URL下载

URL下载

java里面什么东西都是流，文件流、输入流、输出流

URL (Uniform Resource Locator) 统一资源定位符 定位网络资源

DNS 域名解析：将域名解析为ip

格式

协议://ip地址:port/项目名/文件

URL类

package com.example.network;

import java.net.MalformedURLException;
import java.net.URL;

public class TestUrl {
    public static void main(String[] args) throws MalformedURLException {
//        URL url = new URL("http://localhost:8080/test/test.txt?user=ohmydream&&password=123");
        URL url = new URL("https://www.baidu.com");
        System.out.println(url.getAuthority());// ip+端口
        System.out.println(url.getProtocol()); // 协议：http
        System.out.println(url.getHost()); // ip
        System.out.println(url.getPort()); // 端口
        System.out.println(url.getFile()); // 文件
        System.out.println(url.getPath()); // 路径
        System.out.println(url.getQuery()); // 参数
    }
}

网络资源下载

package com.example.network;

import javax.net.ssl.HttpsURLConnection;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;

public class TestUrlDownload {
    public static void main(String[] args) throws IOException {
        URL url = new URL("https://gimg2.baidu.com/image_search/src=http%3A%2F%2Fpic167.nipic.com%2Ffile%2F20180604%2F25840778_184754781087_2.jpg&refer=http%3A%2F%2Fpic167.nipic.com&app=2002&size=f9999,10000&q=a80&n=0&g=0n&fmt=jpeg?sec=1639969528&t=6e8d3b72a717c5d2b36645904a612bf7");
        HttpsURLConnection connection = (HttpsURLConnection) url.openConnection();
        InputStream ios = connection.getInputStream();
        FileOutputStream fos = new FileOutputStream("baby.jpg");
        byte[] buffer = new byte[1024];
        int len;
        while ((len = ios.read(buffer)) != -1) {
            fos.write(buffer, 0, len);
        }

        fos.close();
        ios.close();
        connection.disconnect();

    }
}