jsp+mysql实现网页的分页查询
更新时间:2022-07-23 03:40:08 作者:佚名 我要评论(0)
本文实例为大家分享了jsp+mysql实现网页的分页查询的具体代码,供大家参考,具体内容如下
一、实现分页查询的核心sql语句
(1)查询数据库的
一、实现分页查询的核心sql语句
(1)查询数据库的
本文实例为大家分享了jsp+mysql实现网页的分页查询的具体代码,供大家参考,具体内容如下
一、实现分页查询的核心sql语句
(1)查询数据库的记录总数的sql语句:
select count(*) from +(表名);
(2)每次查询的记录数的sql语句:
其中:0是搜索的索引,2是每次查找的条数。
select * from 表名 limit 0,2;
二、代码实现
*上篇写过这两个类 , DBconnection类:用于获取数据库连接,Author对象类。这两个类的代码点击连接查看。点击链接查看 DBconnection类和Author对象类
(1)登录页面:index.jsp。
<%@ 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="AuthorListPageServlet">用户列表分页查询</a> </body> </html>
(2)显示页面:userlistpage.jsp。
<%@ 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>查询页面</title> </head> <body> <table border="1"> ? <tr> ? ? <td>编号</td> ? ? <td>名称</td> ? ? <td>价格</td> ? ? <td>数量</td> ? ? <td>日期</td> ? ? <td>风格</td> ? </tr> ? <c:forEach items="${pageBean.list}" var="author"> ? <tr> ? ? <td>${author.id}</td> ? ? <td>${author.name }</td> ? ? <td>${author.price }</td> ? ? <td>${author.num }</td> ? ? <td>${author.dates}</td> ? ? <td>${author.style}</td> ? </tr> ? </c:forEach> </table> <c:if test="${ pageBean.record>0}"> <div> ? ? ?? ? ? ? <c:if test="${pageBean.currentPage <= 1}"> ? ? ? <span>首页</span> ? ? ? <span>上一页</span> ? ? ? <a href ="AuthorListPageServlet?currPage=${pageBean.currentPage + 1 }">下一页</a> ? ? ? <a href ="AuthorListPageServlet?currPage=${pageBean.totalPage }">尾页</a> ? ? ? </c:if> ? ? ?? ? ? ? <c:if test="${pageBean.currentPage > 1 && pageBean.currentPage < pageBean.totalPage ?}"> ? ? ? ?<a href ="AuthorListPageServlet?currPage=1">首页</a> ? ? ? <a href ="AuthorListPageServlet?currPage=${pageBean.currentPage - 1 }">上一页</a> ? ? ? <a href ="AuthorListPageServlet?currPage=${pageBean.currentPage + 1 }">下一页</a> ? ? ? <a href ="AuthorListPageServlet?currPage=${pageBean.totalPage }">尾页</a> ? ? ? </c:if> ? ? ? ? ? ?<c:if test="${ pageBean.currentPage >= pageBean.totalPage}"> ? ? ? <a href ="AuthorListPageServlet?currPage=1">首页</a> ? ? ? <a href ="AuthorListPageServlet?currPage=${pageBean.currentPage - 1 }">上一页</a> ? ? ?<span>下一页</span> ? ? ?<span>尾页</span> ? ? ?</c:if> </div> </c:if> </body> </html>
(3)功能实现:AuthorDao.java。
package com.dao; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.entity.Author; public class AuthorDao { ?? ? ?? ? public ?Author check(String username ,int ?password ) { ?? ??? ?? ?? ??? ? Author obj = null ; ?? ??? ? try { ?? ??? ??? ?DBConnection db = new DBConnection(); ?? ??? ??? ?//获取数据库连接 ?? ??? ??? ?Connection conn = db.getConn(); ?? ??? ??? ? ?? ??? ??? ?String sql="select *from furnitures where name = ? and id = ?"; ?? ??? ??? ? ?? ??? ??? ?PreparedStatement ps=conn.prepareStatement(sql); ?? ??? ??? ?//设置用户名和密码作为参数放入sql语句 ?? ??? ??? ?ps.setString(1,username); ?? ??? ??? ?ps.setInt(2,password); ?? ??? ??? ?//执行查询语句 ?? ??? ??? ?ResultSet rs = ps.executeQuery(); ?? ??? ??? ?//用户名和密码正确,查到数据 ?欧式风格 ?茶几 ?? ??? ??? ?if(rs.next()) { ?? ??? ??? ??? ?obj = new Author(); ?? ??? ??? ??? ?obj.setId(rs.getInt(1)); ?? ??? ??? ??? ?obj.setName(rs.getString(2)); ?? ??? ??? ??? ?obj.setPrice(rs.getInt(3)); ?? ??? ??? ??? ?obj.setNum(rs.getInt(4)); ?? ??? ??? ??? ?obj.setDates(rs.getString(5)); ?? ??? ??? ??? ?obj.setStyle(rs.getString(6)); ?? ??? ??? ?} ?? ??? ?} catch (SQLException e) { ?? ??? ??? ?// TODO Auto-generated catch block ?? ??? ??? ?e.printStackTrace(); ?? ??? ?} ?? ??? ? return obj; ?? ? } ?? ? /** ?? ? ?* 用户列表信息查询 ?? ? ?* @return ?? ? ?*/ ?? ? public List<Author> queryAuthorList(){ ?? ??? ? Author obj = null ; ?? ??? ? List<Author> list = new ArrayList<Author>(); ?? ??? ? try { ?? ??? ??? ?DBConnection db = new DBConnection(); ?? ??? ??? ?//获取数据库连接 ?? ??? ??? ?Connection conn = db.getConn(); ?? ??? ??? ? ?? ??? ??? ?String sql="select *from furnitures"; ?? ??? ??? ? ?? ??? ??? ?PreparedStatement ps=conn.prepareStatement(sql); ?? ? ?? ??? ??? ?//执行查询语句 ?? ??? ??? ?ResultSet rs = ps.executeQuery(); ?? ??? ??? ?//用户名和密码正确,查到数据 ?欧式风格 ?茶几 ?? ??? ??? ?//循环遍历获取用户信息 ?? ??? ??? ?while(rs.next()) { ?? ??? ??? ??? ? ?? ??? ??? ??? ?obj = new Author(); ?? ??? ??? ??? ?obj.setId(rs.getInt(1)); ?? ??? ??? ??? ?obj.setName(rs.getString(2)); ?? ??? ??? ??? ?obj.setPrice(rs.getInt(3)); ?? ??? ??? ??? ?obj.setNum(rs.getInt(4)); ?? ??? ??? ??? ?obj.setDates(rs.getString(5)); ?? ??? ??? ??? ?obj.setStyle(rs.getString(6)); ?? ??? ??? ??? ?//将对象加入list里边 ?? ??? ??? ??? ?list.add(obj); ?? ??? ??? ?} ?? ??? ?} catch (SQLException e) { ?? ??? ??? ?// TODO Auto-generated catch block ?? ??? ??? ?e.printStackTrace(); ?? ??? ?} ?? ??? ? return list; ?? ? } ?? ?? ?? ?? ?? ? /** ?? ? ?* 查询用户表总记录数 ?? ? ?* @return ?? ? ?*/ ?? ? public int queryUserListCount() { ?? ??? ? DBConnection db; ?? ??? ?try { ?? ??? ? ? ? db = new DBConnection(); ?? ??? ??? ? Connection conn = db.getConn(); ?? ??? ??? ? String sql = "select count(*) from furnitures"; ?? ??? ??? ?? ?? ??? ??? ? PreparedStatement ps = conn.prepareStatement(sql); ?? ??? ??? ? ResultSet rs = ps.executeQuery(); ?? ??? ??? ?? ?? ??? ??? ?? ?? ??? ??? ? if(rs.next()) { ?? ??? ??? ??? ? return rs.getInt(1); ?? ??? ??? ? } ?? ??? ??? ?? ?? ??? ??? ?? ?? ??? ?} catch (SQLException e) { ?? ??? ??? ?// TODO Auto-generated catch block ?? ??? ??? ?e.printStackTrace(); ?? ??? ?} ?? ??? ? ?? ??? ? return 0; ?? ? } ?? ? /** ?? ? ?* 查询用户分页数据 ?? ? ?* @param pageIndex数据起始索引 ?? ? ?* @param pageSize每页显示条数 ?? ? ?* @return ?? ? ?*/ ?? ? public List<Author>queryUserListPage(int pageIndex,int pageSize){ ?? ??? ?? ?? ??? ? Author obj = null; ?? ??? ? List<Author> list = new ArrayList<Author>(); ?? ??? ?? ?? ??? ? try { ?? ??? ??? ?Connection conn = new DBConnection().getConn(); ?? ??? ??? ?String sql = "select * from furnitures limit ?,?;"; ?? ??? ??? ?PreparedStatement ps = conn.prepareStatement(sql); ?? ??? ??? ?ps.setObject(1, pageIndex); ?? ??? ??? ?ps.setObject(2,pageSize); ?? ??? ??? ? ?? ??? ??? ?ResultSet rs = ps.executeQuery(); ?? ??? ??? ?//遍历结果集获取用户列表数据 ?? ??? ??? ? ?? ??? ??? ?while(rs.next()) { ?? ??? ??? ??? ?obj = new Author(); ?? ??? ??? ??? ? ?? ??? ??? ??? ?obj.setId(rs.getInt(1)); ?? ??? ??? ??? ?obj.setName(rs.getString(2)); ?? ??? ??? ??? ?obj.setPrice(rs.getInt(3)); ?? ??? ??? ??? ?obj.setNum(rs.getInt(4)); ?? ??? ??? ??? ?obj.setDates(rs.getString(5)); ?? ??? ??? ??? ?obj.setStyle(rs.getString(6)); ?? ??? ??? ??? ? ?? ??? ??? ??? ?list.add(obj); ?? ??? ??? ?} ?? ??? ?} catch (SQLException e) { ?? ??? ??? ?// TODO Auto-generated catch block ?? ??? ??? ?e.printStackTrace(); ?? ??? ?} ?? ??? ? return list; ?? ? } ?? ? /** ?? ? ?* 用户新增 ?? ? ?* @param obj ?? ? ?*/ ?? ? public void add(Author obj) { ?? ??? ? ?? ??? ?try { ?? ??? ??? ? ?? ??? ??? ?DBConnection db = new DBConnection(); ?? ??? ??? ?//获取数据库连接 ?? ??? ??? ?Connection conn = db.getConn(); ?? ??? ??? ? ?? ??? ??? ?String sql="insert into furnitures values(id,?,?,?,?,?)"; ?? ??? ??? ? ?? ??? ??? ?PreparedStatement ps=conn.prepareStatement(sql); ?? ??? ??? ?ps.setObject(1, obj.getName()); ?? ??? ??? ?ps.setObject(2, obj.getPrice()); ?? ??? ??? ?ps.setObject(3, obj.getNum()); ?? ??? ??? ?ps.setObject(4,obj.getDates()); ?? ??? ??? ?ps.setObject(5, obj.getStyle()); ?? ??? ??? ? ?? ??? ??? ?//执行sql语句 ?? ??? ? ? ps.execute(); ?? ??? ? ?? ?? ??? ??? ? ?? ??? ?} catch (SQLException e) { ?? ??? ??? ?// TODO Auto-generated catch block ?? ??? ??? ?e.printStackTrace(); ?? ??? ?} ?? ??? ??? ? ?? ? } ?? ? //删除用户 ?? ? public void del(int id) { ?? ??? ? try { ?? ??? ??? ??? ? ?? ??? ??? ??? ?DBConnection db = new DBConnection(); ?? ??? ??? ??? ?//获取数据库连接 ?? ??? ??? ??? ?Connection conn = db.getConn(); ?? ??? ??? ??? ? ?? ??? ??? ??? ?String sql="delete from furnitures where id = ?"; ?? ??? ??? ??? ? ?? ??? ??? ??? ?PreparedStatement ps=conn.prepareStatement(sql); ?? ??? ??? ??? ? ?? ??? ??? ??? ?ps.setObject(1, id); ?? ??? ??? ??? ? ?? ??? ??? ??? ?//执行sql语句 ?? ??? ??? ? ? ps.execute(); ?? ??? ??? ? ?? ?? ??? ??? ??? ? ?? ??? ??? ?} catch (SQLException e) { ?? ??? ??? ??? ?// TODO Auto-generated catch block ?? ??? ??? ??? ?e.printStackTrace(); ?? ??? ??? ?} ?? ??? ??? ??? ? ?? ? } ?? ? }
(4)交互层:AuthorListPageServlet.java。
package com.servlet; import java.io.IOException; import java.util.List; 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.dao.AuthorDao; import com.entity.Author; import com.util.PageBean; /** ?* Servlet implementation class AuthorListPageServlet ?*/ @WebServlet("/AuthorListPageServlet") public class AuthorListPageServlet extends HttpServlet { ?? ?private static final long serialVersionUID = 1L; ? ? ? ? ? ? /** ? ? ?* @see HttpServlet#HttpServlet() ? ? ?*/ ? ? public AuthorListPageServlet() { ? ? ? ? super(); ? ? ? ? // TODO Auto-generated constructor stub ? ? } ?? ?/** ?? ? * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response) ?? ? */ ?? ?protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException { ?? ??? ?// TODO Auto-generated method stub ?? ??? ?int pageSize = 2; ?? ??? ?AuthorDao ad = new AuthorDao(); ?? ??? ?//总记录数 ?? ??? ?int record = ad.queryUserListCount(); ?? ??? ?//接收页面传入的页码 ?? ??? ?String strPage = request.getParameter("currPage"); ?? ??? ?int currPage = 1;//默认第一页 ?? ??? ?if(strPage != null) { ?? ??? ??? ?currPage = Integer.parseInt(strPage); ?? ? ?? ??? ?} ?? ??? ? ?? ??? ?PageBean<Author> pb = new PageBean<Author>(currPage,pageSize,record); ?? ??? ?//查询某一页的结果集 ?? ??? ?List<Author> list = ad.queryUserListPage(pb.getPageIndex(), pageSize); ?? ??? ?pb.setList(list); ?? ??? ?request.setAttribute("pageBean", pb); ?? ??? ?request.getRequestDispatcher("userlistpage.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); ?? ?} }
(5)工具类:PageBean.java。作用是:获取结果集。
package com.util; import java.util.List; public class PageBean<T>{ ?? ?private int currentPage;//当前页码 ?? ?private int pageIndex;//数据起始索引 ?? ?private int pageSize;//每页条数 ?? ? ?? ? ?? ?private int record;//总记录数 ?? ?private int totalPage;//总页数 ?? ? ?? ?private List<T>list;//每页显示的结果集 ?? ?/** ?? ? * 构造方法初始化pageIndex和totalPage ?? ? * @param currentPage ?? ? * @param pageIndex ?? ? * @param pageSize ?? ? */ ?? ?public PageBean(int currentPage,int pageSize,int record) { ?? ??? ? ?? ??? ?this.currentPage = currentPage; ?? ??? ?this.pageSize = pageSize; ?? ??? ?this.record = record; ?? ??? ? ?? ??? ?//总页数 ?? ??? ?if(record % pageSize == 0) { ?? ??? ??? ?//整除,没有多余的页 ?? ??? ??? ?this.totalPage = record / pageSize; ?? ??? ??? ? ?? ??? ?} ?? ??? ?else { ?? ??? ??? ?//有多余的数据,在增加一页 ?? ??? ??? ?this.totalPage = record / pageSize + 1; ?? ??? ?} ?? ??? ? ?? ??? ?//计算数据起始索引pageIndex ?? ??? ?if(currentPage < 1) { ?? ??? ??? ?this.currentPage = 1; ?? ??? ?} ?? ??? ?else if(currentPage > this.totalPage) { ?? ??? ??? ?this.currentPage = this.totalPage; ?? ??? ?} ?? ??? ?this.pageIndex = (this.currentPage -1)*this.pageSize; ?? ?} ?? ? ?? ?public int getCurrentPage() { ?? ??? ?return currentPage; ?? ?} ?? ?public void setCurrentPage(int currentPage) { ?? ??? ?this.currentPage = currentPage; ?? ?} ?? ?public int getPageIndex() { ?? ??? ?return pageIndex; ?? ?} ?? ?public void setPageIndex(int pageIndex) { ?? ??? ?this.pageIndex = pageIndex; ?? ?} ?? ?public int getPageSize() { ?? ??? ?return pageSize; ?? ?} ?? ?public void setPageSize(int pageSize) { ?? ??? ?this.pageSize = pageSize; ?? ?} ?? ?public int getRecord() { ?? ??? ?return record; ?? ?} ?? ?public void setRecord(int record) { ?? ??? ?this.record = record; ?? ?} ?? ?public int getTotalPage() { ?? ??? ?return totalPage; ?? ?} ?? ?public void setTotalPage(int totalPage) { ?? ??? ?this.totalPage = totalPage; ?? ?} ?? ?public List<T> getList() { ?? ??? ?return list; ?? ?} ?? ?public void setList(List<T> list) { ?? ??? ?this.list = list; ?? ?} ?? ? }
三、运行结果
(1)首页:
(2)中间页:
(3)尾页:
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持脚本之家。
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