我在libs文件夹中添加了一个外部jar，我可以从代码中看到这个方法，不会出现任何错误。当我编译应用程序启动没有问题但是当我按下使用外部jar方法的botton应用程序崩溃时，这就是Logcat：
05-15 13:37:49.782: E/dalvikvm(17475): Could not find class 'es.jerogaren.funciones.aleatorio1', referenced from method com.example.ejemplo.FullscreenActivity$5.onClick
05-15 13:37:49.782: W/dalvikvm(17475): VFY: unable to resolve new-instance 1034 (Les/jerogaren/funciones/aleatorio1;) in Lcom/example/ejemplo/FullscreenActivity$5;
05-15 13:37:49.782: D/dalvikvm(17475): VFY: replacing opcode 0x22 at 0x0007
05-15 13:37:49.782: D/dalvikvm(17475): DexOpt: unable to opt direct call 0x2125 at 0x09 in Lcom/example/ejemplo/FullscreenActivity$5;.onClick
05-15 13:37:49.812: I/Adreno-EGL(17475): <qeglDrvAPI_eglInitialize:320>: EGL 1.4 QUALCOMM Build: I0404c4692afb8623f95c43aeb6d5e13ed4b30ddbDate: 11/06/13
05-15 13:37:49.842: D/OpenGLRenderer(17475): Enabling debug mode 0
05-15 13:37:51.624: W/dalvikvm(17475): threadid=1: thread exiting with uncaught exception (group=0x415e4ba8)
05-15 13:37:51.634: E/AndroidRuntime(17475): FATAL EXCEPTION: main
05-15 13:37:51.634: E/AndroidRuntime(17475): Process: com.example.ejemplo, PID: 17475
05-15 13:37:51.634: E/AndroidRuntime(17475): java.lang.NoClassDefFoundError: es.jerogaren.funciones.aleatorio1
05-15 13:37:51.634: E/AndroidRuntime(17475): at com.example.ejemplo.FullscreenActivity$5.onClick(FullscreenActivity.java:137)
05-15 13:37:51.634: E/AndroidRuntime(17475): at android.view.View.performClick(View.java:4438)
05-15 13:37:51.634: E/AndroidRuntime(17475): at android.os.Handler.handleCallback(Handler.java:733)
05-15 13:37:51.634: E/AndroidRuntime(17475): at java.lang.reflect.Method.invoke(Method.java:515)
05-15 13:37:51.634: E/AndroidRuntime(17475): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:779)
05-15 13:37:51.634: E/AndroidRuntime(17475): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:595)
05-15 13:37:51.634: E/AndroidRuntime(17475): at dalvik.system.NativeStart.main(Native Method)
05-15 13:37:51.634: E/AndroidRuntime(17475): at android.app.ActivityThread.main(ActivityThread.java:5017)
05-15 13:37:51.634: E/AndroidRuntime(17475): at java.lang.reflect.Method.invokeNative(Native Method)
我正在使用Windows 8和Nexus 4，
我有什么问题吗？