直接通过App Engine Connected Android Project生成一个项目，Appengine成功，但是Android app不成功。

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直接通过App Engine Connected Android Project生成一个项目，Appengine成功，但是Android app不成功。运行时出现如下错误，请各位看官帮忙看看：
04-03 13:56:21.826: I/dalvikvm(1389): threadid=3: reacting to signal 3
04-03 13:56:22.008: I/dalvikvm(1389): Wrote stack traces to '/data/anr/traces.txt'
04-03 13:56:22.246: D/AndroidRuntime(1389): Shutting down VM
04-03 13:56:22.246: W/dalvikvm(1389): threadid=1: thread exiting with uncaught exception (group=0x409c01f8)
04-03 13:56:22.276: E/AndroidRuntime(1389): FATAL EXCEPTION: main
04-03 13:56:22.276: E/AndroidRuntime(1389): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.mydiary0023/com.mydiary0023.MainActivity}: java.lang.ClassNotFoundException: com.mydiary0023.MainActivity
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1880)
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1981)
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.app.ActivityThread.access$600(ActivityThread.java:123)
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1147)
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.os.Handler.dispatchMessage(Handler.java:99)
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.os.Looper.loop(Looper.java:137)
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.app.ActivityThread.main(ActivityThread.java:4424)
04-03 13:56:22.276: E/AndroidRuntime(1389): at java.lang.reflect.Method.invokeNative(Native Method)
04-03 13:56:22.276: E/AndroidRuntime(1389): at java.lang.reflect.Method.invoke(Method.java:511)
04-03 13:56:22.276: E/AndroidRuntime(1389): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
04-03 13:56:22.276: E/AndroidRuntime(1389): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
04-03 13:56:22.276: E/AndroidRuntime(1389): at dalvik.system.NativeStart.main(Native Method)
04-03 13:56:22.276: E/AndroidRuntime(1389): Caused by: java.lang.ClassNotFoundException: com.mydiary0023.MainActivity
04-03 13:56:22.276: E/AndroidRuntime(1389): at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
04-03 13:56:22.276: E/AndroidRuntime(1389): at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
04-03 13:56:22.276: E/AndroidRuntime(1389): at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.app.Instrumentation.newActivity(Instrumentation.java:1023)
04-03 13:56:22.276: E/AndroidRuntime(1389): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1871)
04-03 13:56:22.276: E/AndroidRuntime(1389): ... 11 more
04-03 13:56:22.336: I/dalvikvm(1389): threadid=3: reacting to signal 3
04-03 13:56:22.396: I/dalvikvm(1389): Wrote stack traces to '/data/anr/traces.txt'
04-03 13:56:22.936: I/dalvikvm(1389): threadid=3: reacting to signal 3
04-03 13:56:22.976: I/dalvikvm(1389): Wrote stack traces to '/data/anr/traces.txt'

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在appengine项目中老是出现如下错误： java.lang.NoClassDefFoundError: com/google/appengine/tools/enhancer/Enhance Caused by: java.lang.ClassNotFoundException: com.google.appengine.tools.enhancer.Enhance at java.net.URLClassLoader$1.run(Unknown Source) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) at sun.misc.Launcher$AppClassLoader.loadClass(Unknown Source) at java.lang.ClassLoader.loadClass(Unknown Source) Exception in thread "main"

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重新安装eclipse 4.2,3.7 ，重新安装JDK 1.6, 1.7 ，试过了，都出现同样的错误。 或者先构建android app 项目，再生成appengine项目，都出现同样的错误。