Java使用Http实现网络图片的下载

package com.io.image.demo;

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

/**
 * 通过URL下载网络图片到本地
 */
public class DownLoadImageByHttp 
{

/**
* 把图片资源保存到本地
* 
* @param urlPath 网络图片的地址
* @param localPath 保存到本地的图片路径
* @param fileName 图片的名称
*/

public void downLoadImageToDisk(String urlPath,String localPath, String fileName)
{

FileOutputStream fos = null;

byte[] bytes = null;

File file = null;

try 

{

file = new File(localPath + File.separator + fileName);

bytes = getImageFromNetByUrl(urlPath);

fos = new FileOutputStream(file);

fos.write(bytes);

fos.flush();

fos.close();

}

catch (FileNotFoundException e) 

{

e.printStackTrace();

} 

catch (IOException e) 

{

e.printStackTrace();

}

}

/**
* 通过URL获取网络图片
* 
* @param urlPath 网络图片的地址
* @return
*/
private byte[] getImageFromNetByUrl(String urlPath)

{

HttpURLConnection httpConn = null;

InputStream inStream = null;

byte[] bytes = null;

try 

{

URL url = new URL(urlPath);

httpConn = (HttpURLConnection) url.openConnection();

httpConn.setRequestMethod("GET");

httpConn.setConnectTimeout(5*1000);

httpConn.setDoInput(true);

httpConn.connect();

if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) 

{

inStream = httpConn.getInputStream();

bytes = readInputStream(inStream);

}

return bytes;

} 

catch (MalformedURLException e) 

{

e.printStackTrace();

} 

catch (IOException e) 

{

e.printStackTrace();

}

return null;

}

/**

* 从输入流读取数据，写到输出流中
* 
* @param inStream 图片的输入流数据
* @return
*/
private byte[] readInputStream(InputStream inStream) 
{

ByteArrayOutputStream outStream = new ByteArrayOutputStream();

byte[] bytes = new byte[1024];  

          int len = 0;  

          try 
        {

while((len=inStream.read(bytes)) != -1 )

{  

   outStream.write(bytes, 0, len);  

}

inStream.close();

} 

          catch (IOException e) 

{

e.printStackTrace();

}  

return outStream.toByteArray();

}

}