直接上代码：

package com.lemon.photo;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.net.MalformedURLException;
import java.net.URL;
public class ReadPhotoUrl {
    public static void main(String[] args) {
        String url =
                "https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1569407230663&di=51db9c03ac5432c1cdf94cd4fdabb5a4&imgtype=0&src=http%3A%2F%2Fb-ssl.duitang.com%2Fuploads%2Fblog%2F201310%2F18%2F20131018213535_2yTwn.jpeg";
                String path="d:/pic.png";
        downloadPicture(url,path);
    }
    //链接url下载图片
    /**
     * 功能描述: 
     * @param:  urlList  图片url地址
     * @param:  path     下载到本地的路径
     * @return: void
     * @author: lemon
     * @since: 2019/9/27 0027
     */
    private static void downloadPicture(String urlList,String path) {
        try {
            URL url = new URL(urlList);
            DataInputStream dataInputStream = new DataInputStream(url.openStream());
            FileOutputStream fileOutputStream = new FileOutputStream(new File(path));
            ByteArrayOutputStream output = new ByteArrayOutputStream();
            byte[] buffer = new byte[1024];
            int length;
            while ((length = dataInputStream.read(buffer)) > 0) {
                output.write(buffer, 0, length);
            }
            fileOutputStream.write(output.toByteArray());
            dataInputStream.close();
            fileOutputStream.close();
        } catch (MalformedURLException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}