java 网络API访问 web 站点

package cn.magicdu.think.socket;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.List;
import java.util.Map;

/**
 * Java 访问web 站点
 *
 * @author xiaoduc
 *
 */
public class HttpConnTest {
    public static void main(String[] args)  throws Exception{
        //创建URL对象
        URL url=new URL("http://www.baidu.com");
        //用URL创建 HTTPConnection 对象
        HttpURLConnection conn= (HttpURLConnection) url.openConnection();
        //打开连接
        conn.connect();
        //打印请求响应的头部信息
        Map<String,List<String>> header=conn.getHeaderFields();
        for(String key:header.keySet()){
            System.out.println(key+":"+header.get(key));
        }
        //打印响应内容
        BufferedReader br=new BufferedReader(new InputStreamReader(conn.getInputStream(), "UTF-8"));
        String str=null;
        while((str=br.readLine())!=null){
            System.out.println(str);
        }
        conn.disconnect();
    }
}

运行结果：