今天寫了個jsp的分頁程序，以前在做jsp項目的時候，分頁采用的是“首頁，尾頁，上一頁，下一頁”的形式，雖然分頁沒有問題，但總感覺不夠友好，現在很多論壇都采用這種模式，即根據用戶請求的頁面，列出請求頁面和該頁面的前幾頁和后幾頁，看上去比較舒服，今天就模仿“編程中國論壇”的分頁風格練了練，后臺查詢數據庫的分頁代碼與之前做過的基本沒有變化，主要是在jsp頁面上多了些判斷，效果實現了，至于效率我就不好說了，如果哪位看過下面代碼的朋友有什么好方法，還望大家能夠一起交流，共同進步。
該程序采用了MVC設計模式，代碼中的ServletX為總控制器，根據model值將請求轉至相應模塊，后臺數據庫為Oracle，由于emp表中數據只有15條，所以我每頁只顯示一條記錄，效果如圖：
1，用戶登錄，若登錄成功轉到main.jsp頁面，以下為用戶控制器代碼：
package controls;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import entitys.User;
import routines.Translation;
import operater.*;
import java.util.*;
public class UserServlet extends HttpServlet 
{
/** *//**
* Constructor of the object.
*/
public UserServlet() {
super();
}
/** *//**
* Destruction of the servlet. <br>
*/
public void destroy() {
super.destroy(); // Just puts "destroy" string in log
// Put your code here
}
/** *//**
* The doGet method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to get.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String event = request.getParameter("event");
if(event.equals("login")){
String userName = Translation.transCode(request.getParameter("userName"));
String password = Translation.transCode(request.getParameter("password"));
User user = new User();
user.setUserName(userName);
user.setPassword(password);
OperUser obj = new OperUser();
if(obj.isExist(user)){
this.mySet(request,"1");
request.getRequestDispatcher("main.jsp").forward(request, response);
return;
}else{
System.out.println("失敗");
}
}
}
private void mySet(HttpServletRequest request,Object pageNo){
OperEmp emp = new OperEmp();
//向請求中存儲關于分頁的信息
ArrayList aryInfo = emp.getEmp(pageNo);
request.setAttribute("data", aryInfo.get(0));
request.setAttribute("pageNo", aryInfo.get(1));
request.setAttribute("pageCount", aryInfo.get(2));
request.setAttribute("rowsCount", aryInfo.get(3));
ArrayList aryNumber = new ArrayList();
for(int i=1;i<=10;i++){
aryNumber.add(new Integer(i));
}
request.setAttribute("number", aryNumber);
ArrayList aryNumberR = new ArrayList();
for(int i=9;i>=0;i--){
aryNumberR.add(new Integer(i));
}
request.setAttribute("numberR", aryNumberR);
//向請求中存儲關于職位的信息
ArrayList aryJob = emp.getJob();
request.setAttribute("job", aryJob);
//向請求中存儲關于部門編號的信息
OperDept dept = new OperDept();
ArrayList aryDeptno = dept.getDeptno();
request.setAttribute("deptno", aryDeptno);
}
/** *//**
* The doPost method of the servlet. <br>
*
* This method is called when a form has its tag value method equals to post.
*
* @param request the request send by the client to the server
* @param response the response send by the server to the client
* @throws ServletException if an error occurred
* @throws IOException if an error occurred
*/
public void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
/** *//**
* Initialization of the servlet. <br>
*
* @throws ServletException if an error occure
*/
public void init() throws ServletException {
// Put your code here
}
}
2，main.jsp頁面，即顯示分頁的頁面的代碼：
<%@page contentType="text/html" pageEncoding="GBK"%>
<%@ taglib prefix="c" uri="http://java.sun.com/jstl/core_rt"%>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<title>職員信息</title>
<script type="text/javascript">
function go(){
var page = document.frmMain.pageNo.value;
window.location.href = 'ServletX?model=emp&event=partitionPage&pageNo=' + page;
return;
}
</script>
</head>
<body>
<form name="frmMain" action="ServletX" method="get">
<table border="1" align="center">
<caption>
職員信息表
</caption>
<tr>
<th onclick="selectAll(this)" style="cursor:hand">全選</th>
<th>職員編號</th>
<th>職員姓名</th>
<th>職位</th>
<th>直接上司</th>
<th>入職時間</th>
<th>薪金</th>
<th>獎金</th>
<th>部門編號</th>
<th>操作</th>
</tr>
<c:forEach var="obj" items="${requestScope.data}">
<tr>
<td align="center"><input type="checkbox" name="${obj.empNo}"/></td>
<td>${obj.empNo}</td>
<td>${obj.ename}</td>
<td>${obj.job}</td>
<td>${obj.mgr}</td>
<td>${obj.hireDate}</td>
<td>${obj.sal}</td>
<td>${obj.comm}</td>
<td>${obj.deptno}</td>
<td><input type="button" value="編輯"/></td>
</tr>
</c:forEach>
<tr>
<td colspan="10" align="left">
總記錄數:${requestScope.rowsCount}
<c:choose>
<c:when test="${requestScope.pageCount <= 10}">
<c:if test="${requestScope.pageNo != 1}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo - 1}"><<</a>
</c:if>
<c:forEach var="num" begin="0" end="${requestScope.pageCount - 1}" items="${requestScope.number}">
<c:choose>
<c:when test="${requestScope.pageNo != num}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${num}">${num}</a>
</c:when>
<c:otherwise>
<font color="red">${requestScope.pageNo}</font>
</c:otherwise>
</c:choose>
</c:forEach>
<c:if test="${requestScope.pageNo != requestScope.pageCount}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo + 1}">>></a>
</c:if>
</c:when>
<c:otherwise>
<c:choose>
<c:when test="${requestScope.pageNo > 3 && requestScope.pageNo < requestScope.pageCount - 7}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=1">1</a>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo - 1}"><<</a>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo - 2}">${requestScope.pageNo - 2}</a>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo - 1}">${requestScope.pageNo - 1}</a>
<font color="red">${requestScope.pageNo}</font>
<c:forEach var="num" items="${requestScope.number}" begin="0" end="6">
<c:if test="${requestScope.pageNo + num <= pageCount}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo + num}">${requestScope.pageNo + num}</a>
</c:if>
</c:forEach>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo + 1}">>></a>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageCount}">..${requestScope.pageCount}</a>
</c:when>
<c:when test="${requestScope.pageNo > 3 && requestScope.pageNo >= requestScope.pageCount -7 && requestScope.pageNo != requestScope.pageCount}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=1">1</a>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo - 1}"><<</a>
<c:forEach var="numR" items="${requestScope.numberR}" begin="0">
<c:choose>
<c:when test="${requestScope.pageCount - numR != requestScope.pageNo}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageCount - numR}">${requestScope.pageCount - numR}</a>
</c:when>
<c:otherwise>
<font color="red">${requestScope.pageNo}</font>
</c:otherwise>
</c:choose>
</c:forEach>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo + 1}">>></a>
</c:when>
<c:when test="${requestScope.pageNo <= 3 && requestScope.pageNo > 1}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo - 1}"><<</a>
<c:forEach var="num" items="${requestScope.number}">
<c:choose>
<c:when test="${requestScope.pageNo != num}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${num}">${num}</a>
</c:when>
<c:otherwise>
<font color="red">${requestScope.pageNo}</font>
</c:otherwise>
</c:choose>
</c:forEach>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo + 1}">>></a>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageCount}">..${requestScope.pageCount}</a>
</c:when>
<c:when test="${requestScope.pageNo == 1}">
<c:forEach var="num" items="${requestScope.number}">
<c:choose>
<c:when test="${requestScope.pageNo != num}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${num}">${num}</a>
</c:when>
<c:otherwise>
<font color="red">${requestScope.pageNo}</font>
</c:otherwise>
</c:choose>
</c:forEach>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo + 1}">>></a>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageCount}">..${requestScope.pageCount}</a>
</c:when>
<c:when test="${requestScope.pageNo == requestScope.pageCount}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=1">1</a>
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageNo - 1}"><<</a>
<c:forEach var="numR" items="${requestScope.numberR}" begin="0">
<c:choose>
<c:when test="${requestScope.pageCount - numR != requestScope.pageNo}">
<a href="ServletX?model=emp&event=partitionPage&pageNo=${requestScope.pageCount - numR}">${requestScope.pageCount - numR}</a>
</c:when>
<c:otherwise>
<font color="red">${requestScope.pageNo}</font>
</c:otherwise>
</c:choose>
</c:forEach>
</c:when>
</c:choose>
</c:otherwise>
</c:choose>
<input name="pageNo" type="text" size="3"/>
<input type="button" onclick="go()" value="GO"/>
</td>
</tr>
<tr>
<td colspan="10" align="center">
<input type="button" value="增加" onclick="addRow()"/>
<input type="submit" value="保存" onclick="saveRow()"/>
<input type="submit" value="刪除" onclick="deleteRow()"/>
</td>
</tr>
</table>
</form>
</body>
</html>
3，用戶點擊相應頁面鏈接或通過文本框請求頁面時，即emp表的控制器，方法類似于用戶登錄成功后的處理，代碼如下：
/**//*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package controls;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
import entitys.Emp;
import routines.Translation;
import operater.*;
import java.util.*;
/** *//**
*
* @author Administrator
*/
public class EmpServlet extends HttpServlet {
/** *//**
* Processes requests for both HTTP <code>GET</code> and <code>POST</code> methods.
* @param request servlet request
* @param response servlet response
*/
protected void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
response.setContentType("text/html;charset=UTF-8");
PrintWriter out = response.getWriter();
try {
/**//* TODO output your page here
out.println("<html>");
out.println("<head>");
out.println("<title>Servlet EmpServlet</title>");
out.println("</head>");
out.println("<body>");
out.println("<h1>Servlet EmpServlet at " + request.getContextPath () + "</h1>");
out.println("</body>");
out.println("</html>");
*/
} finally {
out.close();
}
}
/** *//**
* Handles the HTTP <code>GET</code> method.
* @param request servlet request
* @param response servlet response
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String event = request.getParameter("event");
if(event.equals("partitionPage")){
String pageNo = request.getParameter("pageNo");
this.mySet(request, pageNo);
request.getRequestDispatcher("main.jsp").forward(request, response);
return;
}
}
private void mySet(HttpServletRequest request, Object pageNo) {
OperEmp emp = new OperEmp();
//向請求中存儲關于分頁的信息
ArrayList aryInfo = emp.getEmp(pageNo);
request.setAttribute("data", aryInfo.get(0));
request.setAttribute("pageNo", aryInfo.get(1));
request.setAttribute("pageCount", aryInfo.get(2));
request.setAttribute("rowsCount", aryInfo.get(3));
ArrayList aryNumber = new ArrayList();
for (int i = 1; i <= 10; i++) {
aryNumber.add(new Integer(i));
}
request.setAttribute("number", aryNumber);
ArrayList aryNumberR = new ArrayList();
for (int i = 9; i >=0; i--) {
aryNumberR.add(new Integer(i));
}
request.setAttribute("numberR", aryNumberR);
//向請求中存儲關于職位的信息
ArrayList aryJob = emp.getJob();
request.setAttribute("job", aryJob);
//向請求中存儲關于部門編號的信息
OperDept dept = new OperDept();
ArrayList aryDeptno = dept.getDeptno();
request.setAttribute("deptno", aryDeptno);
}
/** *//**
* Handles the HTTP <code>POST</code> method.
* @param request servlet request
* @param response servlet response
*/
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
this.doGet(request, response);
}
/** *//**
* Returns a short description of the servlet.
*/
public String getServletInfo() {
return "Short description";
}
}
4，該類為分頁查詢代碼，用戶可隨需要改變頁面顯示的記錄行數，代碼如下：
package operater;
import java.sql.*;
import entitys.Emp;
import db.DataBase;
import java.util.*;
/** *//**
*該類用于完成對用戶信息表操作的業務邏輯
* @author 非凡DZ
*/
public class OperEmp {
private Connection con = null;
private PreparedStatement pstn = null;
private ResultSet rs = null;
private int pageCount = 0;//記錄總頁數
private int pageNo = 0;//記錄要前往的頁數
private int pageRows = 6;//記錄每頁的行數
private int rowsCount = 0;//記錄總行數
private int i = 0;//用于控制循環次數
/** *//**
* 根據請求的頁數得到相應的數據
* @param page 請求的頁碼
* @return 請求頁碼中的信息,請求頁碼及總頁數
*/
public ArrayList getEmp(Object page){
if(page == null){
pageNo = 1;
}else{
pageNo = Integer.parseInt(page.toString());
}
if(pageNo < 1){
pageNo = 1;
}
DataBase db = new DataBase();
con = db.getConnection();
String sql = "select * from emp";
ArrayList aryInfo = new ArrayList();
ArrayList aryEmp = new ArrayList();//記錄所有
try {
pstn = con.prepareStatement(sql, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
rs = pstn.executeQuery();
rs.last();
rowsCount = rs.getRow();
pageCount = (rowsCount + pageRows - 1) / pageRows;
if(pageNo > pageCount){
pageNo = pageCount;
}
if(pageCount > 0){
rs.absolute((pageNo - 1) * pageRows + 1);
}
while(i < pageRows && !rs.isAfterLast()){
Emp emp = new Emp();
emp.setEmpNo(rs.getInt(1));
emp.setEname(rs.getString(2));
emp.setJob(rs.getString(3));
emp.setMgr(rs.getInt(4));
emp.setHireDate(rs.getString(5));
emp.setSal(rs.getFloat(6));
emp.setDeptno(rs.getInt(7));
aryEmp.add(emp);
rs.next();
i++;
}
} catch (Exception e) {
System.out.println("分頁異常"+e.getMessage());
}
aryInfo.add(aryEmp);
aryInfo.add(new Integer(pageNo));//當前頁數
aryInfo.add(new Integer(pageCount));//總頁數
aryInfo.add(new Integer(rowsCount));//總行數
return aryInfo;
}
/** *//**
* 得到所有職位
* @return
*/
public ArrayList getJob(){
DataBase db = new DataBase();
con = db.getConnection();
boolean flag = false;
String sql = "select job from emp";
ArrayList aryJob = new ArrayList();
try{
pstn = con.prepareStatement(sql, ResultSet.TYPE_SCROLL_INSENSITIVE, ResultSet.CONCUR_READ_ONLY);
rs = pstn.executeQuery();
while (rs.next()) {
flag = false;
for (int i = 0; i < aryJob.size(); i++) {
String job = (String) aryJob.get(i);
if (job.equals(rs.getString(1))) {
flag = true;
break;
}
}
if (!flag) {
aryJob.add(rs.getString(1));
}
}
}catch(Exception e){
System.out.println("職位查詢異常"+e.getMessage());
}
return aryJob;
}
}
以上程序中有一些代碼是用于編輯數據用的，如用于存儲職位，部門編號的集合等