想着每天能学个新东西,今天准备了这个hibernate+struts2实现页面的分页功能,以下是源代码。
1.DAO层接口的设计,定义一个PersonDAO接口,里面声明了两个方法:
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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:
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public class PersonDAOImpl implements PersonDAO { /** * 通过hql语句得到数据库中记录总数 */ @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提供的分页功能,得到分页显示的数据 */ @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:
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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:
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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:
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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 */ @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层设计,定义一个PersonAction:
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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:
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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:
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<%@ 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" onsubmit= "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:
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持服务器之家。
原文链接:http://www.cnblogs.com/xiaoluo501395377/archive/2012/10/18/2730073.html