我遇到问题，我不知道该怎么办。 所以，我创建了使用Java（JSP，Servlet的）一个小的Web应用程序& App Engine的API 它是工作在现场，但是当我部署它，它给我的错误：App Engine部署错误500
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和，在管理页面
java.lang.UnsupportedClassVersionError: persiste/EmployeServlet : Unsupported major.minor version 51.0
at com.google.appengine.runtime.Request.process-50f1863c6e652dbb(Request.java)
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:634)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:277)
at sun.reflect.GeneratedMethodAccessor5.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at java.lang.ClassLoader.loadClass(ClassLoader.java:266)
at org.mortbay.util.Loader.loadClass(Loader.java:91)
at org.mortbay.util.Loader.loadClass(Loader.java:71)
at org.mortbay.jetty.servlet.Holder.doStart(Holder.java:73)
at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:242)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at com.google.tracing.TraceContext$TraceContextRunnable.runInContext(TraceContext.java:449)
at com.google.tracing.TraceContext$TraceContextRunnable$1.run(TraceContext.java:455)
at com.google.tracing.TraceContext.runInContext(TraceContext.java:695)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContextNoUnref(TraceContext.java:333)
at com.google.tracing.TraceContext$AbstractTraceContextCallback.runInInheritedContext(TraceContext.java:325)
at com.google.tracing.TraceContext$TraceContextRunnable.run(TraceContext.java:453)
at java.lang.Thread.run(Thread.java:679)
当我改变的Java（从Java 7的Java 6）的日志和执行应用程序，我得到这个错误：
7 AOUT 2012 13时02分52秒com.google.apphosting.utils.jetty.JettyLogger警告 注意：失败Testv2：因为java.lang.UnsupportedClassVersionError：测试/ Testv2Servlet：不支持MAJOR.MINOR版本51.0
7 AOUT 2012 13:02:52 com.google.apphosting.utils.jetty.JettyLogger警告 注意：c[email protected]1522de2失败{/，D：\ Etudes \ Stage Dirham Express \ workspace \ testv2 \战争}：因为java.lang.UnsupportedClassVersionError：测试/ Testv2Servlet：不支持MAJOR.MINOR版本51.0
7 AOUT 2012 13时02分52秒com.google.apphosting.utils.jetty.JettyLogger警告 注意：失败JettyContainerService $一个piProxyHandler @ 15f4a7f：因为java.lang.UnsupportedClassVersionError：测试/ Testv2Servlet：不支持的版本MAJOR.MINOR 51.0
7 AOUT 2012 13时02分52秒com.google.apphosting.utils.jetty.JettyLogger警告 注意：异常 的java .lang.UnsupportedClassVersionError：测试/ Testv2Servlet：不支持的版本MAJOR.MINOR 51.0
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClassCond(ClassLoader.java:631)
at java.lang.ClassLoader.defineClass(ClassLoader.java:615)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:141)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:283)
at java.net.URLClassLoader.access$000(URLClassLoader.java:58)
at java.net.URLClassLoader$1.run(URLClassLoader.java:197)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at com.google.appengine.tools.development.IsolatedAppClassLoader.loadClass(IsolatedAppClassLoader.java:190)
at java.lang.ClassLoader.loadClass(ClassLoader.java:247)
at org.mortbay.util.Loader.loadClass(Loader.java:91)
at org.mortbay.util.Loader.loadClass(Loader.java:71)
at org.mortbay.jetty.servlet.Holder.doStart(Holder.java:73)
at org.mortbay.jetty.servlet.ServletHolder.doStart(ServletHolder.java:242)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:685)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1250)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:517)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:467)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:50)
at
com.google.appengine.tools.development.JettyContainerService.reloadWebApp（JettyContainerService.java:315）
at com.google.appengine.tools.development.JettyContainerService$ScannerListener.fileChanged(JettyContainerService.java:259)
at org.mortbay.util.Scanner.reportChange(Scanner.java:464)
at org.mortbay.util.Scanner.reportDifferences(Scanner.java:330)
at org.mortbay.util.Scanner.scan(Scanner.java:280)
at org.mortbay.util.Scanner$1.run(Scanner.java:232)
at java.util.TimerThread.mainLoop(Timer.java:512)
at java.util.TimerThread.run(Timer.java:462)
7août2012 13:02:52 com.google.apphosting.utils.jetty.JettyLogger警告 注意：com.google.ap[email protected]113e9fd在'D：\ Etudes \ Stage Dirham失败Express \ workspace \ testv2 \ war \ WEB-INF \ appengine-web.xml