Unfortunately app has stopped working android emulator

Question

I tried to run my app but I got a message "Unfortunately app has stopped". my logcat is below.The problem has been resolved

02-02 07:54:20.224: I/Process(1820): Sending signal. PID: 1820 SIG: 9
02-02 07:54:24.184: D/AndroidRuntime(1853): Shutting down VM
02-02 07:54:24.204: W/dalvikvm(1853): threadid=1: thread exiting with uncaught exception  (group=0xb0cd1b08)
02-02 07:54:24.244: E/AndroidRuntime(1853): FATAL EXCEPTION: main
02-02 07:54:24.244: E/AndroidRuntime(1853): Process: com.example.judoapp, PID: 1853
02-02 07:54:24.244: E/AndroidRuntime(1853): java.lang.RuntimeException: Unable to   instantiate activity ComponentInfo{com.example.judoapp/com.example.judoapp.MainActivity}:    java.lang.ClassNotFoundException: Didn't find class "com.example.judoapp.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.judoapp-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.judoapp-1, /system/lib]]
02-02 07:54:24.244: E/AndroidRuntime(1853):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2102)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2226)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at android.app.ActivityThread.access$700(ActivityThread.java:135)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at  android.app.ActivityThread$H.handleMessage(ActivityThread.java:1397)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at android.os.Handler.dispatchMessage(Handler.java:102)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at android.os.Looper.loop(Looper.java:137)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at android.app.ActivityThread.main(ActivityThread.java:4998)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at java.lang.reflect.Method.invokeNative(Native Method)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at java.lang.reflect.Method.invoke(Method.java:515)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at dalvik.system.NativeStart.main(Native Method)
02-02 07:54:24.244: E/AndroidRuntime(1853): Caused by: java.lang.ClassNotFoundException: Didn't find class "com.example.judoapp.MainActivity" on path: DexPathList[[zip file "/data/app/com.example.judoapp-1.apk"],nativeLibraryDirectories=[/data/app-lib/com.example.judoapp-1, /system/lib]]
02-02 07:54:24.244: E/AndroidRuntime(1853):     at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:56)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at java.lang.ClassLoader.loadClass(ClassLoader.java:497)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at java.lang.ClassLoader.loadClass(ClassLoader.java:457)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at android.app.Instrumentation.newActivity(Instrumentation.java:1061)
02-02 07:54:24.244: E/AndroidRuntime(1853):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2093)
02-02 07:54:24.244: E/AndroidRuntime(1853):     ... 11 more
02-02 07:54:27.434: I/Process(1853): Sending signal. PID: 1853 SIG: 9

Answer 1

android:name="com.example.judoapp.MainActivity"

It's looking for the class MainActivity in com.example.judoapp . Either add it, or change that line to the real package of the Activity .

Answer 2

system didn't find MainActivity

check your MainActivity package name.

look at error on logcat:

Didn't find class "com.example.judoapp.MainActivity"

go to src folder and check package name for MainActivity

good luck