在这里要感谢下这位博友发表的博文
http://www.blogjava.net/rongxh7/archive/2008/11/29/243456.html
通过对他代码的阅读，从而自己实现了网页分页功能，下面给大家分享下我的代码
1.entity实体类
我项目例子的实体类叫News
2.DAO接口的设计，定义一个NewsDAO接口，里面声明了两个方法：
public interface NewsDAO { public int getAllRowCount(String hql); public List<News> queryByPage(String hql, int offset, int pageSize); }
3.DAO层接口的实现类NewsDAOImpl类，并实现接口的两个方法：
public class NewsDAOImpl implements NewsDAO{ //注解注入属性实例 @Resource(name="mySessionFactory_mysql") private SessionFactory sessionFactory; /** * 通过hql语句得到数据库中记录总数 */ @Override public int getAllRowCount(String hql) { Session session=sessionFactory.openSession(); Transaction tx=null; int allRows=0; try{ tx=session.beginTransaction(); Query query=session.createQuery(hql); allRows=query.getResultList().size(); tx.commit(); }catch (Exception e){ if(tx != null) { tx.rollback(); } e.printStackTrace(); }finally{ if(session!=null){ session.close(); } } return allRows; } /** * 使用hibernate提供的分页功能，得到分页显示的数据 */ @Override public List<News> queryByPage(String hql, int offset, int pageSize) { Session session=sessionFactory.openSession(); Transaction tx=null; List<News> list=null; try{ tx=session.beginTransaction(); Query query=session.createQuery(hql).setFirstResult(offset).setMaxResults(pageSize); list=query.getResultList(); tx.commit(); }catch(Exception e){ if(tx != null) { tx.rollback(); } e.printStackTrace(); }finally{ if(session!=null){ session.close(); } } return list; } }
4.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<News> 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<News> getList() { return list; } public void setList(List<News> 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; } }
5.Service层接口设计，定义一个NewsService接口，里面声明了一个方法，返回一个PageBean：
public interface NewsService { public PageBean getPageBean(int pageSize,int page); }
6.Service层接口实现类NewsServiceImpl类，实现NewsService接口的方法：
public class NewsServiceImpl implements NewsService{ //注解注入属性实例 @Resource(name="myNewsDao") private NewsDAO newsDao; @Resource(name="myPageBean") private PageBean pageBean; /** * 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) { String hql="from News"; //总记录数 int allRows=newsDao.getAllRowCount(hql); //总页数 int totalPage=pageBean.getTotalPages(pageSize,allRows); //当前页 int currentPage=pageBean.getCurPage(page); //锚点(从第几条数据开始查询) int offset=pageBean.getCurrentPageOffset(pageSize, currentPage); List<News> list = newsDao.queryByPage(hql, offset, pageSize); pageBean.setList(list); pageBean.setAllRows(allRows); pageBean.setCurrentPage(currentPage); pageBean.setTotalPage(totalPage); return pageBean; } }
7.Action层设计，定义一个NewsAction：
public class NewsAction extends ActionSupport { //注解注入属性实例 @Resource(name="myNewsService") private NewsService newsService; private int page; public int getPage() { return page; } public void setPage(int page) { this.page = page; } @Override public String execute(){ //表示每页显示5条记录，page表示当前网页 PageBean pageBean = newsService.getPageBean(5, page); HttpServletRequest request = ServletActionContext.getRequest(); request.setAttribute("pageBean", pageBean); return SUCCESS; } }
9.配置struts.xml文件
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE struts PUBLIC "-//Apache Software Foundation//DTD Struts Configuration 2.3//EN" "http://struts.apache.org/dtds/struts-2.3.dtd"> <struts> <!-- 告知Struts2运行时使用Spring来创建对象 --> <constant name="struts.objectFactory" value="spring" /> <package name="mypck001" extends="struts-default" namespace="/"> <action name="NewsAction" class="myNewsAction" method="execute"> <result name="success">/WEB-INF/jsp/index.jsp</result> </action> </package> </struts>
10.配置applicationContext.xml文件
<?xml version="1.0" encoding="UTF-8"?> <beans xmlns="http://www.springframework.org/schema/beans" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:p="http://www.springframework.org/schema/p" xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:jee="http://www.springframework.org/schema/jee" xmlns:tx="http://www.springframework.org/schema/tx" xsi:schemaLocation=" http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-4.2.xsd http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-4.2.xsd http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-4.2.xsd http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee-4.2.xsd http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-4.2.xsd"> <!-- 原理：自动注入processor解析器，用来解析注解 --> <context:annotation-config /> <context:property-placeholder location="classpath:jdbc.properties" /> <bean id="myNewsAction" class="sshPage.action.NewsAction" scope="prototype"> </bean> <bean id="myNewsService" class="sshPage.service.NewsServiceImpl" scope="prototype"> </bean> <bean id="myNewsDao" class="sshPage.dao.NewsDAOImpl" scope="prototype"> </bean> <bean id="myPageBean" class="sshPage.pageBean.PageBean" scope="prototype"> </bean> <bean id="mySessionFactory_mysql" class="org.springframework.orm.hibernate5.LocalSessionFactoryBean" > <property name="dataSource" ref="mysql_DataSource"></property> <property name="hibernateProperties"> <props> <prop key="hibernate.dialect">org.hibernate.dialect.MySQL5Dialect</prop> <prop key="hibernate.show_sql">true</prop> <prop key="hibernate.format_sql">true</prop> <prop key="hibernate.connection.autocommit">false</prop> <prop key="hibernate.hbm2ddl.auto">update</prop> </props> </property> <property name="mappingResources"> <list> <value>sshPage/entity/News.hbm.xml</value> </list> </property> </bean> <!-- 数据库连接池 mysql_DataSource--> <!-- c3p0 --> <bean id="mysql_DataSource" class="com.mchange.v2.c3p0.ComboPooledDataSource"> <property name="driverClass" value="${mysql.driver}" /> <property name="jdbcUrl" value="${mysql.url}" /> <property name="user" value="${mysql.userName}" /> <property name="password" value="${mysql.password}" /> <property name="idleConnectionTestPeriod" value="300"></property> <property name="maxIdleTime" value="900"></property> <property name="maxPoolSize" value="2"></property> </bean> </beans>
11.最后也就是JSP页面index.jsp：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="/struts-tags" prefix="s" %> <%@ page import="java.util.*"%> <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> <title>Insert title here</title> <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 = "NewsAction"; 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>Id</th> <th>Title</th> <th>Content</th> <th>Begintime</th> <th>Username</th> </tr> <s:iterator value="#request.pageBean.list" id="news"> <tr> <td><s:property value="#news.id"/></td> <td><s:property value="#news.title"/></td> <td><s:property value="#news.content"/></td> <td><s:date name="#news.begintime" format="yyyy年MM月dd日"></s:date></td> <td><s:property value="#news.username"></s:property></td> </tr> </s:iterator> </table> <b></b> <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> <font size="5">第<font color="red"><s:property value="#request.pageBean.currentPage"/></font>页 </font> <s:if test="#request.pageBean.currentPage == 1"> 首页 上一页 </s:if> <s:else> <a href="NewsAction.action">首页</a> <a href="NewsAction.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="NewsAction.action?page=<s:property value="#request.pageBean.currentPage + 1"/>">下一页</a> <a href="NewsAction.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="NewsAction" onsubmit="return validate();"> <font size="4">跳转至</font> <input type="text" size="2" value='<s:property value="#request.pageBean.currentPage"/>' name="page">页 <input type="submit" value="跳转"> </form> </center> </body> </html>
页面效果图如下：
实现分页就差不多到这了，如果有不懂的地方，可以评论区给我留言，谢谢！