使用hibernate和struts2實現分頁功能的示例

想著每天能學個新東西，今天準備了這個hibernate+struts2實現頁面的分頁功能，以下是源代碼。

1.DAO層接口的設計，定義一個PersonDAO接口，裡面聲明了兩個方法：

 public interface PersonDAO{ public List<Person> queryByPage(String hql, int offset, int pageSize); public int getAllRowCount(String hql);}

2.DAO層接口的實現類PersonDAOImpl類，將其兩個方法實現出來：

 public class PersonDAOImpl implements PersonDAO{ /** * 通過hql語句得到數據庫中記錄總數*/ @Override public int getAllRowCount(String hql) { Session session = HibernateUtil.openSession(); Transaction tx = null; int allRows = 0; try { tx = session.beginTransaction(); Query query = session.createQuery(hql); allRows = query.list().size(); tx.commit(); } catch (Exception e) { if(tx != null) { tx.rollback(); } e.printStackTrace(); } finally { HibernateUtil.closeSession(session); } return allRows; } /** * 使用hibernate提供的分頁功能，得到分頁顯示的數據*/ @SuppressWarnings("unchecked") @Override public List<Person> queryByPage(String hql, int offset, int pageSize) { Session session = HibernateUtil.openSession(); Transaction tx = null; List<Person> list = null; try { tx = session.beginTransaction(); Query query = session.createQuery(hql).setFirstResult(offset).setMaxResults(pageSize); list = query.list(); tx.commit(); } catch (Exception e) { if(tx != null) { tx.rollback(); } e.printStackTrace(); } finally { HibernateUtil.closeSession(session); } return list; }}

3.定義了一個PageBean(每一頁所需要的內容都存放在這個PageBean裡面)，裡面用來存放網頁每一頁顯示的內容：

 public class PageBean{ private List<Person> list; //通過hql從數據庫分頁查詢出來的list集合private int allRows; //總記錄數private int totalPage; //總頁數private int currentPage; //當前頁public List<Person> getList() { return list; } public void setList(List<Person> list) { this.list = list; } public int getAllRows() { return allRows; } public void setAllRows(int allRows) { this.allRows = allRows; } public int getTotalPage() { return totalPage; } public void setTotalPage(int totalPage) { this.totalPage = totalPage; } public int getCurrentPage() { return currentPage; } public void setCurrentPage(int currentPage) { this.currentPage = currentPage; } /** * 得到總頁數* @param pageSize 每頁記錄數* @param allRows 總記錄數* @return 總頁數*/ public int getTotalPages(int pageSize, int allRows) { int totalPage = (allRows % pageSize == 0)? (allRows / pageSize): (allRows / pageSize) + 1; return totalPage; } /** * 得到當前開始記錄號* @param pageSize 每頁記錄數* @param currentPage 當前頁* @return */ public int getCurrentPageOffset(int pageSize, int currentPage) { int offset = pageSize * (currentPage - 1); return offset; } /** * 得到當前頁， 如果為0 則開始第一頁，否則為當前頁* @param page * @return */ public int getCurPage(int page) { int currentPage = (page == 0)? 1: page; return currentPage; } }

4.Service層接口設計，定義一個PersonService接口，裡面聲明了一個方法，返回一個PageBean：

 public interface PersonService{ public PageBean getPageBean(int pageSize, int page);}

5.Service層接口實現類PersonServiceImpl類，實現唯一的方法：

 public class PersonServiceImpl implements PersonService{ private PersonDAO personDAO = new PersonDAOImpl(); /** * pageSize為每頁顯示的記錄數* page為當前顯示的網頁*/ @Override public PageBean getPageBean(int pageSize, int page) { PageBean pageBean = new PageBean(); String hql = "from Person"; int allRows = personDAO.getAllRowCount(hql); int totalPage = pageBean.getTotalPages(pageSize, allRows); int currentPage = pageBean.getCurPage(page); int offset = pageBean.getCurrentPageOffset(pageSize, currentPage); List<Person> list = personDAO.queryByPage(hql, offset, pageSize); pageBean.setList(list); pageBean.setAllRows(allRows); pageBean.setCurrentPage(currentPage); pageBean.setTotalPage(totalPage); return pageBean; }}

6.Action層設計，定義一個PersonAction：

 public class PersonAction extends ActionSupport{ private PersonService personService = new PersonServiceImpl(); private int page; public int getPage() { return page; } public void setPage(int page) { this.page = page; } @Override public String execute() throws Exception { //表示每頁顯示5條記錄，page表示當前網頁PageBean pageBean = personService.getPageBean(5, page); HttpServletRequest request = ServletActionContext.getRequest(); request.setAttribute("pageBean", pageBean); return SUCCESS; }}

7.輔助類設計，HibernateUtil:

 public class HibernateUtil{ private static SessionFactory sessionFactory; static { sessionFactory = new Configuration().configure().buildSessionFactory(); } public static Session openSession() { Session session = sessionFactory.openSession(); return session; } public static void closeSession(Session session) { if(session != null) { session.close(); } } }

8.最後也就是分頁頁面顯示pagePerson.jsp：

 <%@ page language="java" import="java.util.*" pageEncoding="UTF-8"%><%@ taglib prefix="s" uri="/struts-tags"%><html> <head> <base href="<%=basePath%>"> <title>My JSP 'pagePerson.jsp' starting page</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"> <script type="text/javascript"> function validate() { var page = document.getElementsByName("page")[0].value; if(page > <s:property value="#request.pageBean.totalPage"/>) { alert("你輸入的頁數大於最大頁數，頁面將跳轉到首頁！"); window.document.location.href = "personAction"; return false; } return true; } </script> </head> <body> <h1><font color="blue">分頁查詢</font></h1><hr> <table align="center" bordercolor="yellow"> <tr> <th>序號</th> <th>姓名</th> <th>年齡</th> </tr> <s:iterator value="#request.pageBean.list" id="person"> <tr> <th><s:property value="#person.id"/></th> <th><s:property value="#person.name"/></th> <th><s:property value="#person.age"/></th> </tr> </s:iterator> </table> <center> <font size="5">共<font color="red"><s:property value="#request.pageBean.totalPage"/></font>頁</font> <font size="5">共<font color="red"><s:property value="#request.pageBean.allRows"/></font>條記錄</font><br><br> <s:if test="#request.pageBean.currentPage == 1"> 首頁上一頁</s:if> <s:else> <a href="personAction.action">首頁</a> <a href="personAction.action?page=<s:property value="#request.pageBean.currentPage - 1"/>">上一頁</a> </s:else> <s:if test="#request.pageBean.currentPage != #request.pageBean.totalPage"> <a href="personAction.action?page=<s:property value="#request.pageBean.currentPage + 1"/>">下一頁</a> <a href="personAction.action?page=<s:property value="#request.pageBean.totalPage"/>">尾頁</a> </s:if> <s:else> 下一頁尾頁</s:else> </center><br> <center> <form action="personAction" onsubmit="return validate();"> <font size="4">跳轉至</font> <input type="text" size="2" name="page">頁<input type="submit" value="跳轉"> </form> </center> </body></html>

至此，hibernate+struts2實現網頁分頁功能代碼部分就完畢了，像hibernate與struts的配置文件就不列出來了，那些都不是重點！

頁面效果如下:

以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持武林網。