java中URLConnection的简单使用

package com.company;

import java.io.*;
import java.net.*;
import java.util.*;

public class Main {

    public static void main(String[] args) {

        try {
            //URL url = new URL("http://www.baidu.com:80/en/index.html?name=john#first");
            URL url = new URL("http://www.java.com");
            URLConnection urlConnection = url.openConnection();
            InputStream inputStream = urlConnection.getInputStream();
            /*
            * InputStream inputStream = url.openStream(); 除了读取之外功能不如上面的功能多
            * */

            System.out.println( urlConnection.getContentLength());
            System.out.println(urlConnection.getContentEncoding());
            System.out.println(urlConnection.getContentType());
            System.out.println(urlConnection.getDate());
            System.out.println(urlConnection.getExpiration());

            Map<String,List<String>> headers = urlConnection.getHeaderFields(); //返回头部信息
            //以下输出头部信息
            Set<Map.Entry<String,List<String>>> set = headers.entrySet();
            for(Map.Entry<String,List<String>> m : set){
                String key = m.getKey();
                System.out.println("Header Name : "+key);
                List<String> value = m.getValue();
                System.out.println("Header Value : ");
                for(String str : value){
                    System.out.println("        " + value);
                }
            }

         }catch (Exception e){

        }

    }
}