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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,在这里,首先要感谢
http://www.blogjava/rongxh7/archive/2008/11/29/243456.html
这位博友发表的博文,通过对他代码的阅读,从而自己实现了网页分页功能,以下是源代码,如大家有需要,可以回复我,我会放出源代码供大家下载!
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 */ @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(); txmit(); } 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(); txmit(); } 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
*/
@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:
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:
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:
转载于:https://blog.51cto/3237526/1606257
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