java使用url读取网页资源

package com.susu;

import java.io.BufferedInputStream;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.MalformedURLException;
import java.net.URL;

public class URLDemo2 {
  public static void main(String[] args) {
    try {
      //创建一个url实例
      URL url=new URL("http://www.baidu.com");
      //通过url的openStream获取url对象所表示资源的字节输入流
      InputStream is=url.openStream();
      //将字节输入流转换为字符输入流
      InputStreamReader isr=new InputStreamReader(is,"utf-8");
      //为字符输入流添加缓冲
      BufferedReader br=new BufferedReader(isr);
      String res=null;
      String line=null;
      //读取数据
      while((line=br.readLine())!=null){
        res+=line;
      }
      br.close();
      isr.close();
      is.close();
      System.out.println(res);
    } catch (MalformedURLException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    } catch (IOException e) {
      // TODO Auto-generated catch block
      e.printStackTrace();
    }
    
  }
}