Changed background and foreground colors Used VariableSizeGrid layout to wrap blog posts with images Sort items with Images first, text-only last Enabled Caching to improve navigation between framesXDesigner.Development: First release: First releaseBlackJumboDog: Ver5.6.5: 2012.06.22 Ver5.6.5 　(1) FTP??????? EPSV ??　EPRT　???????New ProjectsAzure Log Viewer: Simple viewer for Windows Azure Diagnostics logs table.ChsoftDemo: chsoftDemoCodeDDD: CodeDDD is a set of lightweight Application Blocks with the goal of help on the development of Nlayered DDD ApplicationsCOM32: Serial communication componentCustom Email Template SharePoint: This solution customizes the Email text (Subject and the Message) sent to users on granting permssions to various sites.DBD::IngresII: DBD::IngresII is Ingres database driver for Perl.Dure: just for simplifying developments....FormAbstraction: FormAbstration allows you to add data objects to the session variable. You just have to name your fields the same as your properties and you're editing data.HD44780 Protocol Analyzer: HD44780 Protocol Analyzer for the Saleae Logic and Logic 16 analyzers. Supports 8 and 4 bit data transfer modes.IDisposable Azure Service Bus: A utility class that wraps interaction with a ServicBus inside an IDisposable object.IonoWumpus 2012: It's an awesome project! For the Hunt the Wumpus competition!Its My Story: It is All About Me and My Relatives, friends and followers..Kinect Gestures for Mayhem: Kinect Gesture for Mayhem is a module written for Mayhem. It implements hand gestures as events.KinectComposite: Using advanced Image Processing techniques along with environment information collected by Kinect this project attempt to create real-time composites.Lm.Common: aaaaaaOrBUO SVN: OrBUO SA/HS SVN ProjectOutlook Contact Category Correction Tool: Corrects contacts where the categories have been removed and you have a backup of your contacts at a time when your categories were still intact.Persian (Jalali-Shamsi) Calendar for Windows 8: This project is a Persian calendar for Metro UI on windows 8. It is a sample of using live tile on Metro UI.Schwazzle: New activity feed based on MS' famous CMSSDLGmud: ...SimpleWorkflow: Yet another simple workflow in .Net. The primary goal is to provide a quick lightweight dynamically constructed & reusable workflow API. SmartMeterParamSetting: Thread WPF UDPSPWikiTree 0.1.0.a: Purpose: Create an implementation of a JQuery Tree View Derive tree view content from wiki page library NOT rely on installed feature. (Created client-side)Sucdri: This is an Project Management ProjectUltimate Awesomeness, Inc.: It's cool!WallpaperDeleter: Simple program to delete the current background wallpaper image.zwp: wwww

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  • Grid Layouts in ADF Faces using Trinidad

    - by frank.nimphius
    Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} ADF Faces does provide a data table component but none to define grid layouts. Grids are common in web design and developers often try HTML table markup wrapped in an f:verbatim tag or directly added the page to build a desired layout. Usually these attempts fail, showing unpredictable results, However, ADF Faces does not provide a table layout component, but Apache MyFaces Trinidad does. The Trinidad trh:tableLayout component is a thin wrapper around the HTML table element and contains a series of row layout elements, trh:rowLayout. Each trh:rowLayout component may contain one or many trh:cellLayout components to format cells content. <trh:tableLayout id="tl1" halign="left">   <trh:rowLayout id="rl1" valign="top" halign="left">     <trh:cellFormat id="cf1" width="100" header="true">        <af:outputLabel value="Label 1" id="ol1"/>     </trh:cellFormat>     <trh:cellFormat id="cf2" header="true"                               width="300">        <af:outputLabel value="Label 2" id="outputLabel1"/>        </trh:cellFormat>      </trh:rowLayout>      <trh:rowLayout id="rowLayout1" valign="top" halign="left">        <trh:cellFormat id="cellFormat1" width="100" header="false">           <af:outputLabel value="Label 3" id="outputLabel2"/>        </trh:cellFormat>     </trh:rowLayout>        ... </trh:tableLayout> To add the Trinidad tag library to your ADF Faces projects ... Open the Component Palette and right mouse click into it Choose "Edit Tag Libraries" and select the Trinidad components. Move them to the "Selected Libraries" section and Ok the dialog.The first time you drag a Trinidad component to a page, the web.xml file is updated with the required filters Note: The Trinidad tags don't participate in the ADF Faces RC geometry management. However, they are JSF components that are part of the JSF request lifecycle. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} ADF Faces RC components work well with Trinidad layout components that don't use PPR. The PPR implementation of Trinidad is different from the one in ADF Faces. However, when you mix ADF Faces components with Trinidad components, avoid Trinidad components that have integrated PPR behavior. Only use passive Trinidad components.See:http://myfaces.apache.org/trinidad/trinidad-api/tagdoc/trh_tableLayout.htmlhttp://myfaces.apache.org/trinidad/trinidad-api/tagdoc/trh_rowLayout.htmlhttp://myfaces.apache.org/trinidad/trinidad-api/tagdoc/trh_cellFormat.html .

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  • Parallel Classloading Revisited: Fully Concurrent Loading

    - by davidholmes
    Java 7 introduced support for parallel classloading. A description of that project and its goals can be found here: http://openjdk.java.net/groups/core-libs/ClassLoaderProposal.html The solution for parallel classloading was to add to each class loader a ConcurrentHashMap, referenced through a new field, parallelLockMap. This contains a mapping from class names to Objects to use as a classloading lock for that class name. This was then used in the following way: protected Class loadClass(String name, boolean resolve) throws ClassNotFoundException { synchronized (getClassLoadingLock(name)) { // First, check if the class has already been loaded Class c = findLoadedClass(name); if (c == null) { long t0 = System.nanoTime(); try { if (parent != null) { c = parent.loadClass(name, false); } else { c = findBootstrapClassOrNull(name); } } catch (ClassNotFoundException e) { // ClassNotFoundException thrown if class not found // from the non-null parent class loader } if (c == null) { // If still not found, then invoke findClass in order // to find the class. long t1 = System.nanoTime(); c = findClass(name); // this is the defining class loader; record the stats sun.misc.PerfCounter.getParentDelegationTime().addTime(t1 - t0); sun.misc.PerfCounter.getFindClassTime().addElapsedTimeFrom(t1); sun.misc.PerfCounter.getFindClasses().increment(); } } if (resolve) { resolveClass(c); } return c; } } Where getClassLoadingLock simply does: protected Object getClassLoadingLock(String className) { Object lock = this; if (parallelLockMap != null) { Object newLock = new Object(); lock = parallelLockMap.putIfAbsent(className, newLock); if (lock == null) { lock = newLock; } } return lock; } This approach is very inefficient in terms of the space used per map and the number of maps. First, there is a map per-classloader. As per the code above under normal delegation the current classloader creates and acquires a lock for the given class, checks if it is already loaded, then asks its parent to load it; the parent in turn creates another lock in its own map, checks if the class is already loaded and then delegates to its parent and so on till the boot loader is invoked for which there is no map and no lock. So even in the simplest of applications, you will have two maps (in the system and extensions loaders) for every class that has to be loaded transitively from the application's main class. If you knew before hand which loader would actually load the class the locking would only need to be performed in that loader. As it stands the locking is completely unnecessary for all classes loaded by the boot loader. Secondly, once loading has completed and findClass will return the class, the lock and the map entry is completely unnecessary. But as it stands, the lock objects and their associated entries are never removed from the map. It is worth understanding exactly what the locking is intended to achieve, as this will help us understand potential remedies to the above inefficiencies. Given this is the support for parallel classloading, the class loader itself is unlikely to need to guard against concurrent load attempts - and if that were not the case it is likely that the classloader would need a different means to protect itself rather than a lock per class. Ultimately when a class file is located and the class has to be loaded, defineClass is called which calls into the VM - the VM does not require any locking at the Java level and uses its own mutexes for guarding its internal data structures (such as the system dictionary). The classloader locking is primarily needed to address the following situation: if two threads attempt to load the same class, one will initiate the request through the appropriate loader and eventually cause defineClass to be invoked. Meanwhile the second attempt will block trying to acquire the lock. Once the class is loaded the first thread will release the lock, allowing the second to acquire it. The second thread then sees that the class has now been loaded and will return that class. Neither thread can tell which did the loading and they both continue successfully. Consider if no lock was acquired in the classloader. Both threads will eventually locate the file for the class, read in the bytecodes and call defineClass to actually load the class. In this case the first to call defineClass will succeed, while the second will encounter an exception due to an attempted redefinition of an existing class. It is solely for this error condition that the lock has to be used. (Note that parallel capable classloaders should not need to be doing old deadlock-avoidance tricks like doing a wait() on the lock object\!). There are a number of obvious things we can try to solve this problem and they basically take three forms: Remove the need for locking. This might be achieved by having a new version of defineClass which acts like defineClassIfNotPresent - simply returning an existing Class rather than triggering an exception. Increase the coarseness of locking to reduce the number of lock objects and/or maps. For example, using a single shared lockMap instead of a per-loader lockMap. Reduce the lifetime of lock objects so that entries are removed from the map when no longer needed (eg remove after loading, use weak references to the lock objects and cleanup the map periodically). There are pros and cons to each of these approaches. Unfortunately a significant "con" is that the API introduced in Java 7 to support parallel classloading has essentially mandated that these locks do in fact exist, and they are accessible to the application code (indirectly through the classloader if it exposes them - which a custom loader might do - and regardless they are accessible to custom classloaders). So while we can reason that we could do parallel classloading with no locking, we can not implement this without breaking the specification for parallel classloading that was put in place for Java 7. Similarly we might reason that we can remove a mapping (and the lock object) because the class is already loaded, but this would again violate the specification because it can be reasoned that the following assertion should hold true: Object lock1 = loader.getClassLoadingLock(name); loader.loadClass(name); Object lock2 = loader.getClassLoadingLock(name); assert lock1 == lock2; Without modifying the specification, or at least doing some creative wordsmithing on it, options 1 and 3 are precluded. Even then there are caveats, for example if findLoadedClass is not atomic with respect to defineClass, then you can have concurrent calls to findLoadedClass from different threads and that could be expensive (this is also an argument against moving findLoadedClass outside the locked region - it may speed up the common case where the class is already loaded, but the cost of re-executing after acquiring the lock could be prohibitive. Even option 2 might need some wordsmithing on the specification because the specification for getClassLoadingLock states "returns a dedicated object associated with the specified class name". The question is, what does "dedicated" mean here? Does it mean unique in the sense that the returned object is only associated with the given class in the current loader? Or can the object actually guard loading of multiple classes, possibly across different class loaders? So it seems that changing the specification will be inevitable if we wish to do something here. In which case lets go for something that more cleanly defines what we want to be doing: fully concurrent class-loading. Note: defineClassIfNotPresent is already implemented in the VM as find_or_define_class. It is only used if the AllowParallelDefineClass flag is set. This gives us an easy hook into existing VM mechanics. Proposal: Fully Concurrent ClassLoaders The proposal is that we expand on the notion of a parallel capable class loader and define a "fully concurrent parallel capable class loader" or fully concurrent loader, for short. A fully concurrent loader uses no synchronization in loadClass and the VM uses the "parallel define class" mechanism. For a fully concurrent loader getClassLoadingLock() can return null (or perhaps not - it doesn't matter as we won't use the result anyway). At present we have not made any changes to this method. All the parallel capable JDK classloaders become fully concurrent loaders. This doesn't require any code re-design as none of the mechanisms implemented rely on the per-name locking provided by the parallelLockMap. This seems to give us a path to remove all locking at the Java level during classloading, while retaining full compatibility with Java 7 parallel capable loaders. Fully concurrent loaders will still encounter the performance penalty associated with concurrent attempts to find and prepare a class's bytecode for definition by the VM. What this penalty is depends on the number of concurrent load attempts possible (a function of the number of threads and the application logic, and dependent on the number of processors), and the costs associated with finding and preparing the bytecodes. This obviously has to be measured across a range of applications. Preliminary webrevs: http://cr.openjdk.java.net/~dholmes/concurrent-loaders/webrev.hotspot/ http://cr.openjdk.java.net/~dholmes/concurrent-loaders/webrev.jdk/ Please direct all comments to the mailing list [email protected].

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