ClassNotFoundException after ADT update

问题:

I\'ve recently updated Android SDK & Eclipse ADT plugin to latest version. Now when i try to run a pre-existing Android project, the LogCat shows a ClassNotFoundException.

I tried to create a new device but the problem still exists.

Manifest

<?xml version=\"1.0\" encoding=\"utf-8\"?>
<manifest xmlns:android=\"http://schemas.android.com/apk/res/android\"
package=\"com.example.myapp\"
android:versionCode=\"1\"
android:versionName=\"1.0\" >

<uses-sdk
    android:minSdkVersion=\"8\"
    android:targetSdkVersion=\"17\" />

<uses-permission android:name=\"android.permission.INTERNET\" />
<uses-permission android:name=\"android.permission.WRITE_EXTERNAL_STORAGE\" />
<uses-permission android:name=\"android.permission.ACCESS_NETWORK_STATE\" />

<application
    android:allowBackup=\"true\"
    android:icon=\"@drawable/ic_launcher\"
    android:label=\"@string/app_name\"
    android:theme=\"@style/AppTheme\" >
    <activity
        android:name=\"com.example.myapp.MainActivity\"
        android:label=\"@string/app_name\"
        android:windowSoftInputMode=\"stateHidden\" >
        <intent-filter>
            <action android:name=\"android.intent.action.MAIN\" />

            <category android:name=\"android.intent.category.LAUNCHER\" />
        </intent-filter>
    </activity>
</application>

LogCat

05-17 13:09:56.357: E/AndroidRuntime(969): FATAL EXCEPTION: main
05-17 13:09:56.357: E/AndroidRuntime(969): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.example.myapp/com.example.myapp.MainActivity}: java.lang.ClassNotFoundException: Didn\'t find class \"com.example.myapp.MainActivity\" on path: /data/app/com.example.myapp-1.apk
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2106)
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2230)
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1234)
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.os.Handler.dispatchMessage(Handler.java:99)
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.os.Looper.loop(Looper.java:137)
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.app.ActivityThread.main(ActivityThread.java:5041)
05-17 13:09:56.357: E/AndroidRuntime(969):  at java.lang.reflect.Method.invokeNative(Native Method)
05-17 13:09:56.357: E/AndroidRuntime(969):  at java.lang.reflect.Method.invoke(Method.java:511)
05-17 13:09:56.357: E/AndroidRuntime(969):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-17 13:09:56.357: E/AndroidRuntime(969):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-17 13:09:56.357: E/AndroidRuntime(969):  at dalvik.system.NativeStart.main(Native Method)
05-17 13:09:56.357: E/AndroidRuntime(969): Caused by: java.lang.ClassNotFoundException: Didn\'t find class \"com.example.myapp.MainActivity\" on path: /data/app/com.example.myapp-1.apk
05-17 13:09:56.357: E/AndroidRuntime(969):  at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:65)
05-17 13:09:56.357: E/AndroidRuntime(969):  at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-17 13:09:56.357: E/AndroidRuntime(969):  at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.app.Instrumentation.newActivity(Instrumentation.java:1054)
05-17 13:09:56.357: E/AndroidRuntime(969):  at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2097)
05-17 13:09:56.357: E/AndroidRuntime(969):  ... 11 more

I noticed that the new APK file is called myapp-1.apk, while it was usually called myapp.apk. Can someone tell me how to fix?

回答1:

Try going to Project -> Properties -> Java Build Path -> Order & Export and ensure Android Private Libraries are checked for your project and for all other library projects you are using. Clean all projects afterwards and see what happens.

回答2:

I know I\'m very late to post a reply here. The workaround mentioned by Krauxe didn\'t help me. My project has two library projects and two jars. I found a solution posted by \"laaptu\" in the page Libraries do not get added to APK anymore after upgrade to ADT 22.

回答3:

I have the Eclipse ADT bundle and additional to the @Krauxe\'s answer, updating the Eclipse .project file as below worked for me:

<?xml version=\"1.0\" encoding=\"UTF-8\"?>
<projectDescription>
    <name>RedbeaconPro</name>
    <comment></comment>
    <projects>
    </projects>
    <buildSpec>
        <buildCommand>
            <name>com.android.ide.eclipse.adt.ResourceManagerBuilder</name>
            <arguments>
            </arguments>
        </buildCommand>
        <buildCommand>
            <name>com.android.ide.eclipse.adt.PreCompilerBuilder</name>
            <arguments>
            </arguments>
        </buildCommand>
        <buildCommand>
            <name>org.eclipse.jdt.core.javabuilder</name>
            <arguments>
            </arguments>
        </buildCommand>
        <buildCommand>
            <name>com.android.ide.eclipse.adt.ApkBuilder</name>
            <arguments>
            </arguments>
        </buildCommand>
    </buildSpec>
    <natures>
        <nature>com.android.ide.eclipse.adt.AndroidNature</nature>
        <nature>org.eclipse.jdt.core.javanature</nature>
    </natures>
</projectDescription>

回答4:

If you are using Maven plugin in your project as well, \"Maven -> Maven Update...\" may cause the same problem that ClassNotFoundException. As you know, the default classes output folder should be /bin/classes which is specified in .classpath file and Eclipse Build Path. But once you do \"Maven->Maven Update...\", the output folder would be set as \"target/classes\". You can find it(output=\"target/classes\") in your .classpath file.

.classpath file:

...    
<classpath>
            <classpathentry kind=\"src\" path=\"gen\"/>
            <classpathentry kind=\"src\" output=\"target/classes\" path=\"src/main/java\">
...

How to resolve this problem, please explicitly specify the classes output folder as \"bin/classes\" in pom.xml file.

pom.xml file:

...
<build>
            <sourceDirectory>src/main/java</sourceDirectory>
            <outputDirectory>bin/classes</outputDirectory>
...