本文转自:http://blog.youkuaiyun.com/xb12369/article/details/40543649/
package com.xy6;
import java.io.ByteArrayOutputStream;
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 Demo3 {
/**
* 从网络Url中下载文件
*
* @param urlStr
* @param fileName
* @param savePath
* @throws IOException
*/
public static void downLoadFromUrl(String urlStr, String fileName, String savePath) throws IOException {
URL url = new URL(urlStr);
HttpURLConnection conn = (HttpURLConnection) url.openConnection();
//设置超时间为3秒
conn.setConnectTimeout(3 * 1000);
//防止屏蔽程序抓取而返回403错误
conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");
//得到输入流
InputStream inputStream = conn.getInputStream();
//获取自己数组
byte[] getData = readInputStream(inputStream);
//文件保存位置
File saveDir = new File(savePath);
if (!saveDir.exists()) {
saveDir.mkdir();
}
File file = new File(saveDir + File.separator + fileName);
FileOutputStream fos = new FileOutputStream(file);
fos.write(getData);
if (fos != null) {
fos.close();
}
if (inputStream != null) {
inputStream.close();
}
System.out.println("info:" + url + " download success");
}
/**
* 从输入流中获取字节数组
*
* @param inputStream
* @return
* @throws IOException
*/
public static byte[] readInputStream(InputStream inputStream) throws IOException {
byte[] buffer = new byte[1024];
int len = 0;
ByteArrayOutputStream bos = new ByteArrayOutputStream();
while ((len = inputStream.read(buffer)) != -1) {
bos.write(buffer, 0, len);
}
bos.close();
return bos.toByteArray();
}
public static void main(String[] args) {
try {
downLoadFromUrl(
"http://avatar.youkuaiyun.com/C/1/C/1_daxiang12092205.jpg",
"logo.jpg", "d:/");
} catch (Exception e) {
// TODO: handle exception
e.printStackTrace();
}
}
}