import java.net.*;import java.io.*;public class ParseURL {    public static void main(String[] args)    throws Exception {        URL aURL = new URL("http://java.sun.com:80/docs/books/tutorial" + "/index.html?name=networking#DOWNLOADING");        System.out.println("protocol = " + aURL.getProtocol());        System.out.println("authority = " + aURL.getAuthority());        System.out.println("host = " + aURL.getHost());        System.out.println("port = " + aURL.getPort());        System.out.println("path = " + aURL.getPath());        System.out.println("query = " + aURL.getQuery());        System.out.println("filename = " + aURL.getFile());        System.out.println("ref = " + aURL.getRef());    }}

输出

ut:ut:protocol = http

ut:ut:authority = localhost:8080

ut:ut:host = localhost

ut:ut:port = 8080

ut:ut:path = /UT2.0/login.action

ut:ut:query = null

ut:ut:filename = /UT2.0/login.action

ut:ut:ref = null

 

判断URL是否合法

文件：Test.java

import java.net.HttpURLConnection;import java.net.URL;public class Test {    public static void main(String[] args) {       System.out.println(exists("http://www.baidu.com"));       System.out.println(exists("http://www.baidu.com/XXXXX.html"));    }    static boolean exists(String URLName) {       try {           //设置此类是否应该自动执行 HTTP 重定向（响应代码为 3xx 的请求）。           HttpURLConnection.setFollowRedirects(false);           //到 URL 所引用的远程对象的连接           HttpURLConnection con = (HttpURLConnection) new URL(URLName).openConnection();           /* 设置 URL 请求的方法， GET POST HEAD OPTIONS PUT DELETE TRACE 以上方法之一是合法的，具体取决于协议的限制。*/           con.setRequestMethod("HEAD");           //从 HTTP 响应消息获取状态码           return (con.getResponseCode() == HttpURLConnection.HTTP_OK);       } catch (Exception e) {           e.printStackTrace();           return false;        }    }}