【网络编程】-- 06 URL

网络编程

7 URL

统一资源定位符

一般组成：

协议://IP地址:端口/项目名/资源

练习：

package com.duo.lesson04;

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

public class URLDemo1 {

    public static void main(String[] args) throws MalformedURLException {
        URL url = new URL("http://localhost:8080/helloworld/index.jsp?username=duo&password=123");  //这是伪造的
        System.out.println(url.getProtocol());  //协议
        System.out.println(url.getHost());  //主机IP
        System.out.println(url.getPort());  //端口
        System.out.println(url.getPath());  //文件地址
        System.out.println(url.getFile());  //文件全路径
        System.out.println(url.getQuery());  //参数
    }
}

运行结果：

从网络已知地址下载文件：

package com.duo.lesson04;

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

//URLDownLoad
public class URLDemo2 {

    public static void main(String[] args) throws Exception {
        //1.下载地址
        URL url = new URL("https://m801.music.126.net/20231211151812/66fdd3300209141a7bb0dfcc25b0fa15/jdyyaac/obj/w5rDlsOJwrLDjj7CmsOj/28481826595/0184/e2b0/9241/c646ae0beafd28c4b35720984816a7f4.m4a");

        //2.创建连接以及IO流
        URLConnection urlConnection = url.openConnection();  //URL连接
        InputStream inputStream = urlConnection.getInputStream();
        FileOutputStream fOS = new FileOutputStream("f4.m4a");  //读出文件

        //3.写文件至读出文件中
        byte[] buffer = new byte[1024];
        int len;
        while ((len = inputStream.read(buffer)) != -1) {
            fOS.write(buffer, 0, len);
        }

        //4.关闭资源
        fOS.close();
        inputStream.close();
    }
}

运行结果：

打开.m4a文件可正常播放！