使用hibernate和struts2实现分页功能的示例

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：

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();
      
      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：

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" 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。