一添加监听器就错误，帮小弟我看看吧，多谢

package wangxin.Activity;import java.io.File;import java.util.ArrayList;import java.util.HashMap;import java.util.Iterator;import java.util.List;import wangxin.file.FileUtils;import wangxin.mode.Mp3;import android.app.Activity;import android.app.AlertDialog;import android.app.ListActivity;import android.content.Context;import android.content.DialogInterface;import android.content.DialogInterface.OnClickListener;import android.content.Intent;import android.net.Uri;import android.os.Bundle;import android.view.Menu;import android.view.MenuItem;import android.view.View;import android.widget.AdapterView;import android.widget.AdapterView.OnItemClickListener;import android.widget.ListView;import android.widget.SimpleAdapter;public class MainActivity extends Activity {    public static final int NEWSONGMENU = 0;    public static final int TOOLMENU = 5;    public static final int ABOUTMENU = 10;    private List<Mp3> mp3Files = null;    public ListView listView = null;    /** Called when the activity is first created. */    @Override    public void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.main);                        listView = (ListView) findViewById(R.id.listView);        listView.setOnItemClickListener(new OnItemClickListener() {            @Override            public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,                    long arg3) {                // TODO Auto-generated method stub                Mp3 mp3 = mp3Files.get(arg2);                Intent intent = new Intent();                intent.putExtra("mp3Song", mp3);                intent.setClass(MainActivity.this, PlayerActivity.class);                startActivity(intent);            }        });    }    @Override    public boolean onCreateOptionsMenu(Menu menu) {        // TODO Auto-generated method stub        menu.add(0, NEWSONGMENU, 0, "新歌");        menu.add(1, TOOLMENU, 5, "工具");        menu.add(3, ABOUTMENU, 10, "关于");        return super.onCreateOptionsMenu(menu);    }    @Override    public boolean onOptionsItemSelected(MenuItem item) {        // TODO Auto-generated method stub        switch (item.getItemId()) {        case NEWSONGMENU:            updateSongs();            break;        case TOOLMENU:            // 现在不实现            break;        case ABOUTMENU:            getAlertDialog(MainActivity.this, "关于",                    "本款小软件由mojia独立完成，灰常不错哦，鼓掌！", "好嘞");            break;        default:            break;        }        return super.onOptionsItemSelected(item);    }    private void updateSongs() {        // TODO Auto-generated method stub        FileUtils fileUtils = new FileUtils();        mp3Files = fileUtils.getMp3Files("mp3");        if (mp3Files != null) {            ArrayList<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();            for (Iterator<Mp3> i = mp3Files.iterator(); i.hasNext();) {                Mp3 mp3 = i.next();                HashMap<String, String> hashMap = new HashMap<String, String>();                hashMap.put("mp3Name", mp3.getName());                list.add(hashMap);            }            SimpleAdapter adapter = new SimpleAdapter(MainActivity.this, list,                    R.layout.songslist, new String[] { "mp3Name" },                    new int[] { R.id.mp3Name });            listView.setAdapter(adapter);        } else {            getAlertDialog(MainActivity.this, "Sorry", "对不起现在还没有歌曲哦,亲", "OK");        }    }    public void getAlertDialog(Context context, String title, String message,            String str_ok) {        // TODO Auto-generated method stub        new AlertDialog.Builder(context).setTitle(title).setMessage(message)                .setPositiveButton(str_ok, new OnClickListener() {                    @Override                    public void onClick(DialogInterface dialog, int which) {                        // TODO Auto-generated method stub                        finish();                    }                }).show();    }}