ProdListServlet.java

package com.tedu.jt.web.backend;

import java.io.IOException;

import java.sql.Connection;

import java.sql.PreparedStatement;

import java.sql.ResultSet;

import java.util.ArrayList;

import java.util.List;

import javax.servlet.ServletException;

import javax.servlet.http.HttpServlet;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletResponse;

import com.tedu.jt.utils.JDBCUtils;

/**

 * 查询所有商品信息带到jsp页面进行展示

 */

public class ProdListServlet

extends HttpServlet {

private static final long serialVersionUID = 1L;

protected void doGet(

HttpServletRequest request,

HttpServletResponse response)

throws ServletException,

IOException {

// 1.查询所有商品信息

List<Product> list = findProdList();

System.out.println("list: "+list);

// 2.将List集合存入request域中

request.setAttribute("list", list);

/*

* 3.通过转发将List集合带到商品列表 (prod_list.jsp)页面进行展示

*/

request.getRequestDispatcher(

"/backend/prod_list.jsp")

.forward(request, response);

}

/**

* 用于查询所有的商品信息

* 

* @return List<Product>集合

*/

private List<Product> findProdList() {

Connection conn = null;

PreparedStatement ps = null;

ResultSet rs = null;

try {

// 1.获取连接(从连接池中获取一个连接对象)

conn = JDBCUtils.getConn();

// 2.声明sql语句

String sql = "select * from product";

// 3.获取传输器

ps = conn.prepareStatement(sql);

// 4.执行sql

rs = ps.executeQuery();

// 5.声明List集合用于存储所有的商品信息

List<Product> list = new ArrayList<Product>();

// 6.遍历结果集, 将结果存入List集合中

while(rs.next()){

//7.声明Product对象用于封装商品信息

Product prod = new Product();

prod.setId(rs.getInt("id"));

prod.setName(rs.getString("name"));

prod.setCategory(

rs.getString("category"));

prod.setPrice(rs.getDouble("price"));

prod.setPnum(rs.getInt("pnum"));

prod.setDescription(

rs.getString("description"));

//8.将Product对象存入List集合

list.add(prod);

}

return list;

} catch (Exception e) {

System.out.println(

"商品信息查询失败!!");

e.printStackTrace();

throw new RuntimeException(

"商品信息查询失败!");

} finally {

JDBCUtils.close(conn, ps, rs);

}

}

protected void doPost(

HttpServletRequest request,

HttpServletResponse response)

throws ServletException,

IOException {

doGet(request, response);

}

}