Hibernate实现分页

1.Pager.java

package com.fzw.util;

public class Pager {
   private int totalRows;
   private int totalPages;
   private int pageSize=5;
   private int currentPage;
   private int startRow; //定义为前一页的最后一行为开始行
  
   public Pager( int totalRows){ //初始化
     this.totalRows = totalRows;
     this.totalPages = totalRows/pageSize;
     int mod = totalRows%pageSize;
     if(mod>0){ //如果不能整除，totalPages加1
       this.totalPages++;
    }
     this.currentPage = 1;
    startRow = 0; //起始行为第0行
  }

   public int getCurrentPage() {
     return currentPage;
  }

   public void setCurrentPage( int currentPage) {
     this.currentPage = currentPage;
  }

   public int getPageSize() {
     return pageSize;
  }

   public void setPageSize( int pageSize) {
     this.pageSize = pageSize;
  }

   public int getStartRow() {
     return startRow;
  }

   public void setStartRow( int startRow) {
     this.startRow = startRow;
  }

   public int getTotalPages() {
     return totalPages;
  }

   public void setTotalPages( int totalPages) {
     this.totalPages = totalPages;
  }

   public int getTotalRows() {
     return totalRows;
  }

   public void setTotalRows( int totalRows) {
     this.totalRows = totalRows;
  }
  
   public void first(){ //获得第一页
    currentPage = 1;
    startRow = 0;
  }
  
   public void previous(){ //获得前一页
     if(currentPage == 1){ //如果当前页是第一页，那么什么也不做
       return;
    }
    currentPage--;
    startRow = (currentPage-1)*pageSize;
  }
  
   public void next(){ //获得下一页
     if(currentPage       currentPage++;
    }
    startRow = (currentPage-1)*pageSize;
  }
  
   public void last(){ //获得最后一页
    currentPage = totalPages;
    startRow = (currentPage-1)*pageSize;
  }
  
   public void refresh( int currentPage){ //获得指定页面
     this.currentPage = currentPage;
     if(currentPage > totalPages){
      last();
    }
  }
}

2.PagerHelper.java

package com.fzw.util;

import javax.servlet.http.HttpServletRequest;

public class PagerHelper {

   public static Pager getPager(HttpServletRequest request, int totalRows) {
    Pager pager = new Pager(totalRows);
    String currentPage = request.getParameter( "currentPage");
     if (currentPage != null) {
      pager.refresh(Integer.parseInt(currentPage));
    }
    String pagerMethod = request.getParameter( "pagerMethod");
     if (pagerMethod != null) {
       if (pagerMethod.equals( "first")) {
        pager.first();
      } else if (pagerMethod.equals( "previous")) {
        pager.previous();
      } else if (pagerMethod.equals( "next")) {
        pager.next();
      } else if (pagerMethod.equals( "last")) {
        pager.last();
      }
    }
     return pager;
  }

}

3. UserDAO:

public Collection findWithPage( final Pager pager){
          
           return this.getHibernateTemplate().executeFind( new HibernateCallback(){
             public Object doInHibernate(Session session) throws HibernateException,SQLException{
              Query query = session.createQuery( "from User");
              query.setFirstResult(pager.getStartRow());
              query.setMaxResults(pager.getPageSize());
               return query.list();
            }
          });
        }

4.UserAction:

public ActionForward show(ActionMapping mapping, ActionForm form,
      HttpServletRequest request, HttpServletResponse response) {

    Collection clUsers = null;
    List list = userService.findAll();
     int totalRows = list.size();
    Pager pager = PagerHelper.getPager(request,totalRows);
    clUsers = userService.findWithPage(pager);
    request.setAttribute( "clUsers", clUsers);
    request.setAttribute( "pager", pager);

     return mapping.findForward( "success");

  }

5.UserInfo.jsp:

----------
  "pager" name= "pager">

"/user.do?methodCode=show&pagerMethod=first">首页
    "/user.do?methodCode=show&pagerMethod=previous"
      paramId= "currentPage" paramName= "pager" paramProperty= "currentPage">上一页
    "/user.do?methodCode=show&pagerMethod=next"
      paramId= "currentPage" paramName= "pager" paramProperty= "currentPage">下一页
    "/user.do?methodCode=show&pagerMethod=last"
      paramId= "currentPage" paramName= "pager" paramProperty= "currentPage">尾页
    第"pager" property= "currentPage" />页
    共"pager" property= "totalPages" />页

注：其中的paramId，paramName，paramProperty没起作用！！！