java 从网络Url中下载文件

import java.io.File;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.HttpURLConnection;
import java.net.URL;

/**
* Created by liwj on 2017/4/14.
*/
public class Download {

public static void downloadFileFromUrl(String fileUrl,String fileName,String savePath) throws Exception {
//获取连接
URL url=new URL(fileUrl);
HttpURLConnection connection=(HttpURLConnection)url.openConnection();
connection.setConnectTimeout(3*1000);
//设置请求头
connection.setRequestProperty("User-Agent","Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.110 Safari/537.36");
//获取输入流
InputStream in=connection.getInputStream();

File saveDir=new File(savePath);
if(!saveDir.exists()){
saveDir.mkdirs();
}
File file=new File(savePath+fileName);

OutputStream out=new FileOutputStream(file);

byte[] bytes=new byte[1024];
int len=0;
while((len=in.read(bytes))!=-1){
out.write(bytes,0,len);
}
out.close();
in.close();
}

public static void main(String[] args){
try {
downloadFileFromUrl("https://ss0.bdstatic.com/5aV1bjqh_Q23odCf/static/superman/img/logo/bd_logo1_31bdc765.png","baidu.png","E:\\");
}catch (Exception e){

}
}
}