I'm new to android development field and was making a MusicApp. Getting stuck with the following :     private OnClickListener onButtonClick = new OnClickListener() {
          //  @Override
            public void OnClick(View v) {
                switch (v.getId()) {
                    case R.id.play: {
                        if (player.isPlaying()) {
                            handler.removeCallbacks(updatePositionRunnable);
                            player.pause();
                            playButton.setImageResource(android.R.drawable.ic_media_play);
                        } else {
                            if (isStarted) {
                                player.start();
                                playButton.setImageResource(android.R.drawable.ic_media_pause);
    
                                updatePosition();
                            } else {
                                startPlay(currentFile);
                            }
                        }
                        break;
                    }
                    case R.id.next: {
                        int seekto = player.getCurrentPosition() + STEP_VALUE;
    
                        if (seekto > player.getDuration())
                            seekto = player.getDuration();
                        player.pause();
                        ;
                        player.seekTo(seekto);
                        player.start();
    
                        break;
                    }
                    case R.id.prev: {
                        int seekto = player.getCurrentPosition() - STEP_VALUE;
                        if (seekto < 0)
                            seekto = 0;
    
                        player.pause();
                        player.seekTo(seekto);
                        player.start();
    
                        break;
                    }
    
                }
    
            }
    
        };
    
        private MediaPlayer.OnCompletionListener onCompletion = new MediaPlayer.OnCompletionListener() {
    
            @Override
            public void onCompletion(MediaPlayer mp) {
                stopPlay();
            }
        };
    
        private MediaPlayer.OnErrorListener onError = new MediaPlayer.OnErrorListener() {
           // @Override
            public boolean OnError(MediaPlayer mp, int what, int extra) {
                return false;
            }
        };
    
        private SeekBar.OnSeekBarChangeListener seekBarChanged = new SeekBar.OnSeekBarChangeListener() {
            //@Override
            public void OnStopTrackingTouch(SeekBar seekBar) {
                isMoveingSeekBar = false;
            }
    
            //@Override
            public void OnStartTrackingTouch(SeekBar seekBar) {
                isMoveingSeekBar = true;
            }
    
            //@Override
            public void OnProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
                if (isMoveingSeekBar)
                {
                    player.seekTo(progress);
                Log.i("OnSeekBarChangedListener", "OnProgressChanged");
                }
            }
        };
    }






I'm getting this after gradle build.

Error:(189, 67) error: <anonymous com.example.shubham.hymnattune.MainActivity$2> is not abstract and does not override abstract method onClick(View) in OnClickListener

Error:(248, 85) error: <anonymous com.example.shubham.hymnattune.MainActivity$4> is not abstract and does not override abstract method onError(MediaPlayer,int,int) in OnErrorListener

Error:(255, 100) error: <anonymous com.example.shubham.hymnattune.MainActivity$5> is not abstract and does not override abstract method onStopTrackingTouch(SeekBar) in OnSeekBarChangeListener

Error:Execution failed for task ':app:compileDebugJavaWithJavac'.
> Compilation failed; see the compiler error output for details.


Please Help.
Thanks in Advance.