這篇文章主要介紹了jsp+servlet+javabean實現數據分頁方法,以完整實例形式詳細講述了jsp結合servlet與javabean操作PostgreSQL數據庫實現分頁的具體步驟,具有一定參考借鑒價值,需要的朋友可以參考下
本文實例講述了jsp+servlet+javabean實現數據分頁方法。分享給大家供大家參考,具體如下:
這里秉著且行且記的心態,記錄下學習過程,學得快忘得快,生怕遺忘,以備日后使用。
用到的部分代碼是自己在網上查找,并自己修改,加上自己的理解。也不知道算不算原創,只做自己學習記錄。
使用相關:PostgreSQL數據庫、dom4j、JSP、Servlet
一、首先是工程格局,來個全局視圖方便讀者與自己查看與使用
思路為:
以config.xml文件記錄配置信息,以方便數據庫更改,方便移植與重用。
DOM4JUtil.java用于解析xml屬性文件以獲得需要數據
PostgreSQL_Util.java分裝數據連接與數據庫操作
PageProperties.java為表格分頁屬性javaBean
PageProperties.java封裝分頁操作
Page.java為分頁主要操作
tablePage.jsp為效果顯示界面
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連接postgreSQL數據庫
分頁效果如下:能通過點擊上頁下頁實現翻頁,輸入指定頁面跳轉(超出范圍跳轉到第1或最后頁)。具體實現請參見詳細代碼,我都貼上來了。小菜鳥一名,處于正在學習階段,有大神能指點下當然更好,希望不吝賜教!
二、具體代碼實現
1、config.xml數據庫連接信息屬性文件
- <?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屬性文件
- * @author JohsonMuler
- *
- */
- public class DOM4JUtil {
- private static Element root=null;
- static{//靜態代碼塊
- //創建解析對象
- SAXReader sr=new SAXReader();
- //獲取當前工程路徑
- // String url=System.getProperty("user.dir");
- String url=DOM4JUtil.class.getResource("").getPath();
- // System.out.println(url);
- try {
- //通過文件路徑獲取配置文件信息
- Document doc=sr.read(url+"config.xml");
- //獲取根節點
- root=doc.getRootElement();
- } catch (DocumentException e) {
- e.printStackTrace();
- }
- }
- public static String getPostgresData(String str){
- //以根節點為基礎,獲取配置文件數據
- 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("未找到指定類:"+e.getMessage());
- } catch (SQLException e) {
- System.out.println("獲取連接異常:"+e.getMessage());
- }
- }
- /**
- * 數據查詢方法(Statement)
- * @param sql
- * @return
- * @throws SQLException
- */
- public ResultSet executeQuery(String sql) throws SQLException{
- Statement s=c.createStatement();
- rs=s.executeQuery(sql);
- return rs;
- }
- /**
- * 重載方法(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;
- }
- /**
- * 數據更新方法(添加,刪除,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;
- }
- /**
- * 重載方法(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;
- }
- /**
- * 單獨的獲取連接
- * @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;//當前頁號
- private int totalPages;//總頁數
- private int totalRecords;//總數據條數
- private ResultSet rs;//動態結果集
- 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;//當前頁號
- private int totalPages;//總頁數
- private int totalRecords;//總數據條數
- private ResultSet rs;//動態結果集
- 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這是主要處理類,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();
- /**
- * 通過TablePage設置分頁屬性
- *
- */
- TablePage tb=new TablePage();
- //獲取當前表格顯示的頁碼
- int currentPage=tb.currentPage(tb.getStrPage(request, "page"));
- System.out.println(currentPage);
- //設置每頁顯示數據條數
- tb.setPageRecord(10);//設置每頁顯示10條數據
- /**
- * 通過xxSQL_Util設置JDBC連接及數據處理
- */
- PostgreSQL_Util postgres=new PostgreSQL_Util();
- try {
- ResultSet rs_count=postgres.executeQuery("select count(*) as c from student");
- rs_count.next();
- //獲得總的數據條數
- int totalRecords=rs_count.getInt("c");
- //根據數據表的總數據條數獲取頁面顯示表格的總頁數
- int totalPages=tb.getTotalPages(totalRecords);
- if(currentPage>totalPages){
- currentPage=totalPages;//保證最后一頁不超出范圍
- }
- //根據數據庫表信息和當前頁面信息獲得動態結果集
- ResultSet rs=tb.getPageResultSet(postgres.executeQuery("select * from student"), currentPage);
- /**
- * 將數據加入javaBean
- */
- PageProperties pp=new PageProperties(currentPage, totalPages, totalRecords, rs);
- /**
- * 將javaBean轉發至前端
- */
- 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前臺顯示效果
- <%@ 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>簡單數據分頁</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>性別</td>
- <td>年齡</td>
- <td>分數</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() %>頁</span>
- <span>共<%=pp.getTotalRecords() %>條數據</span>
- <span>本頁<%=i-1 %>條</span>
- <span>第<%=pp.getCurrentPage() %>頁</span>
- <p align="center">
- <%
- if ( pp.getCurrentPage() > 1 )
- {
- %><a href="<%=path %>/page?page=<%=pp.getCurrentPage() - 1%>"><<上一頁</a>
- <%
- }
- %>
- <%
- if ( pp.getCurrentPage() < pp.getTotalPages() )
- {
- %><a href="<%=path %>/page?page=<%=pp.getCurrentPage() + 1%>">下一頁>></a>
- <%
- }
- %>
- <input type="text" name="input_text" id="input_text" size="1" />
- <input type="button" name="skip" id="skip" value="跳轉" 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,感覺后臺代碼實在是繁瑣,但這是考慮到程序健壯性與可移植性,方便代碼重用。以后要用,根據自己的需要在屬性文件(config.xml)中配置相關JDBC驅動,在jsp頁面通過request獲得后臺Servlet(Page.jsp)的轉發結果("result"),結合頁面屬性(PageProperties.java類)即可實現效果。
當然,這也是因為個人學習,傾向于多用點東西。
希望本文所述對大家jsp程序設計有所幫助。
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