关于安卓开发的一个下载问题

Question

//这里是一个片段源代码，下面还有一张出错的日志，希望好心的大神解答一下，这个问题搞了一天还没有结果；
package mars.mp3player.mp3player;

import java.io.StringReader;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;

import javax.xml.parsers.SAXParserFactory;

import org.xml.sax.InputSource;
import org.xml.sax.XMLReader;

import mars.download.HttpDownloader;
import mars.model.Mp3Info;
import mars.mp3player.service.DownloadService;
import mars.xml.Mp3ListContentHandle;
import android.os.Bundle;
import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.SimpleAdapter;

public class Mp3ListActivity extends ListActivity {

private static final int UPDATE =1;
private static final int ABOUT =2;
private List<Mp3Info> mp3Infos =null;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.remote_mp3_list);
    updateListView();
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
   // getMenuInflater().inflate(R.menu.mp3_list, menu);
    menu.add(0, UPDATE, 1, R.string.mp3list_update);
    menu.add(0, ABOUT, 2, R.string.mp3list_about);
    return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // TODO Auto-generated method stub
    if (item.getItemId()==UPDATE) {
        //用户点击了更新按钮
        //下载包含所有MP3 基本信息的xml文件中
        System.out.println("选择的类别"+item.getItemId());
    updateListView();//有错误
    }
    else if (item.getItemId()==ABOUT)
    {
        //用户点击了关于按钮
    }
    return super.onOptionsItemSelected(item);
}
private String downloadXMl(String urlStr){
    HttpDownloader httpDownloader = new HttpDownloader();
    String result =httpDownloader.download(urlStr);//有错误
    return result;
}
private List<Mp3Info> parse(String xmlStr)
{
   SAXParserFactory saxParserFactory =SAXParserFactory.newInstance();
   List<Mp3Info> infos=null;
   try {

       XMLReader xmlReader =saxParserFactory.newSAXParser().getXMLReader();
       infos =new ArrayList<Mp3Info>();
       Mp3ListContentHandle mp3ListContentHandle =new Mp3ListContentHandle(infos);
       xmlReader.setContentHandler(mp3ListContentHandle);
       xmlReader.parse(new InputSource(new StringReader(xmlStr)));
       for( Iterator iterator =infos.iterator();iterator.hasNext();)
       {
           Mp3Info mp3Info =(Mp3Info) iterator.next();
           System.out.println(mp3Info);
       }
} catch (Exception e) {
    // TODO: handle exception
}
    return infos;
} 
private void updateListView()
{
    String xml =downloadXMl("http://192.168.191.1:8080/mp3/resources.xml");//有错误
    System.out.println("xml---->"+xml);//这里没有下载到！
    //parse(xml);
    //对xMl文件进行解析，并将解的的结果放到MP3info当中的list中去
     mp3Infos =parse(xml);
    SimpleAdapter simpleAdapter=buildSimpleAdapter(mp3Infos);
    setListAdapter(simpleAdapter);
} 
private SimpleAdapter buildSimpleAdapter(List<Mp3Info> mp3Infos){
    //生成一个额list对象，并按照simple的标准，将MP3info当中的数据添加的list当中
            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_id",mp3Info.getId());
                map.put("mp3_name",mp3Info.getMp3Name());  
                list.add(map);
            }
            //创建一个adapter对象
            SimpleAdapter simpleAdapter = new SimpleAdapter(this, list, R.layout.mp3info_item, new String[]{"mp3_id","mp3_name"},new int[]{R.id.mp3_id,R.id.mp3_name});
            return simpleAdapter;
}


@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    // TODO Auto-generated method stub
    Mp3Info mp3Info = mp3Infos.get(position);
    Intent intent  = new Intent ();
    //将MP3info对象放入intent中
    intent.putExtra("mp3info", mp3Info);
    intent.setClass(this, DownloadService.class);
    //启动service
    startService(intent);
    super.onListItemClick(l, v, position, id);

}

}

Answer 1

http://dampce032.iteye.com/blog/975642
另外检查服务器本身是否有限制