URL
URL:统一资源定位符
DNS:域名解析 https://www.baidu.com/ 解析成一个ip
1.协议://ip地址:端口/项目名/资源
package com.zr.lesson04;
import java.net.MalformedURLException;
import java.net.URL;
public class URLDemo01 {
public static void main(String[] args) throws MalformedURLException {
URL url = new URL("http://localhost:8080/hello/index.jsp?username=zr&password=88");
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
System.out.println(url.getFile());//全路径
System.out.println(url.getQuery());//参数
}
}
下载歌曲
package com.zr.lesson04;
import java.io.FileOutputStream;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
public class URLDown {
public static void main(String[] args) throws Exception {
//下载地址
URL url = new URL("https://m10.music.126.net/20200825221815/b99fa2c540477bc1e8ffefd88ef6bd04/yyaac/
obj/wonDkMOGw6XDiTHCmMOi/3530218359/48c9/4784/5a64/948f94563dbf15284e934c955945ed03.m4a");
//连接到这个资源
HttpURLConnection urlConnection = (HttpURLConnection) url.openConnection();
InputStream is = urlConnection.getInputStream();
FileOutputStream fos = new FileOutputStream("m.m4a");
byte[] buffer = new byte[1024];
int len;
while ((len=is.read(buffer))!=-1){
fos.write(buffer,0, len);//写出数据
}
fos.close();
is.close();
urlConnection.disconnect();
}
}