Java多线程下载

 

同时下载多个文件，不过单文件没有多线程的下载并且没有断点续传功能，继续完善:

package com.util.file;

public class Files {

    /***
     * 获取应用程序的根目录
     * @return 应用程序根目录
     */
    public static String getSysPath(){
	return  System.getProperty("user.dir"); 
    }

    
}

package com.core.crawl;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;

import com.core.http.Http;

public class WebSpider implements Runnable{
    
    private Http http = new Http();

    private String webAddress = "";
    private String destFile = "";
    
    public void setWebAddress(String webAddress){
	this.webAddress = webAddress;
    }
    
    public void setDestFile (String destFile){
	this.destFile = destFile;
    }
    
    public boolean download() throws IOException, InterruptedException {

	HttpURLConnection httpConn = null;

	try {
	    URL url = new URL(webAddress);
	  
	    httpConn = (HttpURLConnection) url.openConnection();
	    httpConn.setRequestMethod("GET");
	    httpConn.setRequestProperty("User-Agent", "Mozilla/5.0 (Windows; U; Windows NT 5.1; zh-CN; rv:1.8.1.14) Gecko/20080404 Firefox/2.0.0.14");
	    InputStream in = httpConn.getInputStream();
	    String fileType = http.fileType(httpConn.getContentType());
	    System.out.println(fileType);
	    FileOutputStream out = new FileOutputStream(new File(destFile + fileType));
	    int chByte = in.read();
	    while (chByte != -1) {
		out.write(chByte);
		//System.out.println(chByte);
		chByte = in.read();
	    }
	} catch (Exception ex) {
	    System.out.println(ex.toString());
	} finally {
	    httpConn.disconnect();
	}
	return true;
    }

    public void run() {
	try {
	    //System.out.println(Thread.currentThread().getName());
	    download();    
	} catch (IOException e) {
	    e.printStackTrace();
	} catch (InterruptedException e) {
	    e.printStackTrace();
	}
    }
}

package com.core.crawl;

import java.io.IOException;

import com.util.file.Files;

public class Crawl {

    /**
     * @param args
     * @throws IOException 
     * @throws InterruptedException 
     */
    public static void main(String[] args) throws IOException, InterruptedException {

	long begin = System.currentTimeMillis();
	WebSpider spider2 = new WebSpider();
	WebSpider spider1 = new WebSpider();
	spider1.setWebAddress("http://www.163.com");
	spider1.setDestFile(Files.getSysPath() + "/"+"spider1.");
	
	spider2.setWebAddress("http://blog.csdn.net/longronglin");
	spider2.setDestFile(Files.getSysPath() + "/"+"spider2.");

	Thread t1 = new Thread(spider1);
	Thread t2 = new Thread(spider2);
	t1.start();
	t2.start();

	t1.join();
	t2.join();
	
	System.out.println("the end");
	System.out.println(System.currentTimeMillis() - begin);
    }
    


}
 
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