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JavaWeb项目开发 | 分页

发表于 2022-01-12 分类于 Java ， JavaWeb项目开发，分页

分页

项目目录

创建表

分页后台实现

paging.jsp(发出分页查询请求)

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    <a href="/paging/page?pageNumber=1">分页查询</a>
</body>
</html>

PageServlet.java(处理请求)

package com.oracle.servlet;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.oracle.bean.PageBean;
import com.oracle.service.PageService;

public class PageServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        //获取前台传递的当前页
        String pn = request.getParameter("pageNumber");
        int pageNumber = Integer.parseInt(pn);
        int pageSize = 2;
        
        PageService ps = new PageService();
        PageBean pb = ps.getPageBean(pageNumber, pageSize);
        
        //把pb放入request域对象中
        request.setAttribute("pb", pb);
        //请求转发到前台页面
        request.getRequestDispatcher("/paging1.jsp").forward(request, response);
    }

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

PageService.java(编写业务逻辑)

package com.oracle.service;

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

import com.oracle.bean.PageBean;
import com.oracle.bean.Product;
import com.oracle.dao.PageDao;

public class PageService {

    public PageBean getPageBean(int pageNumber, int pageSize) {
        PageBean pb = null;
        try {
            // TODO Auto-generated method stub
            PageDao pd = new PageDao();
            
            //组装PageBean
            pb = new PageBean(pageSize, pageNumber);
            
            //查询当前页显示的数据
            List<Product> list = pd.getProList(pb);
            
            //查询总条数
            int count = pd.getCount();
            
            //把数据放如pagebean中
            pb.setList(list);
            pb.setTotalSize(count);
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        
        return pb;
    }
}

PageDao.java(操作数据库)

package com.oracle.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 com.oracle.bean.PageBean;
import com.oracle.bean.Product;
import com.oracle.utils.DataSourceUtils;

public class PageDao {

    public List<Product> getProList(PageBean pb) throws SQLException {
        // TODO Auto-generated method stub
        QueryRunner qr = new QueryRunner(DataSourceUtils.getDataSource());
        
        String sql = "select * from product limit ?,?";
        List<Product> list = qr.query(sql, new BeanListHandler<>(Product.class), pb.getIndex(), pb.getPageSize());
        return list;
    }

    public int getCount() throws SQLException {
        // TODO Auto-generated method stub
        QueryRunner qr = new QueryRunner(DataSourceUtils.getDataSource());
        
        String sql = "select coutn(*) from product";
        
        int count = ((Long)qr.query(sql, new ScalarHandler())).intValue();
        
        return count;
    }

}

分页前台实现

paging1.jsp(展示分页查询结果)

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Insert title here</title>
</head>
<body>
    <table border="1px" width="60%" height="200px" align="center">
        <tr>
            <th>商品id</th>
            <th>商品名称</th>
            <th>商品价格</th>
            <th>商品描述</th>
        </tr>
        
        <c:forEach items="${pb.list}" var="pro">
            <tr>
                <td>${pro.id}</td>
                <td>${pro.pname}</td>
                <td>${pro.price}</td>
                <td>${pro.pdesc}</td>
            </tr>
        </c:forEach>
    </table>
    
    <center>
        <c:forEach begin="1" end="${pb.totalCount}" step="1" var="n">
            <a href="/paging/page?pageNumber=${n}">${n}</a>
        </c:forEach>
    </center>
</body>
</html>

效果