分页查询功能

标签：功能 rows 分页 int list 查询 import currentPage public

分页查询功能-分析

分析：

 

 

 分页查询功能-代码实现-分页具体步骤

 

 

 分页查询功能-代码实现-后台代码实现

创建PageBean类

package com.jstl.domain;

import java.util.List;

/**
 * 分页对象
 */
public class PageBean<T> {
    private int totalCount; // 总记录数
    private int totlePage;  // 总页码
    private List<T> list;   // 每页的数据
    private int currenPage; // 当前页面
    private int rows;       //每页显示的记录数

    @Override
    public String toString() {
        return "PageBean{" +
                "totalCount=" + totalCount +
                ", totlePage=" + totlePage +
                ", list=" + list +
                ", currenPage=" + currenPage +
                ", rows=" + rows +
                '}';
    }

    public int getTotalCount() {
        return totalCount;
    }

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

    public int getTotlePage() {
        return totlePage;
    }

    public void setTotlePage(int totlePage) {
        this.totlePage = totlePage;
    }

    public List<T> getList() {
        return list;
    }

    public void setList(List<T> list) {
        this.list = list;
    }

    public int getCurrenPage() {
        return currenPage;
    }

    public void setCurrenPage(int currenPage) {
        this.currenPage = currenPage;
    }

    public int getRows() {
        return rows;
    }

    public void setRows(int rows) {
        this.rows = rows;
    }
}

UserDao创建两个方法

    /**
     * 查询总记录数
     * @return
     */
    int findTotalCount();

    /**
     * 分页查询每页记录
     * @param start
     * @param rows
     * @return
     */
    List<User> findByPage(int start,int rows);

UserDaoImpl重写方法

    @Override
    public int findTotalCount() {
        // 1.定义模板初始化sql
        String sql = "select count(*) from user where 1 = 1";
        return template.queryForObject(sql,Integer.class);
    }

    @Override
    public List<User> findByPage(int start, int rows) {
        String sql = "select * from user where 1 = 1";
        return template.query(sql,new BeanPropertyRowMapper<User>(User.class),start,rows);
    }

UserService创建方法

PageBean<User> findUserByPage(String currentPage,String rows);

UserServiceImpl重写方法

@Override
    public PageBean<User> findUserByPage(String _currentPage, String _rows) {
        int currentPage = Integer.parseInt(_currentPage);
        int rows = Integer.parseInt(_rows);

        if (currentPage <= 0) {
            currentPage = 1;
        }
        // 1.创建空的PageBean对象
        PageBean<User> pb = new PageBean<>();
        // 2.设置参数
        pb.setCurrenPage(currentPage);
        pb.setRows(rows);

        // 3.调用dao查询总记录数
        int totalCount = dao.findTotalCount();
        pb.setRows(totalCount);
        // 4.调用dao查询List集合
        // 计算开始的记录索引
        int start = (currentPage - 1) * rows;
        List<User> list = dao.findByPage(start, rows);
        pb.setList(list);

        // 5.计算总页码
        int totalPage = (totalCount % rows) == 0 ? totalCount / rows : (totalCount / rows) + 1;
        pb.setTotlePage(totalPage);

        return pb;
    }

新建FindUserByPageServlet类

package com.jstl.web.servlet;

import com.jstl.domain.PageBean;
import com.jstl.domain.User;
import com.jstl.service.impl.UserServiceImpl;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;

@WebServlet("/findUserByPageServlet ")
public class FindUserByPageServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        // 获取参数
        String currentPage = request.getParameter("currentPage");
        String rows = request.getParameter("rows");

        // 调用service查询
        UserServiceImpl userService = new UserServiceImpl();
        PageBean<User> pd = userService.findUserByPage(currentPage, rows);

        System.out.println(pd);
        // 将PageBean存入request
        request.setAttribute("pd",pd);
        // 转发list.jsp
        request.getRequestDispatcher("/list.jsp").forward(request,response);
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

分页查询功能-代码实现-前台代码实现

修改FindUserByPageServlet

package com.jstl.web.servlet;

import com.jstl.domain.PageBean;
import com.jstl.domain.User;
import com.jstl.service.impl.UserServiceImpl;

import javax.servlet.*;
import javax.servlet.http.*;
import javax.servlet.annotation.*;
import java.io.IOException;

@WebServlet("/findUserByPageServlet ")
public class FindUserByPageServlet extends HttpServlet {
    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        //获取参数
        String currentPage = req.getParameter("currentPage");
        String rows = req.getParameter("rows");

        if(currentPage == null || "".equals(currentPage)){

            currentPage = "1";
        }
        if(rows == null || "".equals(rows)){
            rows = "5";
        }

        //调用service查询
        UserServiceImpl userService = new UserServiceImpl();
        PageBean<User> pd = userService.findUserByPage(currentPage,rows);

        System.out.println(pd);
        //将PageBean存入request
        req.setAttribute("pd",pd);
        //转发到list.jsp
        req.getRequestDispatcher("/list.jsp").forward(req,resp);
    }

    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

修改list.jsp

<%@ page contentType="text/html;charset=UTF-8" language="java" %>

<%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core" %>

<!DOCTYPE html>
<!-- 网页使用的语言 -->
<html lang="zh-CN">
<head>
    <!-- 指定字符集 -->
    <meta charset="utf-8">
    <!-- 使用Edge最新的浏览器的渲染方式 -->
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <!-- viewport视口：网页可以根据设置的宽度自动进行适配，在浏览器的内部虚拟一个容器，容器的宽度与设备的宽度相同。
    width: 默认宽度与设备的宽度相同
    initial-scale: 初始的缩放比，为1:1 -->
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <!-- 上述3个meta标签*必须*放在最前面，任何其他内容都*必须*跟随其后！ -->
    <title>用户信息管理系统</title>

    <!-- 1. 导入CSS的全局样式 -->
    <link href="css/bootstrap.min.css" rel="stylesheet">
    <!-- 2. jQuery导入，建议使用1.9以上的版本 -->
    <script src="js/jquery-2.1.0.min.js"></script>
    <!-- 3. 导入bootstrap的js文件 -->
    <script src="js/bootstrap.min.js"></script>
    <style type="text/css">
        td, th {
            text-align: center;
        }
    </style>

    <script>
        function deleteUser(id){
            //用户安全提示
            if(confirm("您确定要删除吗？")){
                //访问路径
                location.href="${pageContext.request.contextPath}/delUserServlet?id="+id;
            }
        }

        window.onload = function(){
            //给删除选中按钮添加单击事件
            document.getElementById("delSelected").onclick = function(){
                if(confirm("您确定要删除选中条目吗？")){

                   var flag = false;
                    //判断是否有选中条目
                    var cbs = document.getElementsByName("uid");
                    for (var i = 0; i < cbs.length; i++) {
                        if(cbs[i].checked){
                            //有一个条目选中了
                            flag = true;
                            break;
                        }
                    }

                    if(flag){//有条目被选中
                        //表单提交
                        document.getElementById("form").submit();
                    }

                }

            }
            //1.获取第一个cb
            document.getElementById("firstCb").onclick = function(){
                //2.获取下边列表中所有的cb
                var cbs = document.getElementsByName("uid");
                //3.遍历
                for (var i = 0; i < cbs.length; i++) {
                    //4.设置这些cbs[i]的checked状态 = firstCb.checked
                    cbs[i].checked = this.checked;

                }

            }


        }


    </script>
</head>
<body>
<div class="container">
    <h3 style="text-align: center">用户信息列表</h3>

    <div style="float: left;">

        <form class="form-inline" action="${pageContext.request.contextPath}/findUserByPageServlet" method="post">
            <div class="form-group">
                <label for="exampleInputName2">姓名</label>
                <input type="text" name="name" value="${condition.name[0]}" class="form-control" id="exampleInputName2" >
            </div>
            <div class="form-group">
                <label for="exampleInputName3">籍贯</label>
                <input type="text" name="address" value="${condition.address[0]}" class="form-control" id="exampleInputName3" >
            </div>

            <div class="form-group">
                <label for="exampleInputEmail2">邮箱</label>
                <input type="text" name="email" value="${condition.email[0]}" class="form-control" id="exampleInputEmail2"  >
            </div>
            <button type="submit" class="btn btn-default">查询</button>
        </form>

    </div>

    <div style="float: right;margin: 5px;">

        <a class="btn btn-primary" href="${pageContext.request.contextPath}/add.jsp">添加联系人</a>
        <a class="btn btn-primary" href="javascript:void(0);" id="delSelected">删除选中</a>

    </div>
    <form id="form" action="${pageContext.request.contextPath}/delSelectedServlet" method="post">
        <table border="1" class="table table-bordered table-hover">
        <tr class="success">
            <th><input type="checkbox" id="firstCb"></th>
            <th>编号</th>
            <th>姓名</th>
            <th>性别</th>
            <th>年龄</th>
            <th>籍贯</th>
            <th>QQ</th>
            <th>邮箱</th>
            <th>操作</th>
        </tr>

        <c:forEach items="${pb.list}" var="user" varStatus="s">
            <tr>
                <td><input type="checkbox" name="uid" value="${user.id}"></td>
                <td>${s.count}</td>
                <td>${user.name}</td>
                <td>${user.gender}</td>
                <td>${user.age}</td>
                <td>${user.address}</td>
                <td>${user.qq}</td>
                <td>${user.email}</td>
                <td><a class="btn btn-default btn-sm" href="${pageContext.request.contextPath}/findUserServlet?id=${user.id}">修改</a> 
                    <a class="btn btn-default btn-sm" href="javascript:deleteUser(${user.id});">删除</a></td>
            </tr>

        </c:forEach>


    </table>
    </form>
    <div>
        <nav aria-label="Page navigation">
            <ul class="pagination">
                <c:if test="${pb.currentPage == 1}">
                    <li class="disabled">
                </c:if>

                <c:if test="${pb.currentPage != 1}">
                    <li>
                </c:if>


                    <a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage - 1}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}" aria-label="Previous">
                        <span aria-hidden="true">«</span>
                    </a>
                </li>


                <c:forEach begin="1" end="${pb.totalPage}" var="i" >


                    <c:if test="${pb.currentPage == i}">
                        <li class="active "><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}">${i}</a></li>
                    </c:if>
                    <c:if test="${pb.currentPage != i}">
                        <li><a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${i}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}">${i}</a></li>
                    </c:if>

                </c:forEach>


                <li>
                    <a href="${pageContext.request.contextPath}/findUserByPageServlet?currentPage=${pb.currentPage + 1}&rows=5&name=${condition.name[0]}&address=${condition.address[0]}&email=${condition.email[0]}" aria-label="Next">
                        <span aria-hidden="true">»</span>
                    </a>
                </li>
                <span style="font-size: 25px;margin-left: 5px;">
                    共${pb.totalCount}条记录，共${pb.totalPage}页
                </span>

            </ul>
        </nav>
    </div>

</div>

</body>
</html>

标签：功能,rows,分页,int,list,查询,import,currentPage,public
From： https://www.cnblogs.com/wsfj/p/17115432.html