关于mediaplay遇到一些问题，急求

代码如下
package org.lxh.demo;

import java.io.IOException;

import android.app.Activity;
import android.content.Intent;
import android.media.AudioManager;
import android.media.MediaPlayer;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.Window;
import android.view.WindowManager;
import android.widget.ImageButton;

public class PlayVideoActivity extends Activity {
private ImageButton play = null;
private ImageButton stop = null;
private ImageButton back = null;
private MediaPlayer media = null;
private SurfaceView sufaceView = null;
private SurfaceHolder surfaceHolder = null;
private String filepath = null;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    super.requestWindowFeature(Window.FEATURE_NO_TITLE); // 不显示标题
    super.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    super.getWindow().addFlags(
            WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON); // 高亮的风格显示
    super.setContentView(R.layout.play);

    this.filepath = super.getIntent().getStringExtra("filepath") ;

    this.play = (ImageButton) super.findViewById(R.id.play);
    this.stop = (ImageButton) super.findViewById(R.id.stop);
    this.back = (ImageButton) super.findViewById(R.id.back);
    this.sufaceView = (SurfaceView) super.findViewById(R.id.surfaceView) ;
    this.surfaceHolder = this.sufaceView.getHolder() ;
    this.surfaceHolder.setType(SurfaceHolder.SURFACE_TYPE_PUSH_BUFFERS) ;
    this.media =new MediaPlayer() ;
    this.media.reset() ;
    try {
        this.media.setDataSource(this.filepath) ;
    } catch (Exception e) {
    }

    this.play.setOnClickListener(new PlayOnClickListenerImpl());
    this.stop.setOnClickListener(new StopOnClickListenerImpl());
    this.back.setOnClickListener(new BackOnClickListenerImpl());
}

private class PlayOnClickListenerImpl implements OnClickListener {
    @Override
    public void onClick(View v) {
        PlayVideoActivity.this.media.setAudioStreamType(AudioManager.STREAM_MUSIC) ;
        PlayVideoActivity.this.media.setDisplay(PlayVideoActivity.this.surfaceHolder) ;
        try {
            PlayVideoActivity.this.media.prepare() ;
            PlayVideoActivity.this.media.start() ;
        } catch (Exception e) {
        }
    }
}

private class StopOnClickListenerImpl implements OnClickListener {
    @Override
    public void onClick(View v) {
        PlayVideoActivity.this.media.stop() ;
    }
}

private class BackOnClickListenerImpl implements OnClickListener {
    @Override
    public void onClick(View v) {
        Intent it = new Intent(PlayVideoActivity.this, BroswerActivity.class);
        PlayVideoActivity.this.startActivity(it);
    }
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if(keyCode == KeyEvent.KEYCODE_BACK) {
        this.media.stop() ;
        this.media.release() ;
        super.finish() ;
    }
    return false ;
}

}
编译的时候报错为
图片说明

        PlayVideoActivity.this.media.prepare() ;
        PlayVideoActivity.this.media.start() ;