java分页技术

java代码

定义实体类：

package cn.pdsu;/** * 类说明：学生信息封装 *  * @author 作者: LiuJunGuang * @version 创建时间：2011-11-9 下午02:30:50 */public class Student {private int id;private String name;private String sex;private String resume;public Student(int id, String name, String sex, String resume) {super();this.id = id;this.name = name;this.sex = sex;this.resume = resume;}public Student() {super();}public int getId() {return id;}public void setId(int id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public String getSex() {return sex;}public void setSex(String sex) {this.sex = sex;}public String getResume() {return resume;}public void setResume(String resume) {this.resume = resume;}@Overridepublic String toString() {return "Student [id=" + id + ", name=" + name + ", sex=" + sex+ ", resume=" + resume + "]";}}

package cn.pdsu;import java.util.LinkedList;import java.util.List;/** * 类说明：数据的封装 *  * @author 作者: LiuJunGuang * @version 创建时间：2011-11-9 下午02:28:27 */public class DataSourceDAO {private static List<Student> list = new LinkedList<Student>();static {for (int i = 0; i < 20; i++) {list.add(new Student(i, "张山" + i, "男", "学生" + i));}}/** * 模拟数据库中分页查询 *  * @param startIndex *            要查询的开始索引 * @param count *            查询的总记录数 * @return 查询出的学生记录 */public List<Student> findStudent(int startIndex, int count) {int num = count + startIndex;if (num > list.size())num = list.size();return list.subList(startIndex, num);}/** * 模拟数据库中查询总记录数 *  * @return 总的记录数 */public int count() {return list.size();}}

package cn.pdsu;import java.io.IOException;import java.util.List;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;/** * 类说明：分页控制器 *  * @author 作者: LiuJunGuang * @version 创建时间：2011-11-9 下午03:47:59 */public class ControlServlet extends HttpServlet {public ControlServlet() {}public void doGet(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {DataSourceDAO dataSourceDAO = new DataSourceDAO();int countRecord = dataSourceDAO.count();request.setCharacterEncoding("UTF-8");// 得到当前页String currentPage = request.getParameter("page");if (currentPage == null)currentPage = "1";int cp = Integer.parseInt(currentPage);// 当前页码Page<Student> p = new Page<Student>(cp, countRecord);// 数据库中的查询结果List<Student> list = dataSourceDAO.findStudent(p.getStartIndex(),p.getOnePageCount());p.setList(list);// 设置结果集// 设置页码显示类型PageModel<Student> pageModel = new PageModel<Student>(p,"servlet/ControlServlet", PageModel.NUM_MODEL);request.setAttribute("pageObject", pageModel);getServletContext().getRequestDispatcher("/show.jsp").forward(request,response);}public void doPost(HttpServletRequest request, HttpServletResponse response)throws ServletException, IOException {doGet(request, response);}}

package cn.pdsu;import java.util.List;/** * 类说明：分页方法封装 *  * @author 作者: LiuJunGuang * @version 创建时间：2011-11-9 下午02:22:35 */public class Page<T> {/** * 总页数，通过总记录数和每页显示记录条数计算获得 */private int countPage;/** * 总记录数 */private int countRecord;/** * 当前页，默认是第一页 */private int currentPage = 1;/** * 结果列表 */private List<T> list = null;/** * 每页显示记录条数 ，默认是每页显示13条记录 */private int onePageCount = 3;/** * 开始索引，通过当前页和每页显示记录条数计算获得 */private int startIndex;public Page() {}/** * 两个参数的构造方法，调用该构造方法需要另行设置结果list *  * @param currentPage *            当前页 * @param countRecord *            总页数 */public Page(int currentPage, int countRecord) {this.currentPage = currentPage;this.countRecord = countRecord;calculate();}/** * 能够设置一页显示多少条记录的构造方法 *  * @param currentPage *            当前页 * @param countRecord *            总记录数 * @param onePageCount *            每页最多显示的记录条数 */public Page(int currentPage, int countRecord, int onePageCount) {super();this.countRecord = countRecord;this.currentPage = currentPage;this.onePageCount = onePageCount;calculate();}/** * 计算开始索引和总页数 */private void calculate() {// 计算开始索引this.startIndex = (currentPage - 1) * onePageCount;// 计算总页数this.countPage = (countRecord % onePageCount == 0) ? (countRecord / onePageCount): (countRecord / onePageCount + 1);}public int getCountPage() {return countPage;}public int getCountRecord() {return countRecord;}public int getCurrentPage() {return currentPage;}public List<T> getList() {return list;}public int getOnePageCount() {return onePageCount;}public int getStartIndex() {return startIndex;}public void setCountPage(int countPage) {this.countPage = countPage;}public void setCountRecord(int countRecord) {this.countRecord = countRecord;}public void setCurrentPage(int currentPage) {this.currentPage = currentPage;}public void setList(List<T> list) {this.list = list;}public void setOnePageCount(int onePageCount) {this.onePageCount = onePageCount;}public void setStartIndex(int startIndex) {this.startIndex = startIndex;}}

package cn.pdsu;/** * 开始页，结束页封装 *  * @author 作者：user * @version 创建时间：2011-7-19 上午03:08:25 */public class PageIndex {/** * 结束页 */private int endIndex;/** * 开始页 */private int startIndex;/** * 计算开始页和结束页 *  * @param viewpagecount *            页面中要显示的页面个数 * @param currentPage *            当前页 * @param totalpage *            总页面数 * @return PageIndex 记录开始页（startindex）和结束页（endindex） */public static PageIndex getPageIndex(int viewpagecount, int currentPage,int totalpage) {int startpage = currentPage- (viewpagecount % 2 == 0 ? viewpagecount / 2 - 1: viewpagecount / 2);int endpage = currentPage + viewpagecount / 2;if (startpage < 1) {startpage = 1;if (totalpage >= viewpagecount)endpage = viewpagecount;elseendpage = totalpage;}if (endpage > totalpage) {endpage = totalpage;if ((endpage - viewpagecount) > 0)startpage = endpage - viewpagecount + 1;elsestartpage = 1;}return new PageIndex(startpage, endpage);}public PageIndex(int startIndex, int endIndex) {this.startIndex = startIndex;this.endIndex = endIndex;}public int getEndIndex() {return endIndex;}public void setEndIndex(int endIndex) {this.endIndex = endIndex;}public int getStartIndex() {return startIndex;}public void setStartIndex(int startIndex) {this.startIndex = startIndex;}}

package cn.pdsu;import java.util.List;/** * 类说明：页码显示效果类 。1：TextModel “第一页 上一页 下一页 最后一页”；2：NumModel “第一页 2 3 4 最后一页”； *  * @author 作者: LiuJunGuang * @version 创建时间：2011-11-9 下午04:09:22 */public class PageModel<T> {/** * 文本类型：形如：“第一页 上一页 下一页 最后一页” */public static final int TEXT_MODEL = 1;/** * 数字类型：形如：NumModel “第一页 2 3 4 最后一页” */public static final int NUM_MODEL = 2;/** * 页码显示模型 */private int model = 1;/** * 页码连接URL，不需要添加页码参数 */private String url;/** * 页码信息的封装 */private Page page = null;/** * 模型类型的页码 */private StringBuffer strHtml = null;/** * 数字类型的页码模型中间数字显示个数，例如：第一页 1 2 3 4 5 最后一页，numCount = 5; 默认显示 5个数字 */private int numCount = 5;/** * 页码的模式默认的文字类型的样式 *  * @param page *            页面信息 * @param url *            页面的url地址 */public PageModel(Page page, String url) {super();this.url = url;this.page = page;}/** * 页码的模型 *  * @param page *            页面信息 * @param url *            页面的url地址 * @param model *            页码的显示样式 */public PageModel(Page page, String url, int model) {super();this.model = model;this.url = url;this.page = page;}/** * 页码的模型 *  * @param page *            页面信息 * @param url *            页面的url地址 * @param model *            页码的显示样式 * @param numCount *            数字类型的页码，共显示的个数 */public PageModel(Page page, String url, int model, int numCount) {super();this.model = model;this.url = url;this.page = page;this.numCount = numCount;}/** * 返回页面的模型 *  * @return */public String getPageModel() {// 组装页码模型createURL();return createModel();}/** * 构建URL */private void createURL() {url = url.contains("?") ? url + "&page=" : url + "?page=";}/** * 组装页码模型 */private String createModel() {strHtml = new StringBuffer();switch (model) {case TEXT_MODEL:// 文本模型buildTextModel();break;case NUM_MODEL:// 数字模型buildNumModel();break;default:// 文本模型buildTextModel();break;}return strHtml.toString();}/** * 组件数字类型的页码模型 */private void buildNumModel() {int currentPage = page.getCurrentPage();int countPage = page.getCountPage();strHtml.append("<table width='100%'  border='0' cellspacing='0' cellpadding='0'>").append("<tr><td height='24' align='center'>");// 构造格式：第一页 1 2 3 4 5 最后一页PageIndex pageIndex = PageIndex.getPageIndex(numCount, currentPage,countPage);// 不是第一页时，显示首页if (currentPage > 1) {strHtml.append("<a href='").append(url).append("1'>首页</a>  ");}if (currentPage <= countPage) {for (int i = pageIndex.getStartIndex(); i <= pageIndex.getEndIndex(); i++) {// 当前页加粗if (currentPage == i) {strHtml.append("<b>").append(i).append("</b>  ");} else {strHtml.append("<a href='").append(url).append(i).append("'>").append(i).append("</a>  ");}}// 不是最后一页显示末页if (currentPage < countPage) {strHtml.append("<a href='").append(url).append(countPage).append("'>末页</a>");}}strHtml.append("</td></tr></table>");}/** * 组件文本类型的页码 */private void buildTextModel() {int currentPage = page.getCurrentPage();int countPage = page.getCountPage();strHtml.append("<table width='100%'  border='0' cellspacing='0' cellpadding='0'>").append("<tr> <td height='24' align='center'>当前页数：[").append(currentPage).append("/").append(countPage).append("]  ");if (currentPage > 1) {strHtml.append("<a href='").append(url).append("1'>首页</a>").append("  <a href='").append(url).append(currentPage - 1).append("'>上一页</a>");}if (currentPage < countPage) {strHtml.append("  <a href='").append(url).append(currentPage + 1).append("'>下一页</a>  <a href='").append(url).append(countPage).append("'>末页</a>");}strHtml.append("</td></tr></table>");}public List<T> getList() {return page.getList();}}

<%@ page language="java" import="java.util.*" pageEncoding="GB18030"%><%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %><%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>    <base href="<%=basePath%>">    <title>分页技术</title>  </head>  <body>  <table border="1"  width="50%">  <tr><th>ID</th><th>姓名</th><th>性别</th><th>简介</th></tr>  <c:forEach items="${ pageObject.list}" var="student" >  <tr>  <td>${student.id }</td>  <td>${student.name }</td>  <td>${student.sex }</td>  <td>${student.resume }</td>  </tr>  </c:forEach>  </table>  ${ pageObject.pageModel}  </body></html>

运行结果图：