package com.dragon.java.downloadpic;

import java.io.BufferedInputStream;

import java.io.BufferedOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

import java.io.InputStream;

import java.net.HttpURLConnection;

import java.net.URL;

public class HttpURLConnectionUtil {

        // 通过get请求得到读取器响应数据的数据流

    public static InputStream getInputStreamByGet(String url) {

        try {

            HttpURLConnection conn = (HttpURLConnection) new URL(url)

                    .openConnection();

            conn.setReadTimeout(5000);

            conn.setConnectTimeout(5000);

            conn.setRequestMethod("GET");

            if (conn.getResponseCode() == HttpURLConnection.HTTP_OK) {

                InputStream inputStream = conn.getInputStream();

                return inputStream;

            }

        } catch (IOException e) {

            e.printStackTrace();

        }

        return null;

    }

        // 将服务器响应的数据流存到本地文件

    public static void saveData(InputStream is, File file) {

        try (BufferedInputStream bis = new BufferedInputStream(is);

                BufferedOutputStream bos = new BufferedOutputStream(

                        new FileOutputStream(file));) {

            byte[] buffer = new byte[1024];

            int len = -1;

            while ((len = bis.read(buffer)) != -1) {

                bos.write(buffer, 0, len);

                bos.flush();

            }

        } catch (IOException e) {

            e.printStackTrace();

        }

    }

}

package com.dragon.java.downloadpic;

import java.io.File;

import java.io.InputStream;

/*

 * 1. 从下面的地址下载图片，并保存在文件中。

 http://img.coocaa.com/www/attachment/forum/201602/16/085938u86ewu4l8z6flr6w.jpg

 *要求：封装相应的工具类*

 */

public class Test {

    public static void main(String[] args) {

        String url = "http://img.coocaa.com/www/attachment/forum/201602/16/085938u86ewu4l8z6flr6w.jpg";

　　　　　　String[] split = url.split("\\/");
　　　　　　String fileName = split[split.length - 1];
　　　　　　File file = new File("f:/", fileName);

        InputStream inputStream = HttpURLConnectionUtil

                .getInputStreamByGet(url);

        HttpURLConnectionUtil.saveData(inputStream, file);

    }

}