手写Java分页模块

web层的servlet

 1 package web;
 2 
 3 import java.io.IOException;
 4 import java.sql.SQLException;
 5 import java.util.List;
 6 
 7 import javax.servlet.ServletException;
 8 import javax.servlet.http.HttpServlet;
 9 import javax.servlet.http.HttpServletRequest;
10 import javax.servlet.http.HttpServletResponse;
11 
12 import domain.Product;
13 import service.ProductService;
14 import vo.PageBean;
15 
16 public class ProductListServlet extends HttpServlet {
17 
18     public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
19         ProductService service = new ProductService();
20         //        模拟当前页为1
21         String currentPageStr = request.getParameter("currentPage");
22         if(currentPageStr==null)currentPageStr="1";
23         int currentPage=Integer.parseInt(currentPageStr);
24         //        模拟每页显示12条
25         int currentCount=12;
26         PageBean<Product> pageBean =null;
27         try {
28             pageBean = service.findPageBean(currentPage,currentCount);
29         } catch (SQLException e) {
30             e.printStackTrace();
31         }
32         /**
33          * 当前页面：currentPage
34          * 当前页面的条数:current
35          * 数据总页数：totalPage
36          * 数据总条数：totalCount
37          * 每页数据集合：productList
38          */
39             
40         request.setAttribute("pageBean", pageBean);
41         request.getRequestDispatcher("/product_list.jsp").forward(request, response);
42         
43         
44     }
45 
46     public void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
47         doGet(request, response);
48     }
49 }

　　service层

 1 package service;
 2 
 3 import java.sql.SQLException;
 4 import java.util.ArrayList;
 5 import java.util.List;
 6 
 7 import dao.ProductDao;
 8 import domain.Product;
 9 import vo.PageBean;
10 
11 public class ProductService {
12 
13     public List<Product> findAllProduct() throws SQLException {
14     ProductDao dao = new ProductDao();
15     
16         return dao.findAllProduct();
17     }
18 
19     public PageBean findPageBean(int currentPage,int currentCount) throws SQLException {
20         ProductDao dao = new ProductDao();
21         
22         //想办法封装pageBean并返回
23         PageBean pageBean = new PageBean();
24         //1.当前页    private int currentPage;
25         pageBean.setCurrentPage(currentPage);
26         
27         //2.当前显示条数   private int currentCount;
28         pageBean.setCurrentCount(currentCount);
29         //3.总条数    private     int totalCount;
30         int totalCount = dao.getTotalCount();
31         pageBean.setTotalCount(totalCount);
32         //4.总页数    private int totalPage;
33         int totalPage = (int)Math.ceil(1.0*totalCount/currentCount);
34         pageBean.setTotalPage(totalPage);
35         //5.从第几条数据开始     int index
36         int index = (currentPage-1)*currentCount;
37         //6.每页显示的数据      private List<T> productList = new ArrayList();
38         List<Product> productList = dao.findProductListForPageBean(index,currentCount); 
39         pageBean.setProductList(productList);
40     
41         return pageBean;
42     }
43 
44 }

　　dao层

package dao;

import java.sql.SQLException;
import java.util.List;

import org.apache.commons.dbutils.QueryRunner;
import org.apache.commons.dbutils.handlers.BeanListHandler;
import org.apache.commons.dbutils.handlers.ScalarHandler;

import domain.Product;
import utils.MyDataSourceUtils;

public class ProductDao {

    public List<Product> findAllProduct() throws SQLException {
    return new QueryRunner(MyDataSourceUtils.getDataSource()).query("select * from product",new BeanListHandler<Product>(Product.class));
        
    }
    //    获得全部商品条数
    public int getTotalCount() throws SQLException {
        QueryRunner runner = new QueryRunner(MyDataSourceUtils.getDataSource());
        String sql = "select count(*) from product";
        Long query = (Long)runner.query(sql,new ScalarHandler());
        return query.intValue();
    }
    //获取分页的商品数据
    public List<Product> findProductListForPageBean(int index,int currentCount) throws SQLException {
        QueryRunner runner = new QueryRunner(MyDataSourceUtils.getDataSource());
        String sql = "select * from product limit ?,?";
        List<Product> productList=runner.query(sql, new BeanListHandler<Product>(Product.class),index,currentCount);        
        return productList;
    }

}

　　jsp页面

  1 <%@ page language="java" contentType="text/html; charset=UTF-8"
  2     pageEncoding="UTF-8"%>
  3 <%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c"%>
  4 <!DOCTYPE html>
  5 <html>
  6 <head>
  7 <meta name="viewport" content="width=device-width, initial-scale=1">
  8 <title>会员登录</title>
  9 <link rel="stylesheet" href="css/bootstrap.min.css" type="text/css" />
 10 <script src="js/jquery-1.11.3.min.js" type="text/javascript"></script>
 11 <script src="js/bootstrap.min.js" type="text/javascript"></script>
 12 <!-- 引入自定义css文件 style.css -->
 13 <link rel="stylesheet" href="css/style.css" type="text/css" />
 14 
 15 <style>
 16 body {
 17     margin-top: 20px;
 18     margin: 0 auto;
 19      100%;
 20 }
 21 
 22 .carousel-inner .item img {
 23      100%;
 24     height: 300px;
 25 }
 26 </style>
 27 </head>
 28 
 29 <body>
 30 
 31 
 32     <!-- 引入header.jsp -->
 33     <jsp:include page="/header.jsp"></jsp:include>
 34 
 35 
 36     <div class="row" style=" 1210px; margin: 0 auto;">
 37         <div class="col-md-12">
 38             <ol class="breadcrumb">
 39                 <li><a href="#">首页</a></li>
 40             </ol>
 41         </div>
 42         <c:forEach items="${pageBean.productList}" var="product">
 43             <div class="col-md-2" style="height:250px">
 44                 <a href="product_info.htm"> <img
 45                     src="${pageContext.request.contextPath}/${product.pimage}"
 46                     width="170" height="170" style="display: inline-block;">
 47                 </a>
 48                 <p>
 49                     <a href="product_info.html" style='color: green'>${product.pname}</a>
 50                 </p>
 51                 <p>
 52                     <font color="#FF0000">商城价：&yen;${product.shop_price}</font>
 53                 </p>
 54             </div>
 55 
 56 
 57 
 58         </c:forEach>
 59         
 60 
 61         
 62 
 63     </div>
 64 
 65     <!--分页 -->
 66     <div style=" 380px; margin: 0 auto; margin-top: 50px;">
 67         <ul class="pagination" style="text-align: center; margin-top: 10px;">
 68             
 69             <c:if test="${pageBean.currentPage==1 }">
 70                 <li class="disabled">
 71                     <a href="javascript:void(0);" aria-label="Previous">
 72                         <span aria-hidden="true">&laquo;</span>
 73                     </a>
 74                 </li>
 75             </c:if>
 76             
 77             <c:if test="${pageBean.currentPage!=1 }">
 78                 <li >
 79                     <a href="${pageContext.request.contextPath }/productList?currentPage=${pageBean.currentPage-1}" aria-label="Previous">
 80                         <span aria-hidden="true">&laquo;</span>
 81                     </a>
 82                 </li>
 83             </c:if>
 84             
 85             <c:forEach begin="1" end="${pageBean.totalPage}" var="page">
 86                 <c:if test="${page!=pageBean.currentPage}">
 87                     <li><a href="${pageContext.request.contextPath }/productList?currentPage=${page}">${page}</a></li>
 88                 </c:if> 
 89                 <c:if test="${page==pageBean.currentPage}">
 90                     <li class="active"><a href="javascript:void(0);">${page}</a></li>
 91                 </c:if>
 92                 
 93             </c:forEach>
 94             <c:if test="${pageBean.currentPage!=pageBean.totalPage}">
 95                 <li>
 96                     <a href="${pageContext.request.contextPath }/productList?currentPage=${pageBean.currentPage+1}" aria-label="Next"> 
 97                         <span aria-hidden="true">&raquo;</span>
 98                     </a>
 99                 </li>
100             </c:if>
101             <c:if test="${pageBean.currentPage==pageBean.totalPage}">
102                 <li class="disabled">
103                     <a href="javascript:void(0);" aria-label="Next"> 
104                         <span aria-hidden="true">&raquo;</span>
105                     </a>
106                 </li>
107             </c:if>
108             
109             
110             
111             
112             <!-- <li class="disabled"><a href="#" aria-label="Previous"><span
113                     aria-hidden="true">&laquo;</span></a></li>
114             <li class="active"><a href="#">1</a></li>
115             <li><a href="#">2</a></li>
116             <li><a href="#">3</a></li>
117             <li><a href="#">4</a></li>
118             <li><a href="#">5</a></li>
119             <li><a href="#">6</a></li>
120             <li><a href="#">7</a></li>
121             <li><a href="#">8</a></li>
122             <li><a href="#">9</a></li>
123             <li><a href="#" aria-label="Next"> <span aria-hidden="true">&raquo;</span>
124             </a></li> -->
125         </ul>
126     </div>
127     <!-- 分页结束 -->
128 
129     <!--商品浏览记录-->
130     <div
131         style=" 1210px; margin: 0 auto; padding: 0 9px; border: 1px solid #ddd; border-top: 2px solid #999; height: 246px;">
132 
133         <h4 style=" 50%; float: left; font: 14px/30px 微软雅黑">浏览记录</h4>
134         <div style=" 50%; float: right; text-align: right;">
135             <a href="">more</a>
136         </div>
137         <div style="clear: both;"></div>
138 
139         <div style="overflow: hidden;">
140 
141             <ul style="list-style: none;">
142                 <li
143                     style=" 150px; height: 216; float: left; margin: 0 8px 0 0; padding: 0 18px 15px; text-align: center;"><img
144                     src="products/1/cs10001.jpg" width="130px" height="130px" /></li>
145             </ul>
146 
147         </div>
148     </div>
149 
150 
151     <!-- 引入footer.jsp -->
152     <jsp:include page="/footer.jsp"></jsp:include>
153 
154 </body>
155 
156 </html>

pagebean

package vo;

import java.util.ArrayList;
import java.util.List;

import domain.Product;

public class PageBean<T> {
    //当前页
    private int currentPage;
    //当前显示条数
    private int currentCount;
    
    
    //总页数
    private int totalPage;
    //总条数
    private int totalCount;
    
    
    //每页显示的数据
    private List<T> productList = new ArrayList();


    public int getCurrentPage() {
        return currentPage;
    }


    public void setCurrentPage(int currentPage) {
        this.currentPage = currentPage;
    }


    public int getCurrentCount() {
        return currentCount;
    }


    public void setCurrentCount(int currentCount) {
        this.currentCount = currentCount;
    }


    public int getTotalPage() {
        return totalPage;
    }


    public void setTotalPage(int totalPage) {
        this.totalPage = totalPage;
    }


    public int getTotalCount() {
        return totalCount;
    }


    public void setTotalCount(int totalCount) {
        this.totalCount = totalCount;
    }


    public List<T> getProductList() {
        return productList;
    }


    public void setProductList(List<T> productList) {
        this.productList = productList;
    }
    
    
    
    
}