jsp 与servlet 的连接

package com.Long.blog;import java.io.IOException;
import java.io.PrintWriter;
import java.sql.Connection;
import java.sql.PreparedStatement;
import java.sql.SQLException;
import java.sql.Statement;
import javax.activation.DataSource;
import javax.sql.*;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
public class BlogServlet extends HttpServlet { private static final long serialVersionUID = 1L;
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
doGet(request,response);
} public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {

request.setCharacterEncoding("UTF-8");


        String title=request.getParameter("title");
        String content=request.getParameter("content");
        String categoryId=request.getParameter("category");
     
        DataSource ds=null;
        
        try{
         Context context =new InitialContext();
          ds=(DataSource) context.lookup("java:/comp/env/jdbc/mysql");
        }catch(Exception e){
        System.out.println("--获取数据源时出错");
        
        }        try{
          Connection conn= ds.getConnection();
        String sql="insert into blog(title,content,category_id,creted_time) value (?,?,?,now())";
        PreparedStatement pstmt=conn.prepareStatement(sql);
        pstmt.setString(1,title );
        pstmt.setString(2,content);
        pstmt.setInt(3,Integer.parseInt(categoryId));
        int result=pstmt.executeUpdate();
        System.out.println(result);
        
        }catch(SQLException e){
         e.printStackTrace();
        }
        
        
}}