java下载图片

import java.io.BufferedReader; 
import java.io.ByteArrayOutputStream; 
import java.io.File; 
import java.io.FileOutputStream; 
import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.HttpURLConnection; 
import java.net.URL; 
 
public class UrlResource { 
 
    public static void main(String[] args){ 
        try { 
            System.out.println(UrlResource.getUrlDetail("http://www.baidu.com",true)); 
            saveUrlFile("http://www.baidu.com/img/baidu_jgylogo3.gif", "D:\\1.gif"); 
        } catch (Exception e) { 
            e.printStackTrace(); 
        } 
    } 
     
    //获取网络文件，转存到fileDes中，fileDes需要带文件后缀名 
    public static void saveUrlFile(String fileUrl,String fileDes) throws Exception 
    { 
        File toFile = new File(fileDes); 
        if (toFile.exists()) 
        { 
//          throw new Exception("file exist"); 
            return; 
        } 
        toFile.createNewFile(); 
        FileOutputStream outImgStream = new FileOutputStream(toFile); 
        outImgStream.write(getUrlFileData(fileUrl)); 
        outImgStream.close(); 
    } 
     
    //获取链接地址文件的byte数据 
    public static byte[] getUrlFileData(String fileUrl) throws Exception 
    { 
        URL url = new URL(fileUrl); 
        HttpURLConnection httpConn = (HttpURLConnection) url.openConnection(); 
        httpConn.connect(); 
        InputStream cin = httpConn.getInputStream(); 
        ByteArrayOutputStream outStream = new ByteArrayOutputStream(); 
        byte[] buffer = new byte[1024]; 
        int len = 0; 
        while ((len = cin.read(buffer)) != -1) { 
            outStream.write(buffer, 0, len); 
        } 
        cin.close(); 
        byte[] fileData = outStream.toByteArray(); 
        outStream.close(); 
        return fileData; 
    } 
     
    //获取链接地址的字符数据，wichSep是否换行标记 
    public static String getUrlDetail(String urlStr,boolean withSep) throws Exception 
    { 
        URL url = new URL(urlStr); 
        HttpURLConnection httpConn = (HttpURLConnection)url.openConnection(); 
        httpConn.connect(); 
        InputStream cin = httpConn.getInputStream(); 
        BufferedReader reader = new BufferedReader(new InputStreamReader(cin,"UTF-8")); 
        StringBuffer sb = new StringBuffer(); 
        String rl = null; 
        while((rl = reader.readLine()) != null) 
        { 
            if (withSep) 
            { 
                sb.append(rl).append(System.getProperty("line.separator")); 
            } 
            else 
            { 
                sb.append(rl); 
            } 
        } 
        return sb.toString(); 
    } 
     
}