title: RESTEasy java.lang.LinkageError: LinkageError while defining class: org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
body: <p>I am trying to implement RESTEasy in my project, which is giving</p>
  
  <blockquote>
    <p>java.lang.LinkageError: LinkageError while defining
    class:org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher</p>
  </blockquote>
  
  <p>I am using websphere 6.1 and RESTEasy 2.1.0.GA</p>
  
  <p>The detail error is as follows:</p>
  
  <blockquote>
    <p>`Caused by: java.lang.LinkageError: LinkageError while defining class: org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher
    Could not be defined due to: (org/jboss/resteasy/plugins/server/servlet/HttpServletDispatcher) bad major version at offset=6
    This is often caused by having a class defined at multiple
    locations within the classloader hierarchy.  Other potential causes
    include compiling against an older or newer version of the class
    that has an incompatible method signature.
    Dumping the current context classloader hierarchy:
        ==> indicates defining classloader
    ==>[0] 
    com.ibm.ws.classloader.CompoundClassLoader@46204620
       Local ClassPath: 
       Delegation Mode: PARENT_FIRST
       [1] 
    com.ibm.ws.classloader.CompoundClassLoader@20ac20ac
       Local ClassPath: 
       Delegation Mode: PARENT_FIRST
       [2] com.ibm.ws.classloader.ProtectionClassLoader@49de49de
       [3] com.ibm.ws.bootstrap.ExtClassLoader@7b127b12
       [4] org.eclipse.osgi.internal.baseadaptor.DefaultClassLoader@2db22db2
       [5] sun.misc.Launcher$AppClassLoader@62e662e6
       [6] sun.misc.Launcher$ExtClassLoader@7fee7fee
    ---Original exception---
    java.lang.UnsupportedClassVersionError: (org/jboss/resteasy/plugins/server/servlet/HttpServletDispatcher) bad major version at offset=6
        at java.lang.ClassLoader.defineClassImpl(Native Method)
        at java.lang.ClassLoader.defineClass(ClassLoader.java:258)
        at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:151)
        at com.ibm.ws.classloader.CompoundClassLoader._defineClass(CompoundClassLoader.java:555)
        at com.ibm.ws.classloader.CompoundClassLoader.findClass(CompoundClassLoader.java:506)
        at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:380)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:597)
        at java.beans.Beans.instantiate(Beans.java:202)
        at java.beans.Beans.instantiate(Beans.java:63)
        at com.ibm.ws.webcontainer.servlet.ServletWrapper$1.run(ServletWrapper.java:1334)
        at com.ibm.ws.security.util.AccessController.doPrivileged(AccessController.java:118)
        at com.ibm.ws.webcontainer.servlet.ServletWrapper.loadServlet(ServletWrapper.java:1329)
        at com.ibm.ws.wswebcontainer.servlet.ServletWrapper.loadServlet(ServletWrapper.java:388)
        at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:410)
        at com.ibm.ws.wswebcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:478)
        at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:3440)
        at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:267)
        at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:815)
        at com.ibm.ws.wswebcontainer.WebContainer.handleRequest(WebContainer.java:1461)
        at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:119)
        at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:458)
        at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewInformation(HttpInboundLink.java:387)
        at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:102)
        at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:165)
        at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
        at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
        at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:136)
        at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:195)
        at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:743)
        at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:873)
        at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1473)</p>
  </blockquote>
  
  <p>--- end Original exception----</p>
  
  <pre><code>at com.ibm.ws.classloader.CompoundClassLoader._defineClass(CompoundClassLoader.java:602)
  at com.ibm.ws.classloader.CompoundClassLoader.findClass(CompoundClassLoader.java:506)
  at com.ibm.ws.classloader.CompoundClassLoader.loadClass(CompoundClassLoader.java:380)
  at java.lang.ClassLoader.loadClass(ClassLoader.java:597)
  at java.beans.Beans.instantiate(Beans.java:202)
  at java.beans.Beans.instantiate(Beans.java:63)
  at com.ibm.ws.webcontainer.servlet.ServletWrapper$1.run(ServletWrapper.java:1334)
  at com.ibm.ws.security.util.AccessController.doPrivileged(AccessController.java:118)
  at com.ibm.ws.webcontainer.servlet.ServletWrapper.loadServlet(ServletWrapper.java:1329)
  ... 19 more
  </code></pre>
  
  <p>`</p>