利用MVC模式简单设计jsp分页效果

利用Mysql创建一个表Car

用Eclipse创建一个Dynamic Web Project

在lib目录下导入Mysql的jar包

创建如下文件

package com.bean;

public class Car {
    private String code;
    private String name;
    private String brand;
    private String time;
    private double oil;
    private int powers;
    private int exhaust;
    private double price;
    private String image;
    public String getCode() {
        return code;
    }
    public void setCode(String code) {
        this.code = code;
    }
    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public String getBrand() {
        return brand;
    }
    public void setBrand(String brand) {
        this.brand = brand;
    }
    public String getTime() {
        return time;
    }
    public void setTime(String time) {
        this.time = time;
    }
    public double getOil() {
        return oil;
    }
    public void setOil(double oil) {
        this.oil = oil;
    }
    public int getPowers() {
        return powers;
    }
    public void setPowers(int powers) {
        this.powers = powers;
    }
    public int getExhaust() {
        return exhaust;
    }
    public void setExhaust(int exhaust) {
        this.exhaust = exhaust;
    }
    public double getPrice() {
        return price;
    }
    public void setPrice(double price) {
        this.price = price;
    }
    public String getImage() {
        return image;
    }
    public void setImage(String image) {
        this.image = image;
    }
    
}

package com.dao;

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

import com.bean.Car;

public class CarDao {
    private Connection conn;
    private PreparedStatement stat;
    private ResultSet rs;
    
    //获取总页数
    public int getPageCount(int pageSize) throws Exception{
        conn= DBConnection.getconnection();
        String sql= "select count(*) from car";
        stat=conn.prepareStatement(sql);
        rs= stat.executeQuery();
        rs.next();
        int rowCount = rs.getInt(1);
        int pageCount = (int)Math.ceil((1.0*rowCount/pageSize));
        conn.close();
        return pageCount;
        
    }
    //获取第几页的数据
    public ArrayList<Car> getPageCar(int pageNo,int pageSize){
        ArrayList<Car> list = new ArrayList<Car>();
        try {
            conn=DBConnection.getconnection();
            String sql="select * from car limit ?,?";
            stat=conn.prepareStatement(sql);
            stat.setInt(1, (pageNo-1)*pageSize);
            stat.setInt(2, pageSize);
            rs=stat.executeQuery();
            while(rs.next()){
                Car c = new Car();
                c.setCode(rs.getString(1));
                c.setName(rs.getString(2));
                c.setBrand(rs.getString(3));
                c.setTime(rs.getString(4));
                c.setOil(rs.getDouble(5));
                c.setPowers(rs.getInt(6));
                c.setExhaust(rs.getInt(7));
                c.setPrice(rs.getDouble(8));
                c.setImage(rs.getString(9));
                list.add(c);
            }
        } catch (Exception e) {
            // TODO 自动生成的 catch 块
            e.printStackTrace();
        }
        finally{
            try {
                conn.close();
            } catch (SQLException e) {
                // TODO 自动生成的 catch 块
                e.printStackTrace();
            }
        }
        
        return list;
        
    }
    
    public ArrayList<Car> select(){
        ArrayList<Car> list = new ArrayList<Car>();
        try {
            conn=DBConnection.getconnection();
            String sql= "select * from car";
            stat=conn.prepareStatement(sql);
            rs = stat.executeQuery();
            
            while(rs.next()){
                Car c = new Car();
                c.setCode(rs.getString(1));
                c.setName(rs.getString(2));
                c.setBrand(rs.getString(3));
                c.setTime(rs.getString(4));
                c.setOil(rs.getDouble(5));
                c.setPowers(rs.getInt(6));
                c.setExhaust(rs.getInt(7));
                c.setPrice(rs.getDouble(8));
                c.setImage(rs.getString(9));
                list.add(c);
            }
        } catch (Exception e) {
            // TODO 自动生成的 catch 块
            e.printStackTrace();
        }
        finally{
            try {
                conn.close();
            } catch (SQLException e) {
                // TODO 自动生成的 catch 块
                e.printStackTrace();
            }
        }
        
        return list;
        
    }
    public Car select(String key){
        Car c = null;
        try {
            conn= DBConnection.getconnection();
            String sql = "select * from car where code=?";
            stat= conn.prepareStatement(sql);
            stat.setString(1, key);
            rs= stat.executeQuery();
            while(rs.next()){
                 c = new Car();
                 c.setCode(rs.getString(1));
                 c.setName(rs.getString(2));
                 c.setBrand(rs.getString(3));
                 c.setTime(rs.getString(4));
                 c.setOil(rs.getDouble(5));
                 c.setPowers(rs.getInt(6));
                 c.setExhaust(rs.getInt(7));
                 c.setPrice(rs.getDouble(8));
                 c.setImage(rs.getString(9));
                
            }
        } catch (Exception e) {
            // TODO 自动生成的 catch 块
            e.printStackTrace();
        }
        return c;
        
    }
}

package com.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.util.ResourceBundle;



public class DBConnection {
    public static Connection getconnection() throws Exception{
        String drv = ResourceBundle.getBundle("db").getString("drv");
        String url = ResourceBundle.getBundle("db").getString("url");
        String uid = ResourceBundle.getBundle("db").getString("uid");
        String pwd = ResourceBundle.getBundle("db").getString("pwd");
        
        Class.forName(drv);
        Connection conn = DriverManager.getConnection(url,uid,pwd);
        return conn;
        
    }
}

db.properties文件是保护文件，里面要写用户密码。如下：

drv=com.mysql.jdbc.Driver
url=jdbc:mysql://127.0.0.1:3306/mydb?characterEncoding=GBK
uid=root
pwd=

 com.servlet包下的文件都是servlet类型的

package com.servlet;

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

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

import com.bean.Car;
import com.dao.CarDao;

/**
 * Servlet implementation class Showservlet
 */
@WebServlet("/show")
public class Showservlet extends HttpServlet {
    private static final long serialVersionUID = 1L;
    private final int PAGESIZE =3;
    /**
     * @see HttpServlet#HttpServlet()
     */
    public Showservlet() {
        super();
        // TODO Auto-generated constructor stub
    }

    /**
     * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取数据
        int pageNo = 1;
        String s = request.getParameter("pg");
        if(s !=null){
            pageNo=Integer.parseInt(s);
        }
        //处理数据
        try {
            int pageCount =  new CarDao().getPageCount(PAGESIZE);
            ArrayList<Car> list  = new  CarDao().getPageCar(pageNo, PAGESIZE);
            
            int pagePrev = pageNo>1?pageNo-1:1;
            int pageNext = pageNo<pageCount?pageNo+1:pageCount;
            
            request.setAttribute("pageNow", pageNo);
            request.setAttribute("pagePrev", pagePrev);
            request.setAttribute("pageNext", pageNext);
            request.setAttribute("pageCount", pageCount);
            request.setAttribute("cars",list);
        } catch (Exception e) {
            // TODO 自动生成的 catch 块
            e.printStackTrace();
        }
        //跳转
        request.getRequestDispatcher("index.jsp").forward(request, response);
    }

    /**
     * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
     */
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // TODO Auto-generated method stub
        doGet(request, response);
    }

}

index.jsp内容如下：

<%@page import="com.bean.Car"%>
<%@page import="java.util.ArrayList"%>
<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
<script>
function a(){
    document.getElementById("ff").submit();
}
</script>
</head>
<body>
<h1>显示分页</h1>
<%
ArrayList<Car> list =(ArrayList<Car>)request.getAttribute("cars");
for(Car c : list){
%>
<div>
<span style="100px; display:inline-block;"><%=c.getCode() %></span>
<span style="300px; display:inline-block;"><%=c.getName() %></span>
<span style="100px; display:inline-block;"><%=c.getOil() %></span>
</div>
<%
}
%>
<%--分页内容 --%>
<a href="show?pg=1">首页</a>
<a href="show?pg=<%=request.getAttribute("pagePrev") %>">上一页</a>
<%
int pageCount = (int)request.getAttribute("pageCount");
for(int i=1; i<=pageCount;i++){
%>
<a href="show?pg=<%=i %>"><%=i %></a>
<%
}
%>
<a href="show?pg=<%=request.getAttribute("pageNext") %>">下一页</a>
<a href="show?pg=<%=pageCount%>">末页</a>
<form id="ff" method="get" action="show">
    <select name="pg" onchange="a()">
    <%
    for(int i=1;i<=pageCount;i++){
        int p = (int)request.getAttribute("pageNow");
        if(p==i){
    %>
        <option value="<%=i %>" selected="selected"><%=i %></option>
    <%
        }
        else{    
    %>    
        <option value="<%=i %>" ><%=i %></option>
    <%
        }
    }
    %>
    </select>
    <%-- <input type="submit" value="GO"/>--%>
</form>
</body>
</html>

显示如下：