Android activity crashes when resuming

Question

My app has a button to open a webpage, however when returning to the app it crashes, I am using onPause() and onRestart() methods. Anyone know why it crashes when resuming to the app after closing the webpage?

private void goToUrl(String url) {
    Uri uriUrl = Uri.parse(url);

    Intent launchBrowser = new Intent(Intent.ACTION_VIEW, uriUrl);

    startActivity(launchBrowser);
}

@Override
protected void onPause() {
    super.onPause();

    titleMusic.release();
}

@Override
protected void onRestart() {
    super.onRestart();

    titleMusic.start();
}

logCat stack trace

FATAL EXCEPTION: main
java.lang.RuntimeException: Unable to resume activity java.lang.IllegalStateException
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2836)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2865)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1288)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.os.Handler.dispatchMessage(Handler.java:102)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.os.Looper.loop(Looper.java:212)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.app.ActivityThread.main(ActivityThread.java:5135)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at java.lang.reflect.Method.invokeNative(Native Method)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at java.lang.reflect.Method.invoke(Method.java:515)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:877)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:693)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at dalvik.system.NativeStart.main(Native Method)
04-23 15:49:09.886: E/AndroidRuntime(18310): Caused by: java.lang.IllegalStateException
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.media.MediaPlayer._start(Native Method)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.media.MediaPlayer.start(MediaPlayer.java:1097)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at com.example.hunglikeanandroid.TitleScreen.onRestart(TitleScreen.java:364)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.app.Instrumentation.callActivityOnRestart(Instrumentation.java:1181)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.app.Activity.performRestart(Activity.java:5291)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.app.Activity.performResume(Activity.java:5302)
04-23 15:49:09.886: E/AndroidRuntime(18310):    at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2826)

Answer 1

04-23 15:49:09.886: E/AndroidRuntime(18310): Caused by: java.lang.IllegalStateException 
04-23 15:49:09.886: E/AndroidRuntime(18310): at android.media.MediaPlayer._start(Native Method)

This exception indicates that your media player is in a "wrong" state. Being a state machine, it must be properly initialised , make sure that you properly deal with it's state when going out/coming back to the activity.

For example, in your onPause(), you're releasing MediaPlayer resources, so when you're back, it's not initialised again.