如何将mp3文件以列表的形式显示出来？

public boolean onOptionsItemSelected(MenuItem item) {
		if (item.getItemId() == UPDATE) {
			updateListView();
		} else if (item.getItemId() == ABOUT) {
			// 用户点击了关于按钮
		}
		return super.onOptionsItemSelected(item);
	}
	private SimpleAdapter buildSimpleAdapter(List<Mp3Info> mp3Infos){
		// 生成一个List对象，并按照SimpleAdapter的标准，将mp3Infos当中的数据添加到List当中去
		List<HashMap<String, String>> list = new ArrayList<HashMap<String, String>>();
		for (Iterator iterator = mp3Infos.iterator(); iterator.hasNext();) {
			Mp3Info mp3Info = (Mp3Info) iterator.next();
			HashMap<String, String> map = new HashMap<String, String>();
			map.put("mp3_name", mp3Info.getMp3Name());
			map.put("mp3_size", mp3Info.getMp3Size());
			list.add(map);
		}
		// 创建一个SimpleAdapter对象
		SimpleAdapter simpleAdapter = new SimpleAdapter(this, list,
				R.layout.mp3info_item, new String[] { "mp3_name", "mp3_size" },
				new int[] { R.id.mp3_name, R.id.mp3_size });
		// 将这个SimpleAdapter对象设置到ListActivity当中
		return simpleAdapter;
	}
	private void updateListView() {
		// 用户点击了更新列表按钮
		// 下载包含所有Mp3基本信息的xml文件
		String xml = downloadXML("http://219.245.78.236:8080/mp3/resources.xml");
		// 对xml文件进行解析，并将解析的结果放置到Mp3Info对象当中，最后将这些Mp3Info对象放置到List当中
		List<Mp3Info> mp3Infos = parse(xml);
		SimpleAdapter simpleAdapter = buildSimpleAdapter(mp3Infos);
		setListAdapter(simpleAdapter);
	}