NullPointerException : println needs a message in android

in my media player i play a song from sdcard. it shows error as NullPointerException : println needs a message e in android. i tried long time but i do not know the reason .please assist me.

code:

    try {
        mediaPlayer = new  MediaPlayer();
        mediaPlayer.setDataSource("/sdcard/t1.mp3");
        seek.setMax(mediaPlayer.getDuration());
        mediaPlayer.prepare();
        mediaPl开发者_JS百科ayer.start();
        mediaPlayer.setOnCompletionListener(this);          
    }
    catch(Exception ex){
        Log.e("sdcard-err2:",ex.getMessage());  //  null pointer exception : println needs a message 
    }  

Log cat:

     05-16 19:27:54.491: ERROR/AndroidRuntime(6889): Caused by: java.lang.NullPointerException: println needs a message
     05-16 19:27:54.491: ERROR/AndroidRuntime(6889):     at android.util.Log.println(Native Method)
     05-16 19:27:54.491: ERROR/AndroidRuntime(6889):     at android.util.Log.e(Log.java:208)
     05-16 19:27:54.491: ERROR/AndroidRuntime(6889):     at com.seek.bar.media3.onCreate(media3.java:43)
     05-16 19:27:54.491: ERROR/AndroidRuntime(6889):     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
     05-16 19:27:54.491: ERROR/AndroidRuntime(6889):     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2459)
     05-16 19:27:54.491: ERROR/AndroidRuntime(6889):     ... 11 more

For anyone else that gets this, try replacing the lone method call or variable name with "" + varName.

For example,

Log.d("LOGCAT", getErrorMsg());

becomes

Log.d("LOGCAT", "" + getErrorMsg());

In the catch, use:

String err = (ex.getMessage()==null)?"SD Card failed":ex.getMessage();
Log.e("sdcard-err2:", err);

Passing null to the second argument of a Log logging function throws that error, regardless of the source.

Maybe there's simply no message attached in exception you're catching. Try ex.printStackTrace(); instead. Hope this helps.

Another way that can to use is with Log.getStackTraceString(e), example:

Log.e(TAG, Log.getStackTraceString(e));

You can read more about that in Android Documentation.

"println needs a megssage" was a very confusing message to receive (at least for me) when not using the println(...) method at all!!!

In my case and for that matter in all cases that generate this type of error there is a constellation you have to watch out for:

try{
...
}catch(..){
  // in here there is a reference to the Logger
}

Now the problem is that in your try{...} block you are using an uninitialized reference or some old instance that now points to null

Setup a break-point at the very beginning of your try block and debug your code step by step, you will find that at some point the code will try to access methods of some object that is null.

In this case I tend to blame your seek object !

Regards.

My answer is useful only when you are 100% sure you have tried all the up and down answers related to Log.

For me it was not at all about logs, @Vero's answer helped me to narrow down my problem.

One of my variable inside try catch block was null at some point of time in execution and hence I was getting this exception, to resolve it I just checked null for all the variables inside try catch block and that is it.

Though you should check why that variable is getting null but that is not part of this issue I guess ;)

Resolved.