图片下载是一件很简单的事，那么用java如何实现网络图片下载到本地呢（例如我们从网络上爬取图片）

package org.nutz.common.util;

import java.io.*;
import java.net.URL;
import java.net.URLConnection;

/**
 * @author: Haiming Yu
 * @createDate:2022/8/16
 * @description:
 */
public class ImageDownload {

    /**
     * 文件下载到指定路径
     *
     * @param urlString 链接
     * @param savePath  保存路径
     * @param filename  文件名
     * @throws Exception
     */
    public static void download(String urlString, String savePath, String filename) throws IOException {
        // 构造URL
        URL url = new URL(urlString);
        // 打开连接
        URLConnection con = url.openConnection();
        //设置请求超时为20s
        con.setConnectTimeout(20 * 1000);
        //文件路径不存在 则创建
        File sf = new File(savePath);
        if (!sf.exists()) {
            sf.mkdirs();
        }
        //jdk 1.7 新特性自动关闭
        try (InputStream in = con.getInputStream();
             OutputStream out = new FileOutputStream(sf.getPath() + "\\" + filename)) {
            //创建缓冲区
            byte[] buff = new byte[1024];
            int n;
            // 开始读取
            while ((n = in.read(buff)) >= 0) {
                out.write(buff, 0, n);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }


    }

    public static void main(String[] args) throws Exception {
        download("https://via.placeholder.com/300.png", "d:\\mnt\\", "sample.png");
    }
}