struts+hibernate的通用分页程序

struts+hibernate的通用分页程序

2007-06-27 14:18

Jpage分页—struts+hibernate的通用分页程序

本文源自昨夜风网站(www.zuoyefeng.com )

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>