Google应用引擎返回错误日志:不受支持的major.minor版本51.0

Question

我刚刚构建了一个示例应用程序来测试谷歌应用引擎和谷歌网络工具包功能,使用RPC服务和谷歌应用引擎与JDO.该服务适用于本地.但是在我将它部署到GAE并运行后,它会向我显示标题所示的错误.我使用JRE7来编译应用程序.这是我的错误日志:

Uncaught exception from servlet
java.lang.UnsupportedClassVersionError: com/gwt/myexample/server/EmployeeServiceImpl:
Unsupported major.minor version 51.0
at com.google.appengine.runtime.Request.process-e8c21a25e91f709f(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)

我的应用程序链接:http://jdodemo02.appspot.com/ 任何建议请):

Answer 1

使用Java SE 6编译应用程序.GAE不支持Java SE 7.本地可行,因为GAE模拟器在本地JDK之上运行.