这篇文章主要介绍了jsp+servlet+javabean实现数据分页方法,以完整实例形式详细讲述了jsp结合servlet与javabean操作PostgreSQL数据库实现分页的具体步骤,具有一定参考借鉴价值,需要的朋友可以参考下
本文实例讲述了jsp+servlet+javabean实现数据分页方法。分享给大家供大家参考,具体如下:
这里秉着且行且记的心态,记录下学习过程,学得快忘得快,生怕遗忘,以备日后使用。
用到的部分代码是自己在网上查找,并自己修改,加上自己的理解。也不知道算不算原创,只做自己学习记录。
使用相关:PostgreSQL数据库、dom4j、JSP、Servlet
一、首先是工程格局,来个全局视图方便读者与自己查看与使用
思路为:
以config.xml文件记录配置信息,以方便数据库更改,方便移植与重用。
DOM4JUtil.java用于解析xml属性文件以获得需要数据
PostgreSQL_Util.java分装数据连接与数据库操作
PageProperties.java为表格分页属性javaBean
PageProperties.java封装分页操作
Page.java为分页主要操作
tablePage.jsp为效果显示界面
用到的第三方jar包:
dom4j-1.6.1.jar用于xml文件解析
postgresql-9.3-1101.jdbc4.jar用于JDBC连接postgreSQL数据库
分页效果如下:能通过点击上页下页实现翻页,输入指定页面跳转(超出范围跳转到第1或最后页)。具体实现请参见详细代码,我都贴上来了。小菜鸟一名,处于正在学习阶段,有大神能指点下当然更好,希望不吝赐教!
二、具体代码实现
1、config.xml数据库连接信息属性文件
- <?xml version="1.0" encoding="utf-8"?>
- <!DOCTYPE postgres[
- <!ELEMENT postgres (driver,url,username,pwd)>
- <!ELEMENT driver (#PCDATA)>
- <!ELEMENT url (#PCDATA)>
- <!ELEMENT username (#PCDATA)>
- <!ELEMENT pwd (#PCDATA)>
- ]>
- <postgres>
- <driver>org.postgresql.Driver</driver>
- <url>jdbc:postgresql://localhost:5432/java</url>
- <username>admin</username>
- <pwd>k42jc</pwd>
- </postgres>
2、DOM4JUtil.java
- package util;
- import org.dom4j.Document;
- import org.dom4j.DocumentException;
- import org.dom4j.Element;
- import org.dom4j.io.SAXReader;
- /**
- * 用于解析xml属性文件
- * @author JohsonMuler
- *
- */
- public class DOM4JUtil {
- private static Element root=null;
- static{//静态代码块
- //创建解析对象
- SAXReader sr=new SAXReader();
- //获取当前工程路径
- // String url=System.getProperty("user.dir");
- String url=DOM4JUtil.class.getResource("").getPath();
- // System.out.println(url);
- try {
- //通过文件路径获取配置文件信息
- Document doc=sr.read(url+"config.xml");
- //获取根节点
- root=doc.getRootElement();
- } catch (DocumentException e) {
- e.printStackTrace();
- }
- }
- public static String getPostgresData(String str){
- //以根节点为基础,获取配置文件数据
- Element e=root.element(str);
- String data=e.getText();
- return data;
- }
- public static void main(String[] args) {
- // String url=DOM4JUtil.class.getResource("..").getPath();
- // System.out.println(System.getProperty("user.dir"));
- // System.out.println(url);
- String driver=getPostgresData("driver");
- String url=getPostgresData("url");
- System.out.println(driver);
- System.out.println(url);
- }
- }
3、PostgreSQL_Util.java
- package util;
- import java.sql.PreparedStatement;
- import java.sql.Statement;
- import java.sql.Connection;
- import java.sql.DriverManager;
- import java.sql.ResultSet;
- import java.sql.SQLException;
- import java.util.List;
- public class PostgreSQL_Util {
- private static DOM4JUtil dom=new DOM4JUtil();
- private static Connection c=null;
- private static ResultSet rs=null;
- private static String driver=dom.getPostgresData("driver");
- private static String url=dom.getPostgresData("url");
- private static String username=dom.getPostgresData("username");
- private static String pwd=dom.getPostgresData("pwd");
- public PostgreSQL_Util(){
- try {
- Class.forName(driver);
- c=DriverManager.getConnection(url);
- } catch (ClassNotFoundException e) {
- System.out.println("未找到指定类:"+e.getMessage());
- } catch (SQLException e) {
- System.out.println("获取连接异常:"+e.getMessage());
- }
- }
- /**
- * 数据查询方法(Statement)
- * @param sql
- * @return
- * @throws SQLException
- */
- public ResultSet executeQuery(String sql) throws SQLException{
- Statement s=c.createStatement();
- rs=s.executeQuery(sql);
- return rs;
- }
- /**
- * 重载方法(PreparedStatement)
- * @param sql
- * @param list
- * @return
- * @throws SQLException
- */
- public ResultSet executeQuery(String sql,List<Object> list) throws SQLException{
- PreparedStatement ps=c.prepareStatement(sql);
- for(int i=0;i<list.size();i++){
- System.out.println(list.get(i));
- System.out.println(i+1);
- ps.setObject(i+1, list.get(i));
- }
- rs=ps.executeQuery();
- c.close();
- return rs;
- }
- /**
- * 数据更新方法(添加,删除,更改)(Statement)
- * @param sql
- * @throws SQLException
- */
- public int executeUpdate(String sql) throws SQLException{
- Statement s=c.createStatement();
- int i=s.executeUpdate(sql);
- c.close();
- return i;
- }
- /**
- * 重载方法(PreparedStatement)
- * @param sql
- * @param list
- * @throws SQLException
- */
- public int executeUpdate(String sql,List<Object> list) throws SQLException{
- PreparedStatement ps=c.prepareStatement(sql);
- for(int i=0;i<list.size();i++){
- ps.setObject(i+1, list.get(i));
- }
- int i=ps.executeUpdate();
- c.close();
- return i;
- }
- /**
- * 单独的获取连接
- * @return
- * @throws ClassNotFoundException
- * @throws SQLException
- */
- public static Connection getConnection() throws ClassNotFoundException, SQLException{
- Class.forName(driver);
- c=DriverManager.getConnection(url);
- return c;
- }
- }
4、PageProperties.java
- package bean;
- import java.sql.ResultSet;
- public class PageProperties {
- private int currentPage;//当前页号
- private int totalPages;//总页数
- private int totalRecords;//总数据条数
- private ResultSet rs;//动态结果集
- public PageProperties() {
- super();
- }
- public PageProperties(int currentPage, int totalPages, int totalRecords,
- ResultSet rs) {
- super();
- this.currentPage = currentPage;
- this.totalPages = totalPages;
- this.totalRecords = totalRecords;
- this.rs = rs;
- }
- public int getCurrentPage() {
- return currentPage;
- }
- public void setCurrentPage(int currentPage) {
- this.currentPage = currentPage;
- }
- public int getTotalPages() {
- return totalPages;
- }
- public void setTotalPages(int totalPages) {
- this.totalPages = totalPages;
- }
- public int getTotalRecords() {
- return totalRecords;
- }
- public void setTotalRecords(int totalRecords) {
- this.totalRecords = totalRecords;
- }
- public ResultSet getRs() {
- return rs;
- }
- public void setRs(ResultSet rs) {
- this.rs = rs;
- }
- }
5、TablePage.java
- package bean;
- import java.sql.ResultSet;
- public class PageProperties {
- private int currentPage;//当前页号
- private int totalPages;//总页数
- private int totalRecords;//总数据条数
- private ResultSet rs;//动态结果集
- public PageProperties() {
- super();
- }
- public PageProperties(int currentPage, int totalPages, int totalRecords,
- ResultSet rs) {
- super();
- this.currentPage = currentPage;
- this.totalPages = totalPages;
- this.totalRecords = totalRecords;
- this.rs = rs;
- }
- public int getCurrentPage() {
- return currentPage;
- }
- public void setCurrentPage(int currentPage) {
- this.currentPage = currentPage;
- }
- public int getTotalPages() {
- return totalPages;
- }
- public void setTotalPages(int totalPages) {
- this.totalPages = totalPages;
- }
- public int getTotalRecords() {
- return totalRecords;
- }
- public void setTotalRecords(int totalRecords) {
- this.totalRecords = totalRecords;
- }
- public ResultSet getRs() {
- return rs;
- }
- public void setRs(ResultSet rs) {
- this.rs = rs;
- }
- }
6、Page.java这是主要处理类,Servlet
- package servlet;
- import java.io.IOException;
- import java.io.PrintWriter;
- import java.sql.ResultSet;
- import java.sql.SQLException;
- import javax.servlet.ServletException;
- import javax.servlet.http.HttpServlet;
- import javax.servlet.http.HttpServletRequest;
- import javax.servlet.http.HttpServletResponse;
- import util.PostgreSQL_Util;
- import bean.PageProperties;
- import bean.TablePage;
- public class Page extends HttpServlet {
- public void service(HttpServletRequest request, HttpServletResponse response)
- throws ServletException, IOException {
- request.setCharacterEncoding("utf-8");
- response.setContentType("text/html;charset=utf-8");
- PrintWriter out = response.getWriter();
- /**
- * 通过TablePage设置分页属性
- *
- */
- TablePage tb=new TablePage();
- //获取当前表格显示的页码
- int currentPage=tb.currentPage(tb.getStrPage(request, "page"));
- System.out.println(currentPage);
- //设置每页显示数据条数
- tb.setPageRecord(10);//设置每页显示10条数据
- /**
- * 通过xxSQL_Util设置JDBC连接及数据处理
- */
- PostgreSQL_Util postgres=new PostgreSQL_Util();
- try {
- ResultSet rs_count=postgres.executeQuery("select count(*) as c from student");
- rs_count.next();
- //获得总的数据条数
- int totalRecords=rs_count.getInt("c");
- //根据数据表的总数据条数获取页面显示表格的总页数
- int totalPages=tb.getTotalPages(totalRecords);
- if(currentPage>totalPages){
- currentPage=totalPages;//保证最后一页不超出范围
- }
- //根据数据库表信息和当前页面信息获得动态结果集
- ResultSet rs=tb.getPageResultSet(postgres.executeQuery("select * from student"), currentPage);
- /**
- * 将数据加入javaBean
- */
- PageProperties pp=new PageProperties(currentPage, totalPages, totalRecords, rs);
- /**
- * 将javaBean转发至前端
- */
- request.setAttribute("result", pp);
- request.getRequestDispatcher("tablePage.jsp").forward(request, response);
- } catch (SQLException e) {
- System.out.println("Class Page:"+e.getMessage());
- // e.printStackTrace();
- }
- }
- }
7、tablePage.jsp前台显示效果
- <%@ page language="java" import="java.util.*" pageEncoding="utf-8"%>
- <%@page import="java.sql.ResultSet"%>
- <%@page import="bean.PageProperties"%>
- <%@taglib prefix="c" uri="http://java.sun.com/jsp/jstl/core"%>
- <%
- String path = request.getContextPath();
- String basePath = request.getScheme()+"://"+request.getServerName()+":"+request.getServerPort()+path+"/";
- %>
- <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
- <html>
- <head>
- <title>简单数据分页</title>
- <meta http-equiv="pragma" content="no-cache">
- <meta http-equiv="cache-control" content="no-cache">
- <meta http-equiv="expires" content="0">
- <meta http-equiv="keywords" content="keyword1,keyword2,keyword3">
- <meta http-equiv="description" content="This is my page">
- <!--
- <link rel="stylesheet" type="text/css" href="styles.css">
- -->
- </head>
- <body>
- <table>
- <tr>
- <td>姓名</td>
- <td>性别</td>
- <td>年龄</td>
- <td>分数</td>
- </tr>
- <%
- PageProperties pp=(PageProperties)request.getAttribute("result");
- ResultSet rs=pp.getRs();
- %>
- <%
- int i=1;
- while(rs.next()){
- %>
- <tr>
- <td><%=rs.getObject(1) %></td>
- <td><%=rs.getObject(2) %></td>
- <td><%=rs.getObject(3) %></td>
- <td><%=rs.getObject(4) %></td>
- </tr>
- <%
- i++;
- if(i>10)
- break;
- }
- %>
- <br/>
- <span><%=pp.getTotalPages() %>页</span>
- <span>共<%=pp.getTotalRecords() %>条数据</span>
- <span>本页<%=i-1 %>条</span>
- <span>第<%=pp.getCurrentPage() %>页</span>
- <p align="center">
- <%
- if ( pp.getCurrentPage() > 1 )
- {
- %><a href="<%=path %>/page?page=<%=pp.getCurrentPage() - 1%>"><<上一页</a>
- <%
- }
- %>
- <%
- if ( pp.getCurrentPage() < pp.getTotalPages() )
- {
- %><a href="<%=path %>/page?page=<%=pp.getCurrentPage() + 1%>">下一页>></a>
- <%
- }
- %>
- <input type="text" name="input_text" id="input_text" size="1" />
- <input type="button" name="skip" id="skip" value="跳转" onclick="skip();"/>
- <script>
- function skip(){
- var v=document.getElementById("input_text").value;
- location.href="page?page="+v;
- }
- </script>
- </p>
- </table>
- </body>
- </html>
初步看,感觉后台代码实在是繁琐,但这是考虑到程序健壮性与可移植性,方便代码重用。以后要用,根据自己的需要在属性文件(config.xml)中配置相关JDBC驱动,在jsp页面通过request获得后台Servlet(Page.jsp)的转发结果("result"),结合页面属性(PageProperties.java类)即可实现效果。
当然,这也是因为个人学习,倾向于多用点东西。
希望本文所述对大家jsp程序设计有所帮助。
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