URL使用

• 统一资源定位符 : 定位资源，定位互联网上的某一个具体资源
• DNS域名解析 : 将域名解析成为对应的ip地址
• URL的组成

协议://ip地址:端口/项目名/资源

• 使用URL下载网络资源

package com.socket.url;

import com.sun.jndi.toolkit.url.Uri;

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

public class URLDownload {
    public static void main(String[] args) throws Exception {
        URL url = new URL("https://m801.music.126.net/20210206231639/4f53ae118824d1098d8fda224f215089/jdyyaac/5209/5158/010e/ec2ebb10a1f27cc0d06a6d31dcb60096.m4a");
        HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
        System.out.println(url.getProtocol());//获取协议
        System.out.println(url.getHost());//获取主机ip
        System.out.println(url.getPort());//获取端口
        System.out.println(url.getPath());//获取资源路径
        System.out.println(url.getDefaultPort());//获取默认端口
        System.out.println(url.getFile());//获取文件
        System.out.println(url.getQuery());//获取参数

        InputStream inputStream = urlConnection.getInputStream();
        FileOutputStream fos = new FileOutputStream("f.m4a");

        byte[] bytes = new byte[1024];
        int len;

        while ((len = inputStream.read(bytes)) != -1){
            fos.write(bytes,0,len);
        }

        fos.close();
        inputStream.close();
        urlConnection.disconnect();
    }
}