ammayjxf

 

Jpage分页——hibernate分页

 
[日期]: 2007-05-19  [来源]:   [作者]: zuoyefeng


名声显赫而招摇的数据持久层框架Hibernate,通过query.setFirstResult和query.setMaxResult来实现了对数据的分页,这个分页的实质在SqlServer中是TOP N的方法,Oracle是rownum<n方法。即直接通过SQL语句,来得到当前页所需的数据。

但是,Hibernate分页,并不能得到页脚,所以尚不通用。承接Jpage分页的方便性,写了这版分页,以方便已与群众。

下面,就是在Hibernate下的通用分页,属于Jpage分页的第三项功能。思路是定义一个Dao类,让其它数据库的dao都继承这个Dao类。


Dao类源文件:


 

package com.xdf.dao;

import java.io.*;
import java.sql.*;
import java.util.*;
import javax.servlet.http.*;
import org.hibernate.*;
import org.hibernate.criterion.Projections;

import com.xdf.hibernate.HibernateSessionFactory;

public class Dao {

 HttpServletRequest request;

 HttpServletResponse response;

 Session session;

 //定义List集合
 private List list;

 public int intCountic;

 public int PageSize;

 public int intPageCount;

 public int intPage;

 public String nowPage;

 public String HttpFile;
 


 //取得网址是的参数
 String PageParameter;

 public Dao(HttpServletRequest request, HttpServletResponse response) {

  this.request = request;
  this.response = response;
 }

 /*
  *******得到Session**********
  */
 public Session getSession() {
  session = HibernateSessionFactory.getSession();
  return session;

 }

 //添加数据
 public void add(Object obj) {
 }

 //修改数据
 public void mod(Object obj) {
 }

 //普通查询
 public List list() {
  return null;
 }

 
 
 public List jlist(Object query, String countsql)
 {

  
  Query q=null;
  Criteria cri=null;
  List li=null;
   
 
  boolean bool=false;;
  
  //得到记录总数
        if(query instanceof Query) {
         q=(Query)query;
         bool=true;
   intCountic = getCountJsql(countsql);
   
  }
       
        else if(query instanceof Criteria) {
         
         cri=(Criteria)query;
         li=cri.list();
         
      
         if(li.size()==0)
          intCountic=0;
         else
          intCountic=li.size();
       
  }
        else
        {
         
         System.out.println("出错提示:参数不正确");
         return null;
        }
       
    
       
  try
  {
  //每页记录数
      if (PageSize == 0)
   PageSize = 20;

  //获得url,如 /user/china.jsp
  HttpFile = request.getRequestURI();

  //获得当前页数
  nowPage = request.getParameter("pages");

  //取得网址是的参数
  PageParameter = this.urlPath(request);

  //如果没有pages参数,则让页数为1
  if (nowPage == null) {
   intPage = 1;
  }

  else {
   intPage = Integer.parseInt(nowPage);
   if (intPage < 1) {
    intPage = 1;
   }
  }

  

  //得到分页总数
  intPageCount = ((intCountic + PageSize) - 1) / PageSize;

  if (intPage > intPageCount) {
   intPage = intPageCount;
  }
    
//  得到list集合
  
   if(bool)
   list = q.setFirstResult((intPage - 1) * PageSize).setMaxResults(PageSize).list();    
   else
      list =cri.setFirstResult((intPage - 1) * PageSize).setMaxResults(PageSize).list(); 
  
 
  
  }
  catch(Exception ex)
  {
   ex.printStackTrace();
  }
  finally
  {
     
  }
  
  //将分页和页脚传到request中
        request.setAttribute("list", list);
        request.setAttribute("foot", PageFooter());
  return list;
 }
 
 
 
 
 
 
 public List jlist(Query query)
 {
  
    String[] str = query.getQueryString().split("from");  
    String countsql ="select count(*) from "+str[1].trim();  
    return jlist(query,countsql);  
  
 }
 
 public List jlist(Criteria query)
 {
  
  return jlist(query,"");
  
  
 }
 
 
 
 

 //汇总语句,得到记录总数
 public int getCountJsql(String countsql) {
  Query q = getSession().createQuery(countsql);
 
  List cc = q.list();
  Integer a = (Integer) cc.get(0);
  return a.intValue();
  
 
 }

 //页脚显示
 /**
  * 显示分页内容
  * @return
  */
 public String PageFooter() {

 
  if (list.size() <= 0) {
       return "<span style=\"color:#FF3300;font-size:14px;\">对不起,暂无记录!</span>";
        }
  
  String style = "<style> \n";
  style += ".page {color: #333333; background-color: #F3F3F3; height: 18px;width: 36px;";
  style += "border: 1px solid #333333;margin-right: 1px; margin-left: 1px;} \n";
  style += " .fytd {font-size: 12px; color: #333333;}\n";
  style += ".fy:link {color: #333333;text-decoration: underline;font-size: 12px;} \n";
  style += ".fy:visited {color: #333333;text-decoration: underline;font-size: 12px;} \n";
  style += ".fy:hover{color: #000000;text-decoration: none;border: 1px solid #999999;";
  style += "background-position: center center;font-size: 12px; background-color: #FFFFFF;} \n";
  style += ".fy:active {color: #000000;text-decoration: none;border: 1px solid #999999;";
  style += "background-position: center center;padding: 1px 1px 0px;font-size: 12px;background-color: #FFFFFF;} \n";
  style += "</style> \n";

  String str = "";
  int prev = intPage - 1;
  int next = intPage + 1;
  str = str
    + "<table width=100% border=0 cellspacing=0 cellpadding=1 class=fytd>";
  str = str + "<tr><td width=45%>共计:<font color=#FF3300>[" + intCountic
    + "]</font>条 <font color=#FF3300> [" + intPageCount
    + "]</font>页";
  str = str + " 第<font color=#FF3300>[" + getIntPage()
    + "]</font>页</td><td width=55%>";
  str = str
    + "<table width=275 border=0 align=right cellpadding=0 cellspacing=0 class=fytd>";
  //*******
  String pstr = HttpFile + "?" + PageParameter.replace("&pages=", "");
  pstr = pstr.replace("?pages=", "");
  str = str + "<form action=" + pstr
    + " name=formin method=post><tr><td width=195>";
  if (intPage > 1) {
   str = str + " <A href=../../" + HttpFile + "?" + PageParameter + "1"
     + " class=fy>[首页]</A> ";
  } else {
   str = str + " [首页] ";
  }
  if (intPage > 1) {
   str = str + " <A href=../../" + HttpFile + "?" + PageParameter + prev
     + " class=fy>[上一页]</A> ";
  } else {
   str = str + " [上一页] ";
  }
  if (intPage < intPageCount) {
   str = str + " <A href=../../" + HttpFile + "?" + PageParameter + next
     + " class=fy>[下一页]</A> ";
  } else {
   str = str + " [下一页] ";
  }
  if (intPageCount > 1 && intPage != intPageCount) {
   str = str + " <A href=../../" + HttpFile + "?" + PageParameter
     + intPageCount + " class=fy>[尾页]</A>";
  } else {
   str = str + " [尾页]";
  }
  str = str
    + "</td><td width=80 align=right><input name=pages type=text class=page value="
    + intPage
    + " size=3 maxlength=5 onkeyup=javascript:value=value.replace(/[^\\d]/g,'')>";
  str = str
    + "<input name=Submit2 type=submit class=page value=转到></td></tr></form></table>";
  str+="</td></tr></table>";
  return style + str;
 }

 /**
  * 对有参数的网址进行改造。。
  * 如 index.jsp?id=23&class=23
  */

 public String urlPath(HttpServletRequest request) {
  String path = "";
  String pagepath = "pages=";
  String url = request.getQueryString();

  //如果无参数
  if (url == null || url.equals("")) {
   return pagepath;
  }

  List lista = new ArrayList();
  StringTokenizer ss = new StringTokenizer(url, "&");

  while (ss.hasMoreTokens()) {
   String s = ss.nextToken();
   if (s.indexOf("pages") == -1)
    lista.add(s);
  }

  for (int i = 0; i < lista.size(); i++) {
   String param = "";
   try {
    param = new String(lista.get(i).toString().getBytes(
      "iso-8859-1"), "gb2312");
   } catch (UnsupportedEncodingException e) {

    e.printStackTrace();
   }
   path += param + "&";
  }

  return path + pagepath;

 }

 public int getIntCountic() {
  return intCountic;
 }

 public void setIntCountic(int intCountic) {
  this.intCountic = intCountic;
 }

 public int getIntPage() {
  return intPage;
 }

 public void setIntPage(int intPage) {
  this.intPage = intPage;
 }

 public int getIntPageCount() {
  return intPageCount;
 }

 public void setIntPageCount(int intPageCount) {
  this.intPageCount = intPageCount;
 }

 public String getNowPage() {
  return nowPage;
 }

 public void setNowPage(String nowPage) {
  this.nowPage = nowPage;
 }

 public int getPageSize() {
  return PageSize;
 }

 public void setPageSize(int pageSize) {
  PageSize = pageSize;
 }
}

/**
 * 注意事项:
 * 1、可传递Query或Critera参数
 * 2、传递Query对象时,不能使用包括?号的HQL语句。
 * 3、使用Critera时,是将所有数据读到List中,从而获得记录数,经测试5万条记录内,差别不明显
  *
 */


产品dao类(具体dao):


 

 

package com.xdf.dao;
import java.util.List;
import javax.servlet.http.*;
import org.hibernate.*;
import org.hibernate.Transaction;
import com.xdf.bean.PInfo;
import com.xdf.hibernate.HibernateSessionFactory;
import com.xdf.struts.form.*;
import javax.servlet.http.*;


public class PinfoDao extends Dao {
 
 public PinfoDao(HttpServletRequest request,HttpServletResponse response)
 {
  super(request,response);
 }
 

 //添加产品  
 public void add(Object po) { }
 //修改产品  
 public void mod(Object po) { }

  //分页查询
  public List list() {  
  Query query =getSession().createQuery("from PInfo");

  //想使用分页,将Query作为参数,传给jlist方法就可以了,这时就可以得到列表和页脚。
  //HQL查询、条件查询都返回Query对象,所以都可以。
   List li=jlist(query);
   //或者 List li=jlist(query,PInfo);
  return li;  
  }


 //汇总查询
public List count()
{
return null;
}

  
}



3、Struts的Action调用dao:

 
public ActionForward execute(ActionMapping mapping, ActionForm form,
   HttpServletRequest request, HttpServletResponse response) {
  System.out.println("aabbcc");
  PinfoDao dao = new PinfoDao(request,response);
  dao.list();
  return mapping.findForward("list");
  
 }



4、在JSP中显示:这里采用的是DIV布局

 
  <ul>
   <li>产品名称</li>
   <li>产品类别</li>
   <li>产品价格</li>
   <li>操    作</li>
   </ul>
  
 
   <logic:iterate id="da" name="list">
    <ul>
   <li><bean:write name="da" property="PName" /></li>
   <li><bean:write name="da" property="PType" /></li>
   <li><bean:write name="da" property="PPrice" /></li>
   <li><a href="prod.do id=<bean:write name="da" property="PId" />">删除</a></li>
   </ul>
   </logic:iterate>
  
   <ul>
   <li>
    <bean:write name="foot" filter="false"></bean:write>
   </li>
   </ul>




示例下载:
upload/2007_05/07051911442616.rar



也就是说,你把Dao类,拷过去,让你自己的具体的dao继承这个类,就可以

posted on 2009-08-19 23:09 ammay 阅读(309) 评论(0)  编辑  收藏


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