jsp+servlet+javabean實現數據分頁方法完整實例

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：

這裡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，以備日後使用。
用到的部分代碼是自己在網上查找，並自己修改，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用於解析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用於xml文件解析
postgresql-9.3-1101.jdbc4.jar用於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或最後頁)。具體實現請參見詳細代碼，我都貼上來了。小菜鳥一名，處於正在學習階段，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;
/** 
 * 用於解析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;//保證最後一頁不超出范圍
   }
   //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前台顯示效果

<%@ 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，感覺後台代碼實在是繁瑣，但這是考慮到程序健壯性與可移植性，方便代碼重用。以後要用，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獲得後台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，傾向於多用點東西。

希望本文所述對大家jsp程序設計有所幫助。