자바 ,네이버 실시간 검색어 html소스 파싱하기

에러 많이 터짐;; 이유를 잘 몰곘음;;

import java.io.BufferedInputStream; 

import java.net.HttpURLConnection; 

import java.net.URL; 

public class GetTitle { 

   public static final int buffer_size = 18*1024; 

   public static void main(String[] args) { 

      try{ 

         URL url = new URL("http://naver.com"); 

         HttpURLConnection comm = (HttpURLConnection) url.openConnection(); 

         comm.connect(); 

         byte[] user_buffer = new byte[buffer_size]; 

         BufferedInputStream bis = new BufferedInputStream(comm.getInputStream(), 1024); 

         String s; 

         while(true) { 

            if(bis.read(user_buffer, 0, user_buffer.length) == -1) { 

               s = new String(user_buffer,"UTF8"); 

               break; 

            } 

            else 

            s = new String(user_buffer,"UTF8"); 

            

               if(s.indexOf("<dt id=\"rankTitle\">")!=-1){

               System.out.println(s.indexOf("<dt id=\"rankTitle\">")); 

               System.out.println(s.substring(s.indexOf("<dt id=\"rankTitle\">"),s.indexOf("<form action=\"http://search.naver.com/search.naver\">")));

               }

            

            user_buffer = new byte[buffer_size]; 

         } 

         bis.close(); 

         comm.disconnect(); 

      } catch(Exception e) 

      {