关于GOOGLE APP 启动的错误
部署到GOOGLE服务器上没有问题 但ECLIPSE中启动就会报一下错误：
2011-10-8 3:38:45 com.google.appengine.tools.development.agent.AppEngineDevAgent premain
严重: Unable to load the App Engine dev agent. Security restrictions will not be completely emulated.
java.lang.reflect.UndeclaredThrowableException
at com.google.appengine.tools.development.agent.$Proxy0.run(Unknown Source)
at com.google.appengine.tools.development.agent.AppEngineDevAgent.premain(AppEngineDevAgent.java:62)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:141)
Caused by: java.lang.reflect.InvocationTargetException
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
at java.lang.reflect.Method.invoke(Method.java:585)
at com.google.apphosting.utils.clearcast.ClearCast$CasterImpl$ProxyHandler.invoke(ClearCast.java:411)
... 7 more
Caused by: java.lang.UnsupportedClassVersionError: Bad version number in .class file
at java.lang.ClassLoader.defineClass1(Native Method)
at java.lang.ClassLoader.defineClass(ClassLoader.java:620)
at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:124)
at java.net.URLClassLoader.defineClass(URLClassLoader.java:260)
at java.net.URLClassLoader.access$100(URLClassLoader.java:56)
at java.net.URLClassLoader$1.run(URLClassLoader.java:195)
at java.security.AccessController.doPrivileged(Native Method)
at java.net.URLClassLoader.findClass(URLClassLoader.java:188)
at java.lang.ClassLoader.loadClass(ClassLoader.java:306)
at java.lang.ClassLoader.loadClass(ClassLoader.java:251)
at java.lang.ClassLoader.loadClassInternal(ClassLoader.java:319)
at com.google.appengine.tools.development.agent.impl.AgentImpl.run(AgentImpl.java:25)
... 12 more
Usage: <dev-appserver> [options] <war directory>

Options:
 --help, -h Show this help message and exit.
 --server=SERVER The server to use to determine the latest
  -s SERVER SDK version.
 --address=ADDRESS The address of the interface on the local machine
  -a ADDRESS to bind to (or 0.0.0.0 for all interfaces).
 --port=PORT The port number to bind to on the local machine.
  -p PORT
 --sdk_root=root Overrides where the SDK is located.
 --disable_update_check Disable the check for newer SDK versions.


------解决方案--------------------
bad version number in .class file
jdk的版本不一致，建议用一样的jdk将类重新编译一下

------解决方案--------------------
Caused by: java.lang.UnsupportedClassVersionError: Bad version number in .class file
版本问题