1 基本使用

package com.lzs.net;import java.net.MalformedURLException;import java.net.URL;/** * Created by zaish on 2016-3-20. */public class URLDemo1 {    public static void main(String[] args) throws MalformedURLException {        URL url= new URL("http://www.baidu.com:80/index.html#aa?username=lzs");//绝对路径构建        System.out.println(url.getProtocol());        System.out.println(url.getHost());        System.out.println(url.getPort());        System.out.println(url.getFile());        System.out.println(url.getPath());        System.out.println(url.getRef());//锚点        System.out.println(url.getAuthority());//        System.out.println(url.getQuery());//？参数，如果存在锚点返回null        System.out.println(url.getUserInfo());        URL url1= new URL("http://www.baidu.com:80/a/");//相对路径构建        URL url2=new URL(url1,"b.txt");        System.out.println(url2.toString());    }}

2 获取某网页源码源码

package com.lzs.net;import java.io.*;import java.net.URL;/** * Created by zaish on 2016-3-20. */public class URLDemo2 {    public static void main(String[] args) throws IOException {        URL url= new URL("http://www.baidu.com");        InputStream is=url.openStream();//        int len=0;//        byte[] flust=new byte[1024];//        while (-1!=(len=is.read(flust))){//            System.out.println(new String(flust,0,len));//        }//        is.close();        String msg=null;        BufferedReader br=new BufferedReader(new InputStreamReader(is,"utf-8"));        BufferedWriter bw=new BufferedWriter(new FileWriter("baidu.html"));        while (null!=(msg=br.readLine())){            bw.append(msg);            bw.newLine();        }        bw.flush();        bw.close();        br.close();     }}