JSP实现数据库分页查询
1 数据库建表
在MySQL数据库中创建名为javaee的数据库，数据库中建一个名为news_inf的表，表有两列一列为news_id、一列为news_title
数据库javaee.sql文件如下
# --------------------------------------------------------
# Host: localhost
# Server version: 5.5.58
# Server OS: Win32
# HeidiSQL version: 6.0.0.3832
# Date/time: 2018-07-04 14:17:59
# --------------------------------------------------------
/*!40101 SET @OLD_CHARACTER_SET_CLIENT=@@CHARACTER_SET_CLIENT */;
/*!40101 SET NAMES utf8 */;
/*!40014 SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0 */;
/*!40101 SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='NO_AUTO_VALUE_ON_ZERO' */;
# Dumping database structure for javaee
CREATE DATABASE IF NOT EXISTS `javaee` /*!40100 DEFAULT CHARACTER SET utf8 */;
USE `javaee`;
# Dumping structure for table javaee.news_inf
CREATE TABLE IF NOT EXISTS `news_inf` (
`news_id` int(11) NOT NULL AUTO_INCREMENT,
`news_title` varchar(255) DEFAULT NULL,
PRIMARY KEY (`news_id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8;
# Dumping data for table javaee.news_inf: ~10 rows (approximately)
/*!40000 ALTER TABLE `news_inf` DISABLE KEYS */;
INSERT INTO `news_inf` (`news_id`, `news_title`) VALUES
(1, 'first'),
(2, 'second'),
(3, 'third'),
(4, 'fouth'),
(5, 'fifth'),
(6, 'sixth'),
(7, 'seven'),
(8, 'eight'),
(9, 'nine'),
(10, 'tenth');
/*!40000 ALTER TABLE `news_inf` ENABLE KEYS */;
/*!40101 SET SQL_MODE=@OLD_SQL_MODE */;
/*!40014 SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS */;
/*!40101 SET CHARACTER_SET_CLIENT=@OLD_CHARACTER_SET_CLIENT */;可以使用HeidiSQL将sql文件导入数据库。
2 新建javaWeb项目
在eclipse中新建javaWeb项目，并命名为SpiltPageDB
1.1建立访问数据库的bean文件
在java Resources目录下的src包下新建一个Package命名为bean，在bean包下新建java类命名为SpiltPage.java，类文件内如如下
package bean;
import java.sql.Connection;
import java.sql.ResultSet;
import java.sql.ResultSetMetaData;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.Vector;
public class SpiltPage {
//定义数据库连接对象和结果集对象
private Connection con = null;
private Statement stmt = null;
private ResultSet rs = null;
private ResultSetMetaData rsmd = null;
//SQL查询语句
private String sqlStr;
//总记录数目
private int rowCount = 0;
//所分的逻辑页数
private int pageCount = 0;
//每页显示的记录数目
private int pageSize = 0;
//设置参数值
public void setCon(Connection con) {
this.con = con;
if(null==this.con) {
System.out.println("Failure to get a connection");
}else {
System.out.println("Success to get a connection");
}
}
//初始化数据库表中的信息
public void initialize(String sqlStr,int pageSize,int ipage) {
int irows = pageSize*(ipage-1);
this.sqlStr = sqlStr;
this.pageSize = pageSize;
try {
stmt = this.con.createStatement();
rs = stmt.executeQuery(this.sqlStr);
if(null != rs) {
rs.last();
this.rowCount = rs.getRow();
rs.first();
this.pageCount = (this.rowCount-1)/this.pageSize+1;
}
this.sqlStr = sqlStr+" limit "+irows+","+pageSize;
stmt = this.con.createStatement();
rs = stmt.executeQuery(this.sqlStr);
rsmd = rs.getMetaData();
}catch(SQLException e) {
System.out.println("zcn数据库异常："+e.toString());
}
}
//将显示结果存到Vector
public Vector getPage() {
Vector vData = new Vector();
try {
if(null != rs) {
while(rs.next()) {
String[] sData = new String[2];
for(int j=0;j1);
}
vData.addElement(sData);
}
}
rs.close();
stmt.close();
}catch(SQLException e) {
System.out.println("zcn数据库异常："+e.toString());
}
return vData;
}
//获得页面总数
public int getPageCount() {
return this.pageCount;
}
//获取数据表
public int getRowCount() {
return this.rowCount;
}
} 1.2建立显示用的jsp页面
在webContent目录下新建words_list_javabean.jsp页面，页面内容如下
注：需要把数据库用户名和密码改成自己电脑数据库的用户名和密码
<%@ page language="java" contentType="text/html; charset=utf-8"
pageEncoding="utf-8"%>
<%@page import="java.sql.*" %>
<%@page import="java.io.*" %>
<%@page import="java.util.*" %>
<%@page import="bean.*"%>
<jsp:useBean id="pages" scope="page" class="bean.SpiltPage"/>
<%!
//每页显示的记录数
int pageSize = 3;
String sqlStr="";
//当前页
int showPage=1;
//数据库用户名
String userName="root";
//数据库密码
String userPassword="123";
//数据库的URL,包括连接数据库所使用的编码格式
String url="jdbc:mysql://localhost:3306/javaee";
//定义连接对象
Connection dbcon;
%>
<%
try{
//加载驱动程序
Class.forName("com.mysql.jdbc.Driver");
//获得数据库的连接对象
dbcon = DriverManager.getConnection(url,userName,userPassword);
}catch(SQLException e){
//打印出异常信息
System.out.println(e.toString());
}
//给pages中参数con赋值
pages.setCon(dbcon);
sqlStr="select * from news_inf order by news_id";
//查询数据表，获得查询结果
String strPage = null;
//获取跳转到的目的的页面
strPage = request.getParameter("showPage");
if(null == strPage){
showPage=1;
}else{
try{
showPage=Integer.parseInt(strPage);
}catch(NumberFormatException e){
showPage = 1;
}
if(showPage<1){
showPage=1;
}
}
pages.initialize(sqlStr, pageSize, showPage);
//获取要显示的数据集合
Vector vData = pages.getPage();
%>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>分页显示title>
head>
<body bgcolor="#FFFFFF" text="#000000">
<h1 align=center>留言簿h1>
<div align=center>
<table border="1" cellspacing="0" cellpadding="0" width="80%">
<tr>
<th width="20%">编号th>
<th width="50%">标题th>
tr>
<%
for(int i=0;iString [] sData=(String[])vData.get(i);
%>
<tr>
<td><%=sData[0]%>td>
<td align=left><%=sData[1]%>td>
tr>
<%}%>
table>
<form action="words_list_javabean.jsp" mehod="get" target="_self">
共<font color=red><%=pages.getRowCount()%>font>条
<%=pageSize%>条/页
第<font color=red><%=showPage%>font>页/共
<font color=red><%=pages.getPageCount()%>font>页
<a href="words_list_javabean.jsp?showPage=1" target="_self">[首页]a>
<%
//判断“上一页”链接是否要显示
if(showPage>1){
%>
<a href="words_list_javabean.jsp?showPage=<%=showPage-1%>"target="_self">[上一页]a>
<%
}else{
%>
[上一页]
<%
}
//判断下一页链接是否显示
if(showPage3 运行显示
至此就可以将web项目跑到Tomcat服务器上，并在浏览器上访问，访问的网址为：
http://localhost:8080/SpiltPageDB/words_list_javabean.jsp注：SpiltPageDB为你建立的web项目的名字