题目内容：

HTTP Status 503 - This application is not currently available以下是错误代码?该怎么解决呢?
信息:Starting Servlet Engine:Apache Tomcat/6.0.16
2009-11-3 20:31:47 org.apache.tomcat.util.modeler.Registry registerComponent
严重:Null component Catalina:type=JspMonitor,name=jsp,WebModule=//localhost/testshooping,J2EEApplication=none,J2EEServer=none
2009-11-3 20:31:47 org.apache.catalina.startup.HostConfig deployDirectory
严重:Error deploying web application directory testshooping
java.lang.UnsupportedClassVersionError:Bad version number in .class file
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(Unknown Source)
at java.security.SecureClassLoader.defineClass(Unknown Source)
at org.apache.catalina.loader.WebappClassLoader.findClassInternal(WebappClassLoader.java:1819)
at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:872)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1327)
at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1206)
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:297)
at org.apache.catalina.startup.ContextConfig.start(ContextConfig.java:1064)
at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:261)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.core.StandardContext.start(StandardContext.java:4252)
at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:791)
at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:771)
at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:525)
at org.apache.catalina.startup.HostConfig.deployDirectory(HostConfig.java:924)
at org.apache.catalina.startup.HostConfig.deployDirectories(HostConfig.java:887)
at org.apache.catalina.startup.HostConfig.deployApps(HostConfig.java:492)
at org.apache.catalina.startup.HostConfig.start(HostConfig.java:1147)
at org.apache.catalina.startup.HostConfig.lifecycleEvent(HostConfig.java:311)
at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:117)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1053)
at org.apache.catalina.core.StandardHost.start(StandardHost.java:719)
at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:443)
at org.apache.catalina.core.StandardService.start(StandardService.java:516)
at org.apache.catalina.core.StandardServer.start(StandardServer.java:710)
at org.apache.catalina.startup.Catalina.start(Catalina.java:578)
还有部分代码因为字数限制没有贴出来