使用hibernate和struts2實現(xiàn)分頁功能的示例

更新時間：2017年01月04日 15:30:19 作者：xiaoluo501395377

本篇文章主要介紹了使用hibernate和struts2實現(xiàn)分頁功能，小編覺得挺不錯的，現(xiàn)在分享給大家，也給大家做個參考。一起跟隨小編過來看看吧

想著每天能學個新東西，今天準備了這個hibernate+struts2實現(xiàn)頁面的分頁功能，以下是源代碼。

1.DAO層接口的設計，定義一個PersonDAO接口，里面聲明了兩個方法：

public interface PersonDAO
{
  public List<Person> queryByPage(String hql, int offset, int pageSize);
  
  public int getAllRowCount(String hql);
}

2.DAO層接口的實現(xiàn)類PersonDAOImpl類，將其兩個方法實現(xiàn)出來：

public class PersonDAOImpl implements PersonDAO
{
  /**
   * 通過hql語句得到數(shù)據(jù)庫中記錄總數(shù)
   */
  @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提供的分頁功能，得到分頁顯示的數(shù)據(jù)
   */
  @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.定義了一個PageBean(每一頁所需要的內(nèi)容都存放在這個PageBean里面)，里面用來存放網(wǎng)頁每一頁顯示的內(nèi)容：

public class PageBean
{
  private List<Person> list; //通過hql從數(shù)據(jù)庫分頁查詢出來的list集合
  
  private int allRows; //總記錄數(shù)
  
  private int totalPage; //總頁數(shù)
  
  private int currentPage; //當前頁

  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;
  }
  
  /**
   * 得到總頁數(shù)
   * @param pageSize 每頁記錄數(shù)
   * @param allRows 總記錄數(shù)
   * @return 總頁數(shù)
   */
  public int getTotalPages(int pageSize, int allRows)
  {
    int totalPage = (allRows % pageSize == 0)? (allRows / pageSize): (allRows / pageSize) + 1;
    
    return totalPage;
  }
  
  /**
   * 得到當前開始記錄號
   * @param pageSize 每頁記錄數(shù)
   * @param currentPage 當前頁
   * @return
   */
  public int getCurrentPageOffset(int pageSize, int currentPage)
  {
    int offset = pageSize * (currentPage - 1);
    
    return offset;
  }
  
  /**
   * 得到當前頁， 如果為0 則開始第一頁，否則為當前頁
   * @param page
   * @return
   */
  public int getCurPage(int page)
  {
    int currentPage = (page == 0)? 1: page;
    
    return currentPage;
  }
  
}

4.Service層接口設計，定義一個PersonService接口，里面聲明了一個方法，返回一個PageBean：

public interface PersonService
{
  public PageBean getPageBean(int pageSize, int page);
}

5.Service層接口實現(xiàn)類PersonServiceImpl類，實現(xiàn)唯一的方法：

public class PersonServiceImpl implements PersonService
{
  private PersonDAO personDAO = new PersonDAOImpl();
  
  /**
   * pageSize為每頁顯示的記錄數(shù)
   * page為當前顯示的網(wǎng)頁
   */
  @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層設計，定義一個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
  {
    //表示每頁顯示5條記錄，page表示當前網(wǎng)頁
    PageBean pageBean = personService.getPageBean(5, page);
    
    HttpServletRequest request = ServletActionContext.getRequest();
    
    request.setAttribute("pageBean", pageBean);
    
    return SUCCESS;
  }
}

7.輔助類設計，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.最后也就是分頁頁面顯示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("你輸入的頁數(shù)大于最大頁數(shù)，頁面將跳轉(zhuǎn)到首頁！");
        
        window.document.location.href = "personAction";
        
        return false;
      }
      
      return true;
    }
  
  </script>

 </head>
 
 <body>

  <h1><font color="blue">分頁查詢</font></h1><hr>
  
  <table border="1" align="center" bordercolor="yellow" width="50%">
  
    <tr>
      <th>序號</th>
      <th>姓名</th>
      <th>年齡</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>頁 </font>&nbsp;&nbsp;
    <font size="5">共<font color="red"><s:property value="#request.pageBean.allRows"/></font>條記錄</font><br><br>
    
    <s:if test="#request.pageBean.currentPage == 1">
      首頁&nbsp;&nbsp;&nbsp;上一頁
    </s:if>
    
    <s:else>
      <a href="personAction.action">首頁</a>
      &nbsp;&nbsp;&nbsp;
      <a href="personAction.action?page=<s:property value="#request.pageBean.currentPage - 1"/>">上一頁</a>
    </s:else>
    
    <s:if test="#request.pageBean.currentPage != #request.pageBean.totalPage">
      <a href="personAction.action?page=<s:property value="#request.pageBean.currentPage + 1"/>">下一頁</a>
      &nbsp;&nbsp;&nbsp;
      <a href="personAction.action?page=<s:property value="#request.pageBean.totalPage"/>">尾頁</a>
    </s:if>
    
    <s:else>
      下一頁&nbsp;&nbsp;&nbsp;尾頁
    </s:else>
  
  </center><br>
  
  <center>
    
    <form action="personAction" onsubmit="return validate();">
      <font size="4">跳轉(zhuǎn)至</font>
      <input type="text" size="2" name="page">頁
      <input type="submit" value="跳轉(zhuǎn)">
    </form>
    
  </center>
  
 </body>
</html>

至此，hibernate+struts2實現(xiàn)網(wǎng)頁分頁功能代碼部分就完畢了，像hibernate與struts的配置文件就不列出來了，那些都不是重點！

頁面效果如下: