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Problems On Running Embedded EJB In Weblogic

If you have ever test embedded EJB in Weblogic with JUnit, you probably have received exceptions like below: Exception details: java.lang.OutOfMemoryError: PermGen space at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:791) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:449) at java.net.URLClassLoader.access$100(URLClassLoader.java:71) at java.net.URLClassLoader$1.run(URLClassLoader.java:361) at java.net.URLClassLoader$1.run(URLClassLoader.java:355) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:354) at java.lang.ClassLoader.loadClass(ClassLoader.java:423) at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:308) at java.lang.ClassLoader.loadClass(ClassLoader.java:356) at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:791) at […]

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Hadoop Exceptions – JobTracker Couldn’t Start

Recently, I’m learning hadoop, but encountered many problems, here is the jobtracker problem. System environment: ubuntu 13.04, hadoop 1.1.2 Exception description: ************************************************************/ 2013-05-19 13:38:50,190 INFO org.apache.hadoop.mapred.JobTracker: STARTUP_MSG: /************************************************************ STARTUP_MSG: Starting JobTracker STARTUP_MSG: host = xuqian-desktop/127.0.1.1 STARTUP_MSG: args = [] STARTUP_MSG: version = 1.1.2 STARTUP_MSG: build = https://svn.apache.org/repos/asf/hadoop/common/branches/branch-1.1 -r 1440782; compiled by ‘hortonfo’ on Thu Jan […]

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Best 5 Free Java eBooks

Here are 5 ebooks for java beginners, they can be free downloaded, but should only for informative purposes and strictly for personal, private use. After you reading one or more these books, you will be quickly get familiar with Java. 1. Head First Java, 2nd Edition   Book Description Head First Java delivers a highly […]

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Java EE 6 For Beginners – JSF 2.1 Tutorial Basic Hello World

Introduction Hello everybody! Today I’ll show you how to create a very simple Hello World project using JSF technology. JSF, JavaServer Faces,Β is a server-side component framework for building Java technology-based web applications. For more information about JSF, please read Oracle Java EE tutorial, JSF chapter. Again, Thank all of you for pointing out my mistakes! […]

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