struts2+spring+hibernate 实现分页

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>&nbsp;&nbsp;
        <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&nbsp;&nbsp;&nbsp;上一页
        </s:if>

        <s:else>
            <a href="NewsAction.action">首页</a>
            &nbsp;&nbsp;&nbsp;
            <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>
            &nbsp;&nbsp;&nbsp;
            <a href="NewsAction.action?page=<s:property value="#request.pageBean.totalPage"/>">尾页</a>
        </s:if>

        <s:else>
            下一页&nbsp;&nbsp;&nbsp;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！