使用带有 Android SDK 的 Mac OSX 10.8.3 和 Eclipse ADT 来遵循 Google Cloud Platform 教程 ( https://developers.google.com/cloud/samples/mbs/getting_started )。当客户端应用程序部署到 Nexus 4 (4.2.2) 时，应用程序启动，但失败并显示错误“不幸的是，CloudBackendAndroidClient 已停止。” 在 Eclipse LogCat 中，我看到下面复制的错误。有什么提示吗？正如教程所提到的，这段代码应该只适用于正在编辑的 Consts.java 文件中的一行。
06-03 21:20:39.225: E/AndroidRuntime(7896): FATAL EXCEPTION: main
06-03 21:20:39.225: E/AndroidRuntime(7896): java.lang.NoClassDefFoundError: com.google.cloud.backend.android.GCMIntentService
06-03 21:20:39.225: E/AndroidRuntime(7896): at com.google.cloud.backend.android.CloudBackendAsync.<init>(CloudBackendAsync.java:71)
06-03 21:20:39.225: E/AndroidRuntime(7896): at com.google.cloud.backend.android.CloudBackendMessaging.<init>(CloudBackendMessaging.java:47)
06-03 21:20:39.225: E/AndroidRuntime(7896): at com.google.cloud.backend.android.CloudBackendActivity.onCreate(CloudBackendActivity.java:75)
06-03 21:20:39.225: E/AndroidRuntime(7896): at com.google.cloud.backend.android.sample.guestbook.GuestbookActivity.onCreate(GuestbookActivity.java:60)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.app.Activity.performCreate(Activity.java:5104)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1080)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2144)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.app.ActivityThread.access$600(ActivityThread.java:141)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.os.Handler.dispatchMessage(Handler.java:99)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.os.Looper.loop(Looper.java:137)
06-03 21:20:39.225: E/AndroidRuntime(7896): at android.app.ActivityThread.main(ActivityThread.java:5041)
06-03 21:20:39.225: E/AndroidRuntime(7896): at java.lang.reflect.Method.invokeNative(Native Method)
06-03 21:20:39.225: E/AndroidRuntime(7896): at java.lang.reflect.Method.invoke(Method.java:511)
06-03 21:20:39.225: E/AndroidRuntime(7896): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
06-03 21:20:39.225: E/AndroidRuntime(7896): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
06-03 21:20:39.225: E/AndroidRuntime(7896): at dalvik.system.NativeStart.main(Native Method)