(jsp 和 servlet功能篇) jsp+servlet+javaBean 实现分页代码（mysql 数据库）

实例代码：

JavaBean

package Bean;
//物品类
public class Goods
{
 private int goodsid;  // 物品编号
 public String goodsname;   // 物品名称
 private float price;        // 物品单件

 public void setGoodsid(int goodsid)
 {
  this.goodsid = goodsid;
 }
 public int getGoodsid()
 {
  return goodsid;
 }
 // 物品名称
 public void setGoodsname(String goodsname)
 {
  this.goodsname = goodsname;
 }
 public String getGoodsname()
 {
  return goodsname;
 }
 // 物品价格
 public void setPrice(float price)
 {
  this.price = price;
 }
 public float getPrice()
 {
  return price;
 }
}

数据库（单列模式）

单例类

package util;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.SQLException;

public class DbConnection {
 private static Connection conn=null;
 private String driver="com.mysql.jdbc.Driver";
 private String url="jdbc:mysql://localhost:3306/mydata";
 private String user="root";
 private String password="1234567";
 
 private DbConnection(){
  try {
   Class.forName(driver);
   conn=DriverManager.getConnection(url, user, password);
  } catch (ClassNotFoundException e) {
   e.printStackTrace();
  } catch (SQLException e) {
   e.printStackTrace();
  }
 }
 
 public static Connection getConnection() {
  if(conn==null){
   new DbConnection();
  }
  return conn;
 }
}

数据库操作逻辑代码：

数据库访问实现

package DAO;

import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.ArrayList;

import Bean.Goods;

import util.DbConnection;

public class Dao {
 private static Connection conn;
 private static ResultSet rs;
 private static Statement stmt;
 private static int pagesize=5;
 static{
  conn=DbConnection.getConnection();
 }
 
 //通用的查询方法
 public static ResultSet ExecuteQuery(String sql) {
  try {
   stmt=conn.createStatement();
   rs=stmt.executeQuery(sql);
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return rs;
 }
 
 //分页逻辑
 public static ArrayList getGoodsList(int currentpageno){
  ArrayList GoodsList=new ArrayList();
  int BeginRecord=(currentpageno-1)*pagesize;
  int EndRecord=currentpageno*pagesize;
  rs=ExecuteQuery("select * from goods limit "+BeginRecord+","+EndRecord);
  try {
   while(rs.next()){
    Goods goods=new Goods();
    goods.setGoodsid(rs.getInt(1));
    goods.setGoodsname(rs.getString(2));
    goods.setPrice(rs.getFloat(3));
    GoodsList.add(goods);
   }
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return GoodsList;
 }
 
 //统计记录数
 public static int getPageCount(){
  int total=0;
  int PageCount=0;
  rs=ExecuteQuery("select count(*) from goods");
  try {
   if(rs.next()){
    total=rs.getInt(1);
    PageCount=(total-1)/pagesize+1;
   }
  } catch (SQLException e) {
   e.printStackTrace();
  }
  return PageCount;
 }
}

servlet控制器

servlet控制器

package servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.ArrayList;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import Bean.Goods;
import DAO.Dao;

public class GetLimiteGoods extends HttpServlet {
 private static final long serialVersionUID = 1L;
 public void doGet(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
  response.setContentType("text/html");
  String pageno= request.getParameter("currentpageno");
  int currentpageno=1;
  if(pageno!=null){
   currentpageno=Integer.parseInt(pageno);
  }
  ArrayList GoodsList=Dao.getGoodsList(currentpageno);
  request.setAttribute("GoodsList", GoodsList);
  request.setAttribute("currentpageno", currentpageno);
  request.setAttribute("PageCount", Dao.getPageCount());
  request.getRequestDispatcher("/LimiteGoods.jsp").forward(request, response);
 }

 public void doPost(HttpServletRequest request, HttpServletResponse response)
   throws ServletException, IOException {
           doGet(request,rsponse);
 }
}

配置文件

xml配置：



  
    This is the description of my J2EE component
    This is the display name of my J2EE component
    GetLimiteGoods
    servlet.GetLimiteGoods
  

  
    GetLimiteGoods
    /servlet/GetLimiteGoods
  

jsp代码：

表现层jsp

<%@ page language="java" contentType="text/html; charset=UTF-8"
 pageEncoding="UTF-8"%>
 <%@ taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>


 
  
  
 
 
 
 
   首页
   上一页
  
  
   下一页
   尾页
  
  
    

   

    

     商品编号
    
    

     商品名称
    
    

     商品价格
    
   
   

     

      ${goods.goodsid}
     
     

      ${goods.goodsname}
     
     

      ${goods.price}