Action做分页

1、1.Pager类 分页公共类功能：Pager类用于计算首页、前一页、下一页、尾页的在数据库中的起始行，当前的页码。package com.jpcf.db.helper;import java.math.*;public class Pager private int totalRows; /总行数 private int pageSize = 10; /每页显示的行数 private int currentPage; /当前页号 private int totalPages; /总页数 private int startRow; /当前页在数据库中的起始行 public Pager() pub

2、lic Pager(int _totalRows) totalRows = _totalRows; totalPages=totalRows/pageSize; int mod=totalRows%pageSize; if(mod>0) totalPages+; currentPage = 1; startRow = 0; 推荐精选 public int getStartRow() return startRow; public int getTotalPages() return totalPages; public int getCurrentPage() return curren

3、tPage; public int getPageSize() return pageSize; public void setTotalRows(int totalRows) this.totalRows = totalRows; public void setStartRow(int startRow) this.startRow = startRow; public void setTotalPages(int totalPages) this.totalPages = totalPages; public void setCurrentPage(int currentPage) 推荐精

4、选 this.currentPage = currentPage; public void setPageSize(int pageSize) this.pageSize = pageSize; public int getTotalRows() return totalRows; public void first() /首页 currentPage = 1; startRow = 0; public void previous() /上一页 if (currentPage = 1) return; currentPage-; startRow = (currentPage - 1) * p

5、ageSize; public void next() /下一页 if (currentPage < totalPages) currentPage+;推荐精选 startRow = (currentPage - 1) * pageSize; public void last() /尾页 currentPage = totalPages; startRow = (currentPage - 1) * pageSize; public void refresh(int _currentPage) currentPage = _currentPage; if (currentPage >

6、; totalPages) last(); 2.PagerHelp类 功能：PageHelper这个类，用于从页面上取得参数进行相应的业务逻辑处理package com.jpcf.db.helper;import javax.servlet.http.*;public class PagerHelper public static Pager getPager(HttpServletRequest httpServletRequest,推荐精选 int totalRows) /定义pager对象，用于传到页面 Pager pager = new Pager(totalRows); /从Requ

7、est对象中获取当前页号 String currentPage=httpServletRequest.getParameter("currentPage"); /如果当前页号为空，表示为首次查询该页 /如果不为空，则刷新pager对象，输入当前页号等信息 if (currentPage != null) pager.refresh(Integer.parseInt(currentPage); /获取当前执行的方法，首页，前一页，后一页，尾页。 String pagerMethod = httpServletRequest.getParameter("pageMet

8、hod"); if (pagerMethod != null) if (pagerMethod.equals("first") pager.first(); elseif (pagerMethod.equals("previous")pager.previous(); else if (pagerMethod.equals("next")pager.next(); else if (pagerMethod.equals("last") pager.last();return pager;推荐精选 3.部门

9、DAO类中的方法 功能说明：利用hibernate中的 setFirstResult(parma)和.setMaxResults(parma)进行分页上线和下线的约束 /* * param pageSize 每页显示几条数据; * param startRow 从数据库哪条数据开始显示 */public List findWithPage(int startRow,int pageSize) List list = null;try list=getSession().createQuery("from Users").setFirstResult(startRow).se

10、tMaxResults(pageSize).list();System.out.println(list); catch (RuntimeException re) throw re ;推荐精选return list;/* * 统计数据库中的记录 */public int getRows() int totalRows = 0;try getSession().getTransaction().begin();/查询语句select count(*) from VehicleProperty 也可以换成你需要的任意的条件(select count(*) from VehicleProperty

11、 where .)long number= (Long)getSession().createQuery("select count(*) from VehicleProperty").uniqueResult();totalRows=(int)number;getSession().getTransaction().commit(); catch (RuntimeException re) re.printStackTrace();getSession().getTransaction().rollback();throw re;推荐精选return totalRows;

12、4.Action 下面是在Action中用到的代码： public void findWithPage(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException int totalRows;/记录总行数 totalRows=dao.getRows(); try /通过PagerHelper类来获取用于输出到页面的pager对象 Pager pager=PagerHelper.getPager(request,totalRows); List list=(List)

13、dao.findWithPage( pager.getStartRow(),pager.getPageSize(); request.setAttribute("list", list); request.setAttribute("totalPage", pager.getTotalPages(); request.setAttribute("currentPage", pager.getCurrentPage();推荐精选 request.getRequestDispatcher("/jsp/view.jsp"

14、).forward(request, response); catch (Exception e) e.printStackTrace(); response.sendRedirect(request.getContextPath()+"/jsp/error.jsp"); 5.JSP页面(view.jsp)<% page language="java" import="java.util.*" pageEncoding="GB2312" contentType="text/html; charset

15、=GB2312"%><%taglib prefix="c" uri="<!DOCTYPE HTML PUBLIC "-/W3C/DTD HTML 4.01 Transitional/EN"><html> <head>推荐精选 <title>view.jsp</title><meta http-equiv="pragma" content="no-cache"><meta http-equiv="c

16、ache-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"> </hea

17、d> <body> <table align="center" border="1" width="60%"> <tr> <td>员工id</td><td>员工姓名</td><td>密码</td><td>员工住址</td><td>电话</td><td>删除</td><td>修改</td> </tr> <c:if

18、 test="$not empty list"> <c:forEach items="$list" var="users"> <tr> <td>$users.id</td> <td>$users.userName</td> <td>$users.password</td> <td>$users.address</td> <td>$users.telphone</td>推荐精选 <t

19、d><a href="./servlet/ActionServlet?method=delete&del_id=$users.id">删除</a></td> <td><a href="./servlet/ActionServlet?method=getObject&get_id=$users.id">修改</a></td> </tr> </c:forEach> <tr> <td colspan="7" align="center"> 第$currentPage页/共$totalPage页 <a h