android - eclipse 安卓 : Didn't find class

Question

我正在执行以下有关使用 Google App Engine 创建 Android 应用程序的教程:https://cloud.google.com/developers/articles/how-to-build-mobile-app-with-app-engine-backend-tutorial

我在 Windows 7 中使用 Eclipse。我到达了运行应用程序以显示从“places.csv”新上传的信息的部分。问题是我收到以下错误:

03-15 17:00:31.137: E/AndroidRuntime(1151): FATAL EXCEPTION: main
03-15 17:00:31.137: E/AndroidRuntime(1151): Process: com.apps.mobileassistant, PID: 1151
03-15 17:00:31.137: E/AndroidRuntime(1151): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.apps.mobileassistant/com.apps.mobileassistant.MainActivity}: java.lang.ClassNotFoundException: Didn't find class "com.apps.mobileassistant.MainActivity" on path: DexPathList[[zip file "/data/app/com.apps.mobileassistant-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.apps.mobileassistant-2, /system/lib]]
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2102)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.app.ActivityThread.access$700(ActivityThread.java:135)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.os.Handler.dispatchMessage(Handler.java:102)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.os.Looper.loop(Looper.java:137)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.app.ActivityThread.main(ActivityThread.java:4998)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at java.lang.reflect.Method.invokeNative(Native Method)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at java.lang.reflect.Method.invoke(Method.java:515)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at dalvik.system.NativeStart.main(Native Method)
03-15 17:00:31.137: E/AndroidRuntime(1151): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.apps.mobileassistant.MainActivity" on path: DexPathList[[zip file "/data/app/com.apps.mobileassistant-2.apk"],nativeLibraryDirectories=[/data/app-lib/com.apps.mobileassistant-2, /system/lib]]
03-15 17:00:31.137: E/AndroidRuntime(1151):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
03-15 17:00:31.137: E/AndroidRuntime(1151):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2093)

MobileAssistant App Manifest.xml

<?xml version="1.0" encoding="utf-8" standalone="no"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" android:versionCode="1" android:versionName="1.0" package="com.apps.mobileassistant">

    <uses-sdk android:minSdkVersion="10" android:targetSdkVersion="19"/>

    <uses-permission android:name="android.permission.INTERNET"/>
   <permission android:name="com.apps.mobileassistant.permission.C2D_MESSAGE" android:protectionLevel="signature"/>

   <uses-permission android:name="com.apps.mobileassistant.permission.C2D_MESSAGE"/>
   <uses-permission android:name="com.google.android.c2dm.permission.RECEIVE"/>
   <uses-permission android:name="android.permission.WAKE_LOCK"/>
   <uses-permission android:name="android.permission.GET_ACCOUNTS"/>
   <uses-permission android:name="android.permission.USE_CREDENTIALS"/>
   <application android:allowBackup="true" android:icon="@drawable/ic_launcher" android:label="@string/app_name" android:theme="@style/AppTheme">
        <activity android:label="@string/app_name" android:name="com.apps.mobileassistant.MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN"/>

                <category android:name="android.intent.category.LAUNCHER"/>
            </intent-filter>
        </activity>
        <service android:name=".GCMIntentService"/>
        <receiver android:name="com.google.android.gcm.GCMBroadcastReceiver" android:permission="com.google.android.c2dm.permission.SEND">
            <intent-filter>
                <action android:name="com.google.android.c2dm.intent.RECEIVE"/>
                <category android:name="com.apps.mobileassistant"/>
            </intent-filter>
            <intent-filter>
                <action android:name="com.google.android.c2dm.intent.REGISTRATION"/>
                <category android:name="com.apps.mobileassistant"/>
            </intent-filter>
        </receiver>

        <activity android:launchMode="singleTop" android:name=".RegisterActivity"/>
</application>

</manifest>

此外，在 Debug模式下，我在 Thread[<1> main] 中收到“找不到源”错误。

有人可以帮我解决这个问题吗？

Answer 1

正如您当前的消息错误告诉您的那样:

ComponentInfo{com.apps.mobileassistant/com.apps.mobileassistant.MainActivity}:
java.lang.ClassNotFoundException: 
Didn't find class "com.apps.mobileassistant.MainActivity" 
on path: DexPathList[[zip file "/data/app/com.apps.mobileassistant-2.apk"],
nativeLibraryDirectories=[/data/app-lib/com.apps.mobileassistant-2

您要么在设置项目和所需库时犯了一些错误，要么只是缺少某些类，要么没有通过导入和类名在代码中通知相应的类。