DownloadThread.java

import java.io.IOException;
import java.net.HttpURLConnection;
import java.io.RandomAccessFile;
import java.util.concurrent.locks.*;
public class DownloadThread extends Thread{

    Connection conn;
    int startPos;
    int endPos;
    String targetURL;
    //final ReentrantLock lock = new ReentrantLock();

     
    public DownloadThread(Connection conn, int startPos, int endPos, String targetURL) {		
        this.conn = conn;		
        this.startPos = startPos;
        this.endPos = endPos;  
        this.targetURL = targetURL;
    }

    public void run() {               
        System.out.println("�߳�" + getName() + "startPos:" + startPos + "; endPos:" + endPos);
        try {
            RandomAccessFile raf = new RandomAccessFile(targetURL, "rw");   
            byte[] buf = conn.read(startPos, endPos);
            raf.seek(startPos);
            raf.write(buf);
            raf.close();            
        } catch (IOException e) {
            e.printStackTrace();
        }
        System.out.println("�߳�" + this.getName() + "�������.");
    }
}