1.DAO层接口的设计，定义一个PersonDAO接口，里面声明了两个方法：
public interface PersonDAO {public List<Person> queryByPage(String hql, int offset, int pageSize);public int getAllRowCount(String hql); }
2.DAO层接口的实现类PersonDAOImpl类，将其两个方法实现出来：
public class PersonDAOImpl implements PersonDAO {/*** 通过hql语句得到数据库中记录总数*/@Overridepublic 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提供的分页功能，得到分页显示的数据*/@SuppressWarnings("unchecked")@Overridepublic 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.定义了一个PageBean(每一页所需要的内容都存放在这个PageBean里面)，里面用来存放网页每一页显示的内容：
public class PageBean {private List<Person> list; //通过hql从数据库分页查询出来的list集合private int allRows; //总记录数private int totalPage; //总页数private int currentPage; //当前页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;}/*** 得到总页数* @param pageSize 每页记录数* @param allRows 总记录数* @return 总页数*/public int getTotalPages(int pageSize, int allRows){int totalPage = (allRows % pageSize == 0)? (allRows / pageSize): (allRows / pageSize) + 1;return totalPage;}/*** 得到当前开始记录号* @param pageSize 每页记录数* @param currentPage 当前页* @return*/public int getCurrentPageOffset(int pageSize, int currentPage){int offset = pageSize * (currentPage - 1);return offset;}/*** 得到当前页， 如果为0 则开始第一页，否则为当前页* @param page* @return*/public int getCurPage(int page){int currentPage = (page == 0)? 1: page;return currentPage;}}
4.Service层接口设计，定义一个PersonService接口，里面声明了一个方法，返回一个PageBean：
public interface PersonService {public PageBean getPageBean(int pageSize, int page); }
5.Service层接口实现类PersonServiceImpl类，实现唯一的方法：
public class PersonServiceImpl implements PersonService {private PersonDAO personDAO = new PersonDAOImpl();/*** pageSize为每页显示的记录数* page为当前显示的网页*/@Overridepublic 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层设计，定义一个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;}@Overridepublic String execute() throws Exception{//表示每页显示5条记录，page表示当前网页PageBean pageBean = personService.getPageBean(5, page);HttpServletRequest request = ServletActionContext.getRequest();request.setAttribute("pageBean", pageBean);return SUCCESS;} }
7.辅助类设计，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.最后也就是分页页面显示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("你输入的页数大于最大页数，页面将跳转到首页！");window.document.location.href = "personAction";return false;}return true;}</script></head><body><h1><font color="blue">分页查询</font></h1><hr><table border="1" align="center" bordercolor="yellow" width="50%"><tr><th>序号</th><th>姓名</th><th>年龄</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>页 </font> <font size="5">共<font color="red"><s:property value="#request.pageBean.allRows"/></font>条记录</font><br><br><s:if test="#request.pageBean.currentPage == 1">首页 上一页</s:if><s:else><a href="personAction.action">首页</a> <a href="personAction.action?page=<s:property value="#request.pageBean.currentPage - 1"/>">上一页</a></s:else><s:if test="#request.pageBean.currentPage != #request.pageBean.totalPage"><a href="personAction.action?page=<s:property value="#request.pageBean.currentPage + 1"/>">下一页</a> <a href="personAction.action?page=<s:property value="#request.pageBean.totalPage"/>">尾页</a></s:if><s:else>下一页 尾页</s:else></center><br><center><form action="personAction" οnsubmit="return validate();"><font size="4">跳转至</font><input type="text" size="2" name="page">页<input type="submit" value="跳转"></form></center></body> </html>
至此，hibernate+struts2实现网页分页功能代码部分就完毕了，像hibernate与struts的配置文件就不列出来了，那些都不是重点！
页面效果如下:
