错误 "无法实例化活动...在路径上找不到类: DexPathList"

Question

当我尝试在 Eclipse 上构建应用程序时，出现以下错误：

05-20 15:04:51.202: E/AndroidRuntime(1543): FATAL EXCEPTION: main
05-20 15:04:51.202: E/AndroidRuntime(1543): java.lang.RuntimeException: Unable to instantiate activity ComponentInfo{com.devyanlab.testapp/com.devyanlab.testapp.activities.IntroActivity}: java.lang.ClassNotFoundException: Didn't find class "com.devyanlab.testapp.activities.IntroActivity" on path: DexPathList[[zip file "/data/app/com.devyanlab.testapp-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.devyanlab.testapp-1, /system/lib]]
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2137)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.access$600(ActivityThread.java:141)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.os.Handler.dispatchMessage(Handler.java:99)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.os.Looper.loop(Looper.java:137)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.main(ActivityThread.java:5103)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at java.lang.reflect.Method.invokeNative(Native Method)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at java.lang.reflect.Method.invoke(Method.java:525)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at dalvik.system.NativeStart.main(Native Method)
05-20 15:04:51.202: E/AndroidRuntime(1543): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.devyanlab.testapp.activities.IntroActivity" on path: DexPathList[[zip file "/data/app/com.devyanlab.testapp-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.devyanlab.testapp-1, /system/lib]]
05-20 15:04:51.202: E/AndroidRuntime(1543):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:53)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at java.lang.ClassLoader.loadClass(ClassLoader.java:501)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at java.lang.ClassLoader.loadClass(ClassLoader.java:461)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
05-20 15:04:51.202: E/AndroidRuntime(1543):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2128)
05-20 15:04:51.202: E/AndroidRuntime(1543):     ... 11 more

这个应用程序没有错误。我已经尝试了以下方法（除其他方法外）：

• 清理应用程序
• 在“首选项”>“Java构建路径”中检查“Android私有库”
• 检查AndroidManifest.xml上的活动路径
• 多次重启Eclipse
• 重启模拟器（Genymotion）

有什么想法吗？

- jplozano

Answer 1

右键单击您的项目，选择属性。"Properties for"面板将打开。从左侧菜单中进入Java Build Path->Order and Export。从下面的列表中检查您添加到项目中的库或外部jar。最后清理您的项目并运行。

- Ruyonga Dan