I have deployed a WAR file in the webapps folder in my tomcat. And when I am starting my tomcat, like below
C:\apache-tomcat-6.0.35\bin>startup.bat
Using CATALINA_BASE: "C:\apache-tomcat-6.0.35"
Using CATALINA_HOME: "C:\apache-tomcat-6.0.35"
Using CATALINA_TMPDIR: "C:\apache-tomcat-6.0.35\temp"
Using JRE_HOME: "C:\Program Files (x86)\IBM\RationalSDLC\Common\Java5.0\jre"
Using CLASSPATH: "C:\apache-tomcat-6.0.35\bin\bootstrap.jar"
I am getting this below exception-
SEVERE: Error deploying web application archive DirectoryServer.war
java.lang.UnsupportedClassVersionError: (com/services/rest/Listener) bad major version at offset=6 (unable to load class com.services.rest.Listener)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2822)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1159)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1647)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1526)
at org.apache.catalina.startup.WebAnnotationSet.loadClassAnnotation(WebAnnotationSet.java:145)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationListenerAnnotations(WebAnnotationSet.java:73)
at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:56)
at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:297)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1078)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:261)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4612)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:799)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:779)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:601)
at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:943)
at org.apache.catalina.startup.HostConfig.deployWARs(HostConfig.java:778)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:504)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1317)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:324)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:142)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1065)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:840)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1057)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:463)
at org.apache.catalina.core.StandardService.start(StandardService.java:525)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:754)
at org.apache.catalina.startup.Catalina.start(Catalina.java:595)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:79)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:618)
at org.apache.catalina.startup.Bootstrap.start(Bootstrap.java:289)
at org.apache.catalina.startup.Bootstrap.main(Bootstrap.java:414)
And this is my JAVA version-
C:\apache-tomcat-6.0.35\bin>java -version
java version "1.6.0_26"
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode)
Can anyone provide any suggestion why is it happening?
You have essentially compiled your code with JDK 1.6 but running it with Java 5 - Just ensure a Java 6 runtime.
Even I faced same problem. The problem is inappropriate class version, for ex. compiling with different jre.
Solution: IF you are using Eclipse or RAD, set change compiler setting as per your requirement and also change same setting to project configuration by clicking on "Configure Project specific setting". Windows->Preferences->Compiler-> click on link "Configure Project specific setting".
For me the fix was to set the JAVA_Home system variable to the correct path.
It is a compiler issue. Make sure all your modules are configured with java 1.5 as a compiler. Window-->preference--> Java --> Compiler. Make sure 1.5 is selected.
来源：https://stackoverflow.com/questions/12850336/java-lang-unsupportedclassversionerror-bad-major-version-at-offset-6