Tomcat7 War File Issue

Question

This may be asked previously but none of them is solving my problem

I have made a servlet and I want to host it in tomcat7. The servlet is running perfectly when I run it in tomcat7 using eclipse(Run on server)

echo $CATALINA_HOME is /usr/share/tomcat7

However the webapp folder is found in /var/lib/tomcat7

I made a war file using eclipse[file->export->web->war]

ERROR

11 Sep, 2013 12:30:51 AM org.apache.catalina.core.StandardService startInternal
INFO: Starting service Catalina
11 Sep, 2013 12:30:51 AM org.apache.catalina.core.StandardEngine startInternal
INFO: Starting Servlet Engine: Apache Tomcat/7.0.26
11 Sep, 2013 12:30:51 AM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor /etc/tomcat7/Catalina/localhost/host-manager.xml
11 Sep, 2013 12:30:58 AM org.apache.catalina.util.SessionIdGenerator createSecureRandom
INFO: Creation of SecureRandom instance for session ID generation using [SHA1PRNG] took [6,114] milliseconds.
11 Sep, 2013 12:30:58 AM org.apache.catalina.startup.HostConfig deployDescriptor
INFO: Deploying configuration descriptor /etc/tomcat7/Catalina/localhost/manager.xml
11 Sep, 2013 12:30:58 AM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive /var/lib/tomcat7/webapps/sms.war
11 Sep, 2013 12:30:58 AM org.apache.catalina.core.ContainerBase addChildInternal
SEVERE: ContainerBase.addChild: start: 
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/sms]]
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:895)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:958)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1599)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:679)
Caused by: java.lang.UnsupportedClassVersionError: org/raxa/module/handlesms/IncomingSMS : Unsupported major.minor version 51.0 (unable to load class org.raxa.module.handlesms.IncomingSMS)
    at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:2840)
    at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1160)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1668)
    at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1546)
    at org.apache.catalina.startup.WebAnnotationSet.loadApplicationServletAnnotations(WebAnnotationSet.java:108)
    at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:58)
    at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:381)
    at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:858)
    at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:345)
    at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119)
    at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5161)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150)
    ... 11 more
11 Sep, 2013 12:30:58 AM org.apache.catalina.startup.HostConfig deployWAR
SEVERE: Error deploying web application archive /var/lib/tomcat7/webapps/sms.war
java.lang.IllegalStateException: ContainerBase.addChild: start: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/sms]]
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:898)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:871)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:615)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:958)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1599)
    at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471)
    at java.util.concurrent.FutureTask$Sync.innerRun(FutureTask.java:334)
    at java.util.concurrent.FutureTask.run(FutureTask.java:166)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1146)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
    at java.lang.Thread.run(Thread.java:679)
11 Sep, 2013 12:30:58 AM org.apache.catalina.startup.HostConfig deployWAR
INFO: Deploying web application archive /var/lib/tomcat7/webapps/sample.war
11 Sep, 2013 12:30:58 AM org.apache.catalina.startup.HostConfig deployDirectory
INFO: Deploying web application directory /var/lib/tomcat7/webapps/ROOT
11 Sep, 2013 12:30:59 AM org.apache.coyote.AbstractProtocol start
INFO: Starting ProtocolHandler ["http-bio-8080"]
11 Sep, 2013 12:30:59 AM org.apache.catalina.startup.Catalina start
INFO: Server startup in 7455 ms

I tried to create the war file using apache ant also but its giving the same error.

In eclipse I provided the tomcat installation directory to be /usr/share/tomcat7 i.e $catalina_home

java-version

java version "1.7.0_21"
Java(TM) SE Runtime Environment (build 1.7.0_21-b11)
Java HotSpot(TM) 64-Bit Server VM (build 23.21-b01, mixed mode)

SOLUTION set tomcat java_home to the the system java-version

Tutorial:Link to set java_home of tomcat7

Answer 1

Actually the main point of your Exception is the java.lang.UnsupportedClassVersionError Unsupported major.minor version 51.0
This means that at least java 7 has to be used to launch tomcat.

you should check with which jdk you start tomcat.
for sure it is lower as java 7. It is not necessary matching the java -version return

For going deeper on the java.lang.UnsupportedClassVersionError:
http://javarevisited.blogspot.ch/2011/07/javalangunsupportedclassversionerror.html