作业下载图片

最新推荐文章于 2025-05-06 14:26:22 发布

原创最新推荐文章于 2025-05-06 14:26:22 发布 · 383 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#java

Java_Train 专栏收录该内容

21 篇文章

订阅专栏

本文详细介绍了如何使用HttpURLConnection和HttpClient在Java中实现多线程图片下载，包括线程1利用HttpURLConnection下载图片和线程2利用HttpClient下载图片的实现过程，同时提供了测试代码。

下载图片要求：

分别用HttpURLConnection 和 HttpClient对两个图片进行下载，利用多线程，接口回调的方式。

线程1: 利用HttpURLConnection线程进行下载

import java.io.BufferedInputStream;
import java.io.ByteArrayOutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
 
/**
 * 这个线程利用HttpURLConnection负责下载
 * @author Mixm
 * @date 2015年10月8日 下午11:38:44
 */
public class HUCDownloadThread extends Thread {
 
	private String path = null;
	CallBack01 cb = null;
 
	public HUCDownloadThread(String path, CallBack01 cb) {
		this.path = path;
		this.cb = cb;
	}
 
	@Override
	public void run() {
		URL url = null;
		HttpURLConnection conn = null;
 
		BufferedInputStream bis = null;
		ByteArrayOutputStream baos = null;
 
		try {
			url = new URL(path);
			conn = (HttpURLConnection) url.openConnection();
 
			if (conn.getResponseCode() == 200) {
				bis = new BufferedInputStream(conn.getInputStream());
				baos = new ByteArrayOutputStream();
				
				byte[] b = new byte[1024];
				int len = 0;
				
				while((len = bis.read(b)) != -1){
					baos.write(b, 0, len);
					System.out.println(getName() + "haha 在下载");
				}
				baos.flush();
				cb.success(baos.toByteArray());
 
			} else {
				System.out.println("臣妾做不到啊");
			}
 
		} catch (Exception e) {
			e.printStackTrace();
		} finally {
			try {
				bis.close();
				baos.close();
				conn.disconnect();
			} catch (Exception e2) {
				e2.printStackTrace();
			}
		}
	}
}
 
interface CallBack01 {
	void success(byte[] b);
}

线程2: 利用HttpClient进行下载:

import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
 
import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.HttpClient;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.DefaultHttpClient;
 
/**
 * 这个线程利用HttpClient进行下载
 * @author Mixm
 * @date 2015年10月8日 下午11:39:52
 */
public class HCDownloadThread extends Thread{
	private String uriPath = null;
	private String savePath = null;
	private CallBack2 cb = null;
	
	
	public HCDownloadThread(String uriPath, String savePath, CallBack2 cb) {
		super();
		this.uriPath = uriPath;
		this.savePath = savePath;
		this.cb = cb;
	}
	
	@Override
	public void run() {
		try {
			//创建httpclient链接对象
			HttpClient client = new DefaultHttpClient();
			//创建请求方式
			HttpGet get = new HttpGet(uriPath);
			
			//得到返回
			HttpResponse response = client.execute(get);
			
			if (response.getStatusLine().getStatusCode() != -1) {
				HttpEntity hEntity = response.getEntity();
				BufferedInputStream bis = new BufferedInputStream(hEntity.getContent());
				
				BufferedOutputStream bos = new BufferedOutputStream(new FileOutputStream(savePath));
				
				byte[] b = new byte[1024];
				int len = 0;
				while ((len = bis.read(b)) != -1) {
					System.out.println(getName() + "我在下载");
					bos.write(b, 0, len);
				}
				bos.flush();
				cb.success();
				
				bos.close();
				bis.close();
				
				
			} else {
 
			}
			
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
}
 
interface CallBack2{
	//这里就不传递数组了
	void success();
}

测试代码:

import java.io.BufferedOutputStream;
import java.io.FileOutputStream;
import java.io.IOException;
 
public class TestHttpClientDemo01 {
 
	public static void main(String[] args) {
		String path = "http://img0.bdstatic.com/img/image/6446027056db8afa73b23eaf953dadde1410240902.jpg";
		new HUCDownloadThread(path, new CallBack01() {
 
			@Override
			public void success(byte[] b) {
				// 传过来的是数组 哥哥就写如文件中去
				BufferedOutputStream bos = null;
				try {
					bos = new BufferedOutputStream(new FileOutputStream(
							"hk1.jpg"));
					bos.write(b);
					bos.flush();
					bos.close();
				} catch (IOException e) {
					e.printStackTrace();
				}
 
			}
		}).start();
 
		// 第二个线程下载
		String uriPath = "http://img0.bdstatic.com/img/image/ca3accc6b9c7736fc3f90ca6c407df341409737570.jpg";
		String savePath = "hk2.jpg";
		new HCDownloadThread(uriPath, savePath, new CallBack2() {
 
			@Override
			public void success() {
				System.out.println("我就打印一下我传完了 并没有什么卵用");
 
			}
		}).start();
	}
}