根据 url 下载图片到本地

package com.newlixon.util;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FileOutputStream;
import java.net.HttpURLConnection;
import java.net.URL;
/**
*
* @author ZJ
* 根据图片url,下载图片
*/

public class PicExport {

public static void download(String _url) throws Exception{
//获取文件名，文件名实际上在URL中可以找到
String fileName = _url.substring(_url.lastIndexOf("/")+1).toString();
//这里服务器上要将此图保存的路径
//String savePath = getRequest().getRealPath(UPLOAD_PATH);
//下载图片存放的路径
String savePath = "C:\\barcode\\";
try {
URL url = new URL(_url);/*将网络资源地址传给,即赋值给url*/
/*此为联系获得网络资源的固定格式用法，以便后面的in变量获得url截取网络资源的输入流*/
HttpURLConnection connection = (HttpURLConnection)url.openConnection();
DataInputStream in = new DataInputStream(connection.getInputStream());
/*此处也可用BufferedInputStream与BufferedOutputStream*/
DataOutputStream out = new DataOutputStream(new FileOutputStream(savePath+fileName));
/*将参数savePath，即将截取的图片的存储在本地地址赋值给out输出流所指定的地址*/
byte[] buffer = new byte[4096];
int count = 0;
/*将输入流以字节的形式读取并写入buffer中*/
while ((count = in.read(buffer)) > 0) {
out.write(buffer, 0, count);
}
out.close();/*后面三行为关闭输入输出流以及网络资源的固定格式*/
in.close();
connection.disconnect();
//返回内容是保存后的完整的URL

} catch (Exception e) {
}

}
}