URL的使用下载资源

##URL的使用

package UdpCommuncation;

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/helloworld/index.jsp?useername=yan=123");

        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());//路径
        System.out.println(url.getFile());//文件
        System.out.println(url.getQuery());//参数


    }
}

使用URL下载资源

需要打开Tomcat

package UdpCommuncation;

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

public class Down {
    
    public static void main(String[] args) throws IOException {
    
        //1,下载地址
        URL url=new URL("https://m704.music.126.net/20220725150910/04899645bb2ebc8ef5dbf6bcb1e07814/jdyyaac/obj/w5rDlsOJwrLDjj7CmsOj/15384022047/73a2/a864/8dbb/1bdbc100f5143a96c0c34c5698e61732.m4a?authSecret=00000182341951661b4b0aaba0c8b0c8");

        //2,连接到这个资源 HTTP
        HttpURLConnection urlConnection=(HttpURLConnection) url.openConnection();
        InputStream inputStream=urlConnection.getInputStream();

        FileOutputStream fos = new FileOutputStream("mi.m4a");
        byte[] buffer = new byte[1024];
        int len;
        while((len=inputStream.read(buffer))!=-1){
    
            fos.write(buffer,0,len);
        }
        fos.close();
        inputStream.close();
        urlConnection.disconnect();//断开连接

    }
}