JAVA获取网络图片并保存到本地（随机图片接口）

import java.io.ByteArrayOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import javax.net.ssl.HttpsURLConnection;
 
public class FirstTest {
 
    public static void main(String[] args) throws Exception {
        // TODO 自动生成的方法存根
        
        long start=System.currentTimeMillis();
        System.out.println("开始");
        
        for(int i=1;i<=100;i++) {
//            double r=(0+Math.random()*10000);
//            System.out.println(r);
            String url="https://source.unsplash.com/random";//一个随机图片接口
//            +(0+Math.random()*10000);可以在random后面加入一个随机数避免图片重复
            getImg(url,i);
            System.out.println("完成"+i);
        }
        long end=System.currentTimeMillis();
        System.out.println("运行时间:"+(end-start)/1000+"秒");
    
    
    }
    private static void getImg(String u,int i){
        URL url;
        try {
            url = new URL(u);
            HttpsURLConnection conn = (HttpsURLConnection) url.openConnection();
            conn.setRequestMethod("GET");
            conn.setConnectTimeout(5*1000);
            InputStream in = conn.getInputStream();
            byte[] data = readInputStream(in);
            File f = new File("C:\\Users\\Administrator\\Desktop\\img\\"+i+".jpg");
            FileOutputStream out = new FileOutputStream(f);
            out.write(data);
            out.close();
        } catch (IOException e) {
            // TODO 自动生成的 catch 块
            e.printStackTrace();
        }
    
    }
 
    private static byte[] readInputStream(InputStream ins) throws IOException {
        // TODO 自动生成的方法存根
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        byte[] buffer = new byte[1024];
        int len = 0;
        while ((len = ins.read(buffer)) != -1) {
            out.write(buffer, 0, len);
 
        }
        ins.close();
 
        return out.toByteArray();
    }
 
}