Android&String.index()

package com.zachary.xmlresolve;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.widget.TextView;

public class MainActivity extends Activity {
    private TextView myTextView;
    private String xml;
    private boolean finish = false;
    final static String TAG = "LOGCAT";
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //String xmlStr = "![CDATA[你好啊 。。。   ]]";
        myTextView = (TextView)findViewById(R.id.myTextView);
        //xml = getMidString(xmlStr, "![CDATA[", "]]");
        //myTextView.setText(xml);
        //System.out.println(xml);
        String urlStr ="http://box.zhangmen.baidu.com/x?op=12&count=1&title=%E6%80%92%E6%94%BE%E7%9A%84%E7%94%9F%E5%91%BD$$%E6%B1%AA%E5%B3%B0$$$$";
        new downloadThread(urlStr).start();
        while(!finish) ;
        myTextView.setText(xml);
        finish = false;
        String count = getMidString(xml, "<count>", "</count>");
        String encode, decode, lrcid, musicUrlStr, lrcUrlStr;
        if(count != "0")
        { 
            encode = getMidString(xml, "<encode><![CDATA[", "]]></encode>");
            decode = getMidString(xml, "<decode><![CDATA[", "]]></decode>");
            lrcid = getMidString(xml, "<lrcid>", "</lrcid>");
            musicUrlStr = getMusicUrlStr(encode, decode);
            lrcUrlStr = getLrcUrlStr(lrcid);
            myTextView.setText(musicUrlStr + "\n******\n" + lrcUrlStr);
        }
        else
            myTextView.setText("Not found");
    }
    public String getMidString(String inputstring, String left,String right){
        int k0 = inputstring.indexOf(left);
        if(k0<0){
        return "";
        }
        int k1= k0+left.length();
        int k2 = inputstring.indexOf(right,k1);
        if(k2<=k1){
        return "";
        }
        String return_v = inputstring.substring(k1,k2);
        return return_v;
        }
    
    public String getMusicUrlStr(String encode, String decode){
        int k0 = encode.lastIndexOf("/");
        if(k0<0)
            return "";
        String musicUrlStr = encode.substring(0, k0+1) + decode;
        return musicUrlStr;
    }
    
    public String getLrcUrlStr(String lrcid){
        if(lrcid == "0")
            return "";
        String lrcUrlStr = "http://box.zhangmen.baidu.com/bdlrc/";
        String mid = lrcid.substring(0, lrcid.length()-2);
        return lrcUrlStr + mid + "/" + lrcid + ".lrc";
    }
    class downloadThread extends Thread {
        String urlStr;
        downloadThread(String urlStr){
            this.urlStr = urlStr;
            Log.i(TAG, "Creat the Thread");
        }

        @Override
        public void run() {
            StringBuffer sb = new StringBuffer();
            String line = null;
            BufferedReader buffer = null;
            try {
                URL url = new URL(urlStr);
                HttpURLConnection urlConn = (HttpURLConnection)url.openConnection();
                buffer = new BufferedReader(new InputStreamReader(urlConn.getInputStream()));
                while((line = buffer.readLine())!=null)
                    sb.append(line);
            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }finally{
                try {
                    buffer.close();
                    xml = sb.toString();
                    finish = true;
                    //myTextView.setText(xml);
                    System.out.println(xml);
                    Log.i(TAG, xml);
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            
        }
        
        
    }
    
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

}