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• Eclipselink problem in a javase project

  - by arinte

  I am getting this error when I am running my eclipselink project. [EL Warning]: 2008.12.05 11:47:08.056--java.lang.NoClassDefFoundError: org/jboss/resource/adapter/jdbc/ValidConnectionChecker was thrown on attempt of PersistenceLoadProcessor to load class com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker. The class is ignored. Exception in thread "main" java.lang.NoClassDefFoundError: org/jboss/resource/adapter/jdbc/ValidConnectionChecker at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(Unknown Source) at java.security.SecureClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.defineClass(Unknown Source) at java.net.URLClassLoader.access$000(Unknown Source) at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.loadClass(PersistenceUnitProcessor.java:261) at org.eclipse.persistence.internal.jpa.metadata.MetadataProcessor.initPersistenceUnitClasses(MetadataProcessor.java:247) at org.eclipse.persistence.internal.jpa.metadata.MetadataProcessor.processEntityMappings(MetadataProcessor.java:422) at org.eclipse.persistence.internal.jpa.deployment.PersistenceUnitProcessor.processORMetadata(PersistenceUnitProcessor.java:299) at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.predeploy(EntityManagerSetupImpl.java:830) at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.callPredeploy(JPAInitializer.java:101) at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.initPersistenceUnits(JPAInitializer.java:149) at org.eclipse.persistence.internal.jpa.deployment.JPAInitializer.initialize(JPAInitializer.java:135) at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:104) at org.eclipse.persistence.jpa.PersistenceProvider.createEntityManagerFactory(PersistenceProvider.java:64) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:83) at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:60) at Main.main(Main.java:32) Caused by: java.lang.ClassNotFoundException: org.jboss.resource.adapter.jdbc.ValidConnectionChecker at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClassInternal(Unknown Source) ... 24 more Any ideas? Why would eclipselink need something from jboss? What jboss jar do I need. I would use open jpa, but for some reason after quit a few persists from my app it starts giving a bunch of stackoverflow errors.

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• How to solve "java.io.IOException: error=12, Cannot allocate memory" calling Runtime#exec()?

  - by Andrea Francia

  On my system I can't run a simple Java application that start a process. I don't know how to solve. Could you give me some hints how to solve? The program is: [root@newton sisma-acquirer]# cat prova.java import java.io.IOException; public class prova { public static void main(String[] args) throws IOException { Runtime.getRuntime().exec("ls"); } } The result is: [root@newton sisma-acquirer]# javac prova.java && java -cp . prova Exception in thread "main" java.io.IOException: Cannot run program "ls": java.io.IOException: error=12, Cannot allocate memory at java.lang.ProcessBuilder.start(ProcessBuilder.java:474) at java.lang.Runtime.exec(Runtime.java:610) at java.lang.Runtime.exec(Runtime.java:448) at java.lang.Runtime.exec(Runtime.java:345) at prova.main(prova.java:6) Caused by: java.io.IOException: java.io.IOException: error=12, Cannot allocate memory at java.lang.UNIXProcess.<init>(UNIXProcess.java:164) at java.lang.ProcessImpl.start(ProcessImpl.java:81) at java.lang.ProcessBuilder.start(ProcessBuilder.java:467) ... 4 more Configuration of the system: [root@newton sisma-acquirer]# java -version java version "1.6.0_0" OpenJDK Runtime Environment (IcedTea6 1.5) (fedora-18.b16.fc10-i386) OpenJDK Client VM (build 14.0-b15, mixed mode) [root@newton sisma-acquirer]# cat /etc/fedora-release Fedora release 10 (Cambridge) EDIT: Solution This solves my problem, I don't know exactly why: echo 0 /proc/sys/vm/overcommit_memory Up-votes for who is able to explain :) Additional informations, top output: top - 13:35:38 up 40 min, 2 users, load average: 0.43, 0.19, 0.12 Tasks: 129 total, 1 running, 128 sleeping, 0 stopped, 0 zombie Cpu(s): 1.5%us, 0.5%sy, 0.0%ni, 94.8%id, 3.2%wa, 0.0%hi, 0.0%si, 0.0%st Mem: 1033456k total, 587672k used, 445784k free, 51672k buffers Swap: 2031608k total, 0k used, 2031608k free, 188108k cached Additional informations, free output: [root@newton sisma-acquirer]# free total used free shared buffers cached Mem: 1033456 588548 444908 0 51704 188292 -/+ buffers/cache: 348552 684904 Swap: 2031608 0 2031608

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• BufferedReader.readLine() gives error java.net.SocketException: Software caused connection abort: re

  - by javatcp

  I am trying to code my program such that until the buffered reader gets something in readLine() from my tcp client it should keep running in the while loop checking but I get this error as soon as the program executes Mar 31, 2010 11:03:36 PM deswash.DESWashView$5 run SEVERE: null java.net.SocketException: Software caused connection abort: recv failed at java.net.SocketInputStream.socketRead0(Native Method) at java.net.SocketInputStream.read(SocketInputStream.java:129) at sun.nio.cs.StreamDecoder.readBytes(StreamDecoder.java:264) at sun.nio.cs.StreamDecoder.implRead(StreamDecoder.java:306) at sun.nio.cs.StreamDecoder.read(StreamDecoder.java:158) at java.io.InputStreamReader.read(InputStreamReader.java:167) at java.io.BufferedReader.fill(BufferedReader.java:136) at java.io.BufferedReader.readLine(BufferedReader.java:299) at java.io.BufferedReader.readLine(BufferedReader.java:362) at deswash.DESWashView$5.run(DESWashView.java:448) the second line in the following code throws the error while(running){ String temp = in.readLine(); if(!(temp.equals(null))){ int inid = Integer.parseInt(temp); stationList.add(inid); } }

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• Java Applet in Firefox

  - by prakash

  Hi All, I am facing a weird problem in Testing server while using applet (using embed tag) in my ASP.NET MVC application Applet works fine locally in both browsers IE and Firefox but when deployed to Testing server its throwing below exception for Firefox only (IE works fine). Please help me out in this basic: exception: javax.xml.parsers.FactoryConfigurationError: Provider <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> not found. java.lang.RuntimeException: javax.xml.parsers.FactoryConfigurationError: Provider <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> not found at sun.plugin2.applet.Plugin2Manager.createApplet(Unknown Source) at sun.plugin2.applet.Plugin2Manager$AppletExecutionRunnable.run(Unknown Source) at java.lang.Thread.run(Unknown Source) Caused by: javax.xml.parsers.FactoryConfigurationError: Provider <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> not found at javax.xml.parsers.DocumentBuilderFactory.newInstance(Unknown Source) at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:772) at org.apache.log4j.xml.DOMConfigurator.doConfigure(DOMConfigurator.java:696) at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:471) at org.apache.log4j.LogManager.<clinit>(LogManager.java:125) at org.apache.log4j.Logger.getLogger(Logger.java:105) at com.goldleaf.scanner.Logger.<init>(Unknown Source) at com.goldleaf.scanner.Logger.<init>(Unknown Source) at com.goldleaf.scanner.Logger$LoggerHolder.<clinit>(Unknown Source) at com.goldleaf.scanner.Logger.getInstance(Unknown Source) at com.goldleaf.scanner.ScannerApplet.<init>(Unknown Source) at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) at sun.reflect.NativeConstructorAccessorImpl.newInstance(Unknown Source) at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(Unknown Source) at java.lang.reflect.Constructor.newInstance(Unknown Source) at java.lang.Class.newInstance0(Unknown Source) at java.lang.Class.newInstance(Unknown Source) at sun.plugin2.applet.Plugin2Manager$12.run(Unknown Source) at java.awt.event.InvocationEvent.dispatch(Unknown Source) at java.awt.EventQueue.dispatchEvent(Unknown Source) at java.awt.EventDispatchThread.pumpOneEventForFilters(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForFilter(Unknown Source) at java.awt.EventDispatchThread.pumpEventsForHierarchy(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.pumpEvents(Unknown Source) at java.awt.EventDispatchThread.run(Unknown Source) Exception: java.lang.RuntimeException: javax.xml.parsers.FactoryConfigurationError: Provider <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> not found Ignored exception: java.lang.RuntimeException: javax.xml.parsers.FactoryConfigurationError: Provider <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd"> not found basic: Starting applet teardown basic: Finished applet teardown

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• java.lang.IllegalAccessError in Windows xp

  - by Priya.S

  Hi I have installed NetBeens 6.9.1 in my windows xp system. java web application wokring fine. But i have not get web method in my java web application. its error occurring. Error Message : init: deps-module-jar: deps-ear-jar: deps-jar: wsimport-init: Created dir: D:\javaprg\projects\myApp\build\generated-sources\jax-ws wsimport-client-userServiceService: Created dir: D:\javaprg\projects\myApp\build\generated\jax-wsCache\userServiceService D:\javaprg\projects\myApp\nbproject\jaxws-build.xml:31: java.lang.IllegalAccessError: tried to access class com.sun.tools.ws.Invoker from class com.sun.tools.ws.ant.WrapperTask at com.sun.tools.ws.ant.WrapperTask.createClassLoader(WrapperTask.java:85) at com.sun.istack.tools.ProtectedTask.execute(ProtectedTask.java:46) at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291) at sun.reflect.GeneratedMethodAccessor139.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) at java.lang.reflect.Method.invoke(Method.java:589) at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106) at org.apache.tools.ant.Task.perform(Task.java:348) at org.apache.tools.ant.Target.execute(Target.java:390) at org.apache.tools.ant.Target.performTasks(Target.java:411) at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1397) at org.apache.tools.ant.Project.executeTarget(Project.java:1366) at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41) at org.apache.tools.ant.Project.executeTargets(Project.java:1249) at org.apache.tools.ant.module.bridge.impl.BridgeImpl.run(BridgeImpl.java:281) at org.apache.tools.ant.module.run.TargetExecutor.run(TargetExecutor.java:539) at org.netbeans.core.execution.RunClassThread.run(RunClassThread.java:154) BUILD FAILED (total time: 1 second)

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• What's your "best practice" for the first Java EE Spring project?

  - by cringe

  I'm currently trying to get into the Java EE development with the Spring framework. As I'm new to Spring, it is hard to imaging how a good running project should start off. Do you have any best practices, tipps or major DO NOTs for a starter? How did you start with Spring - big project or small tutorial-like applications? Which technology did you use right away: AOP, complex Hibernate...

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• Java Play Mustache NPE Error

  - by zanedev

  We are getting a mustache play error in production (amazon linux EC2 AMI) but not in development (MACs) and we have tried upgrading the jvm, using the jdk instead, and changing from a tomcat deploy model to match our development environments as much as possible but nothing is working. Please any help would be greatly appreciated. We have lots of shared code in java and javascript using mustache and it would be a big deal to rewrite everything if we had to ditch mustache on the java side. 20:48:52,403 ERROR ~ @6al2dd0po Internal Server Error (500) for request GET /mystuff/people Execution exception (In {module:mustache-0.2}/app/play/modules/mustache/MustacheTags.java around line 32) NullPointerException occured : null play.exceptions.JavaExecutionException at play.templates.BaseTemplate.throwException(BaseTemplate.java:90) at play.templates.GroovyTemplate.internalRender(GroovyTemplate.java:257) at play.templates.Template.render(Template.java:26) at play.templates.GroovyTemplate.render(GroovyTemplate.java:187) at play.mvc.results.RenderTemplate.<init>(RenderTemplate.java:24) at play.mvc.Controller.renderTemplate(Controller.java:660) at play.mvc.Controller.renderTemplate(Controller.java:640) at play.mvc.Controller.render(Controller.java:695) at controllers.MyStuff.people(MyStuff.java:183) at play.mvc.ActionInvoker.invokeWithContinuation(ActionInvoker.java:548) at play.mvc.ActionInvoker.invoke(ActionInvoker.java:502) at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:478) at play.mvc.ActionInvoker.invokeControllerMethod(ActionInvoker.java:473) at play.mvc.ActionInvoker.invoke(ActionInvoker.java:161) at Invocation.HTTP Request(Play!) Caused by: java.lang.NullPointerException at play.modules.mustache.MustacheTags._template(MustacheTags.java:32) at play.modules.mustache.MustacheTags$_template.call(Unknown Source) at /app/views/User/people.html.(line:22) at play.templates.GroovyTemplate.internalRender(GroovyTemplate.java:232) ... 13 more

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• Java EE 6: JSF vs Servlet + JSP. Should I bother learning JSF?

  - by Harry Pham

  I am trying to get familiar with Java EE 6 by reading http://java.sun.com/javaee/6/docs/tutorial/doc/gexaf.html. I am a bit confused about the use of JSF. Usually, the way I develop my Web App would be, Servlet would act like a controller and JSP would act like a View in an MVC model. So Does JSF try to replace this structure? Below are the quote from the above tutorial: Servlet are best suited for service-oriented App and control function of presentation-oriented App like dispatching request JSF and Facelet are more appropriated for generating mark-up like XHTML, and generally used for presentation-oriented App Not sure if I understand the above quote too well, they did not explain too well what is service-oriented vs presentation-oriented. A JavaServer Faces application can map HTTP requests to component-specific event handling and manage components as stateful objects on the server. Any knowledgeable Java developer out there can give me a quick overview about JSF, JSP and Servlet? Do I integrate them all, or do I use them separated base on the App? if so then what kind of app use JSF in contrast with Servlet and JSP A JavaServer Faces application can map HTTP requests to component-specific event handling and manage components as stateful objects on the server. Sound like what servlet can do, but not sure about manage components as stateful objects on the server. Not even sure what that mean? Thanks in advance.

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• JRuby wrong element type class java.lang.String(array contains char) related to JAVA_HOME

  - by Daryl

  I am on Ubuntu x64 bit running: java version "1.6.0_18" OpenJDK Runtime Environment (IcedTea6 1.8) (6b18-1.8-0ubuntu1) OpenJDK 64-Bit Server VM (build 14.0-b16, mixed mode) and jruby 1.4.0 (ruby 1.8.7 patchlevel 174) (2010-02-11 6586) (OpenJDK 64-Bit Server VM 1.6.0_18) [amd64-java] I have this code running on my Windows 7 computer at home. I recently copied over my whole folder over to Ubuntu, installed java, jruby, and associated gems but I get this error when I run my main file: jruby run.rb test =================Processing FREDERICKSBURG_1.1======================= ERROR IN TESTING wrong element type class java.lang.String(array contains char) /home/daryl/Desktop/work/Code/geografikos/lib/sentence_splitter/splitter.rb:21:in `to_java' /home/daryl/Desktop/work/Code/geografikos/lib/sentence_splitter/splitter.rb:21:in `split' /home/daryl/Desktop/work/Code/geografikos/lib/models/page.rb:103:in `sentences' /home/daryl/Desktop/work/Code/geografikos/lib/extractor/lingpipe_svm.rb:34:in `extract' /home/daryl/Desktop/work/Code/geografikos/lib/extractor/geo_controller.rb:9:in `process' /home/daryl/Desktop/work/Code/geografikos/lib/extractor/geo_controller.rb:8:in `each' /home/daryl/Desktop/work/Code/geografikos/lib/extractor/geo_controller.rb:8:in `process' /home/daryl/Desktop/work/Code/geografikos/lib/extractor/geo_controller.rb:6:in `each' /home/daryl/Desktop/work/Code/geografikos/lib/extractor/geo_controller.rb:6:in `process' /home/daryl/Desktop/work/Code/geografikos/lib/statistics.rb:111:in `generate_all' /home/daryl/Desktop/work/Code/geografikos/lib/statistics.rb:105:in `each' /home/daryl/Desktop/work/Code/geografikos/lib/statistics.rb:105:in `generate_all' run.rb:56 The focus of the error is: ERROR IN TESTING wrong element type class java.lang.String(array contains char) Everything works fine on my windows machine. I figured I was getting this error because I did not have JAVA_HOME set however I added this to bashrc as: export JAVA_HOME=/usr/lib/jvm/java-1.6.0-openjdk and have confirmed: echo $JAVA_HOME /usr/lib/jvm/java-1.6.0-openjdk I can produce a similar error by removing my JAVA_HOME variable on windows: =================Processing FREDERICKSBURG_1.3======================= ERROR IN TESTING cannot convert instance of class org.jruby.RubyString to char C:/work/Code/geografikos/lib/sentence_splitter/splitter.rb:21:in `to_java' C:/work/Code/geografikos/lib/sentence_splitter/splitter.rb:21:in `split' C:/work/Code/geografikos/lib/models/page.rb:103:in `sentences' C:/work/Code/geografikos/lib/extractor/lingpipe_svm.rb:34:in `extract' C:/work/Code/geografikos/lib/extractor/geo_controller.rb:9:in `process' C:/work/Code/geografikos/lib/extractor/geo_controller.rb:8:in `each' C:/work/Code/geografikos/lib/extractor/geo_controller.rb:8:in `process' C:/work/Code/geografikos/lib/extractor/geo_controller.rb:6:in `each' C:/work/Code/geografikos/lib/extractor/geo_controller.rb:6:in `process' C:/work/Code/geografikos/lib/statistics.rb:111:in `generate_all' C:/work/Code/geografikos/lib/statistics.rb:105:in `each' C:/work/Code/geografikos/lib/statistics.rb:105:in `generate_all' run.rb:56 It is obviously not exactly the same but I have a feeling this has to do with the java path. You can probably derive from the error that I am just trying to convert a ruby variable to java using to_java. This works fine on my windows machine and I have confirmed the gems are the same but I don't think this has to do with gems. I lied. I changed my JAVA_HOME back on my windows machine and this error still occurs. So now the code doesn't run on either machine. I recently installed git on my windows machine and added the code to a repository. But I haven't really done anything with it. All it said was it will convert all LF to CRLF...That shouldn't change anything though should it? Any ideas on why I am now getting these errors? I haven't changed anything on my windows machine in months except for installing git.

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• Why is Java .Net so slow? [closed]

  - by 0101

  Ive just tried to use atmosphere.java.net (to see what it is) and I am not able to do it. Why is Java .NET so slow? Is it because they used Java in the server and are as incompetent as people whom write questions for SCJP? Does Sun have any competent employee and have you ever saw one ? (except the guy from Java Puzzles who made a career, because he made a lot of mistakes in Java API and now can teach us about it.) P.S. I would make it the "community wiki" if I could(to not get massive down-votes) but its not possible here, so hit me if you want to.

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• Why is Python slower than Java but faster than PHP

  - by good_computer

  I have many times seen various benchmarks that show how a bunch of languages perform on a given task. Always these benchmarks reveal that Python is slower then Java and faster than PHP. And I wonder why is that the case. Java, Python, and PHP run inside a virtual machine All three languages convert their programs into their custom byte codes that run on top of OS -- so none is running natively Both Java and Python can be "complied" (.pyc for Python) but the __main__ module for Python is not compiled Python and PHP are dynamically typed and Java statically -- is this the reason Java is faster, and if so, please explain how that affects speed. And, even if the dynamic-vs-static argument is correct, this does not explain why PHP is slower than Python -- because both are dynamic languages. You can see some benchmarks here and here, and here

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• JavaOne 2012 - Java Deployment on Mac OS X

  - by Sharon Zakhour

  Also at the JavaOne 2012 conference, Scott Kovatch presented a session on Deploying Your Application with OpenJDK 7 on Mac OS X. The session had special emphasis on how to deploy Java applications to the Mac App Store and discussed topics relevant to using Oracle Java on the Mac. Interested developers may find the following documentation useful: Packaging a Java App for Distribution on a Mac. For more information on installing and using Oracle Java for the Mac, refer to the following documentation: Mac FAQ JDK 7 Installation for Mac OS X JRE 7 Installation for Mac OS X Mac OS X Platform Install FAQ Note for Users of Macs that Include Apple Java 6

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• Goto for the Java Programming Language

  - by darcy

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

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• Free Java Workshops at Mobile World Congress

  - by Jacob Lehrbaum

  Are you attending Mobile World Congress in Barcelona next week? If so, you might want to register for Oracle's free workshop series taking place in the App Planet. We will be hosting a series of 25 workshops in our booth covering a range of topics that include: Benefits of Deploying Phones with Oracle Java Wireless Client Oracle's Embedded Java solutions for Machine-to-Machine applications Building better User Interfaces with the Lightweight User Interface Toolkit Resources to help you leverage Operator Network APIs in your Applications The Java Verified Program: new trusted status and other recent initiatives Building better mobile enterprise applications with Oracle's ADF Mobile technology How to build a profitable mobile applications business with Java ME Guest speakers from Orange, Telefonica and from leading ISVs REGISTER NOW for one or more workshops in the Oracle Java Booth 7C18 located in the App Planet. Oh, and did we mention there might be giveaways? Note: you may need to "sign out" if you have an account on Oracle.com in order to see the registration page

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• Starting java processes with Upstart

  - by user265330

  I want to start a java process using Upstart. Currently, on our OpenSuSE servers, I use the System V init system to achieve this, but on our Ubuntu servers I'd rather use Upstart. But I have two questions... I have an Upstart job (a task) that configures the server, called, say, myconfig. And in the job that starts my java processes I ostensibly have: start on stopped myconfig exec /path/to/myjavastartscript.sh myjavastartscript.sh runs 'java -classpath blah MyClass'. In System V init, starting the service runs 'nohup /path/to/myjavastartscript.sh &'. So my first question is whether I still need to do the nohup or run-in-background with the exec command? When running, MyClass starts other Java processes. In System V init, the service stop just looks for java processes owned by a certain user and kills them. My second question is how could I control the termination of these processes with Upstart?

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• ARM TechCON 2013 presentation: Java SE 8 Compact Profiles

  - by hinkmond

  I'll be giving a technical session presentation at ARM TechCON 2013 this Wed. 10/30 @ 11:30am. So if you are in Santa Clara, Calif. come over to the conference and hear me present on this fun-filled topic! See: Java SE 8 Compact Profiles Here's a quote: Java SE 8 has a new Compact Profiles feature that allows for three new specification–compliant subsets of Java SE 8 APIs. Compact Profiles will enable the creation of Java SE 8 runtimes that support configurations that previously were possible only with the CDC version of J2ME... It's an important topic in today's mad, mad world of Embedded Development. You never want to develop in Java for small devices with your Compact Profiles. It's just not what you'd want! Hinkmond

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• Impact of changing from PHP to Java after 1 year or 6 months

  - by user62909

  I'm MCA final year student and I have very poor school record and had 2 years of gap. I'm first class with distinction in graduation and in post graduation is first class.Companies are coming for campus recruitment.I have very less companies like 4 or 5 who don't impose any criteria. there is a company who work on PHP and i have cleared its aptitude test and technical only HR remaining. I'm actually interested in Java and have knowledge about it but company work on PHP.I was fretting about If i work on PHP for 6 or 1 year can I change later to Java ? because i will also have experience of 6 or 12 months ? Will be considered an experienced employee if I apply for java developer later ? Will manager think that I worked in PHP and not allowed for Java ? Will I have to pursue java OCJP certification so i can get job even after 1 year experience of PHP ? Only 8 days are remaining for Hr round so please need help

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• On-demand Webcast: Java in the Smart Grid

  - by Jacob Lehrbaum

  The Smart Grid is one of the most significant evolutions of our utility infrastructure in recent history. This innovative grid will soon revolutionize how utilities manage and control the energy in our homes--helping utilities reduce energy usage during peak hours, improve overall energy efficiency, and lower your energy bills. If you'd like to learn more about the Smart Grid and the role that Java is poised to play in this important initiative you can check out our on-demand webcast. We'll show you how Java solutions--including Java ME and Java SE for Embedded --can help build devices and infrastructure that take advantage of this new market. As the world's most popular developer language, Java enables you to work with a wide range of developers and provides access to tools and resources to build smarter devices, faster and more affordably.

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• Look after your tribe of Pygmies with Java ME technology

  - by hinkmond

  Here's a game that is crossing over from the iDrone to the more lucrative Java ME cell phone market. See: Pocket God on Java ME Here's a quote: Massive casual iPhone hit Pocket God has parted the format waves and walked over to the land of Java mobiles, courtesy of AMA. The game sees you take control of an omnipotent, omnipresent, and (possibly) naughty deity, looking after your tribe of Pygmies... Everyone knows that there are more Java ME feature phones than grains of sand on a Pocket God island beach. So, when iDrone games are done piddlying around on a lesser platform, they move over to Java ME where things are really happening. Hinkmond

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• Pros and cons of developing modern services in Java

  - by r3mus

  I'm interested in the philosophical and architectural justification (or lack thereof) in using Java to develop in today's modern world (exclude mobile/embedded platforms of course). Why would one choose to develop (or not develop) a back-end in Java? Why would one choose to develop (or not develop) a front-end UI in Java? Why do large enterprises lean towards developing in Java rather than adopt more modern (and standardized) technologies? *disclaimer: I'm not a fan of Java in the enterprise, I'm simply curious what drives enterprises to continue the trend.

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• Java plugin is not working on some sites

  - by Jay

  I have icedtea6-plugin installed on my Ubuntu box. The weird thing is, when I am browsing the internet, certain website are able to use the Java and some websites are not. For instance, I am able to log in to my bank at nordea.dk. They use a Java applet to authenticate the user. But when I try to use keepvid.com, it says "Loading Java Applet". And then after a minute or two it says "Error: Please click here to download Java. If you already have Java, please restart your browser and try again." The thing is I've restarted my computer, closed and opened my browser(chromium) and none of it seems to help. Could someone please point me in the right direction to solve this problem? Thanks.

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• Java still dont recognize horizontal scroll (right click) 14.04

  - by user289280

  I am totally trackpoint fan, I use it all the time and have disablet my touchpad. Due to my study I work a lot with MATLAB, but MATLAB uses Java, and horizontal scroll does not be recognized by java as I already reat in many other threats(well it recognizes as right click :S ). There seems to be no solution for that and disable horizontal scroll in matlab is no solution for me at all. Does anybody know about a fix for that or somehow to enable horizontal scroll java. This really drives me crazy. HELP! I have Ubuntu 14.04 with java version: java version "1.7.0_55" OpenJDK Runtime Environment (IcedTea 2.4.7) (7u55-2.4.7-1ubuntu1) OpenJDK 64-Bit Server VM (build 24.51-b03, mixed mode) Thank you in advance!

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• Matching my skills with Java and Web Programming

  - by John R

  here is my main question: What is the most common way that Java is used in web development? The reason I ask: I am currently in the process of finding my first internship. Every employer has a separate set of languages, technologies and acronyms they want their candidates to know. In school I did well with Java. As a hobby and interest I have developed a handful of web pages widgets, scripts, etc. My university emphasized Java, C and theory. My hobbies emphasize HTML, PHP, JavaScript, CSS, and a little jQuery, etc. I can't learn a dozen different technologies to satisfy most prospective employers (in what is left of the summer). I think my best bet is combine my skills with Java and my interests in web development. That brings me back to my original question: What is the most common way that Java is used in web development?

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• Integrating Java webapps with Adobe Professional: Resources?

  - by Steve

  I'm interested in learning what resources there are for integrating Java and Adobe Professional, in general. If it helps, my projects already use the Spring Framework. My boss is particularly interested in being able to fill out a PDF form from within a Java webapp and have that data go directly to our database. She mentioned that .net had a lot of bridges to Adobe Professional. I would rather new projects be in Java so I am eager to find if there are any easy bridges between Java and Adobe Professional. Thanks in advance for any information. So far a Google search on "Java Adobe Professional" didn't turn up anything, so I thought I would ask here. Thanks.

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• Java vs COBOL programming examples

  - by Jodi

  I am a COBOL programmer, desperately trying to learn and program Java. Although I understand the OO priciples and concepts, I am at a lost putting all together. I am trying to find some examples on how code will look in COBOL vs Java - something a bit more complicated than "hello world" [I am past that initial headache! :-)], that includes OO principles - basically, a decent 1000+ liner in COBOL, with the Java code to work through. After working through book after book, doing the examples, and even writing small java programs at work, I think working through an example I can compare will be the best way to getting my thinking cap converted, and being able to do in Java what I can do after 10 years with COBOL. Can anybody help?

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