分页查询用到工具类

我用的是SSH框架，但主要用到的分页逻辑应该是大同小异的；

首先定义工具类;

package com.util;

import java.util.List;



public class pageBean<E> {
    private List<E> list;  //要返回的某一页的记录列表    
    private int allRow; //总记录数    
    private int totalPage;  //总页数    
    private int currentPage;  //当前页    
    private int pageSize;  //每页的记录数    
    private boolean isFirstPage;  //是否为当前第一页    
    private boolean isLastPage;  //是否为最后一页    
    private boolean hasPreviousPage;  //是否有前一页    
    private boolean hasNextPage;  //是否有下一页
    
    /**   
     * 初始化分页信息   
     */    
    public void init(){    
    this.isFirstPage = isFirstPage;    
    this.isLastPage = isLastPage;    
    this.hasPreviousPage = hasPreviousPage;    
    this.hasNextPage = hasNextPage;    
    }    
    /**   
     * 计算总页数  静态方法   
     * @param pageSize  每页的记录数   
     * @param allRow  总记录数   
     * @return 总页数   
     */    
    public static int countTatalPage(final int pageSize,final int allRow){    
    int toalPage = allRow % pageSize == 0 ? allRow/pageSize : allRow/pageSize + 1;    
    return toalPage;    
    }    
    /**   
     * 计算当前页开始的记录   
     * @param pageSize 每页记录数   
     * @param currentPage 当前第几页   
     * @return 当前页开始记录号   
     */    
    public static int countOffset(final int pageSize,final int currentPage){    
    final int offset = pageSize * (currentPage - 1);    
    return offset;    
    }    
    /**   
     * 计算当前页，若为0或者请求的URL中没有“?page = ”则用1代替   
     * @param page 传入的参数（可能为空，即0  则返回1）   
     * @return   
     */    
    public static int countCurrentPage(int page){    
    final int curpage = (page == 0 ? 1 : page);    
    return curpage;    
    }   
    

    public List<E> getList() {
        return list;
    }
    public void setList(List<E> list) {
        this.list = list;
    }
    public int getAllRow() {
        return allRow;
    }
    public void setAllRow(int allRow) {
        this.allRow = allRow;
    }
    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;
    }
    public int getPageSize() {
        return pageSize;
    }
    public void setPageSize(int pageSize) {
        this.pageSize = pageSize;
    }
    public boolean isFirstPage() {
        return isFirstPage;
    }
    public void setFirstPage(boolean isFirstPage) {
        this.isFirstPage = isFirstPage;
    }
    public boolean isLastPage() {
        return isLastPage;
    }
    public void setLastPage(boolean isLastPage) {
        this.isLastPage = isLastPage;
    }
    public boolean isHasPreviousPage() {
        return hasPreviousPage;
    }
    public void setHasPreviousPage(boolean hasPreviousPage) {
        this.hasPreviousPage = hasPreviousPage;
    }
    public boolean isHasNextPage() {
        return hasNextPage;
    }
    public void setHasNextPage(boolean hasNextPage) {
        this.hasNextPage = hasNextPage;
    }
    
}

然后要做的就是在action中查询一个结果集；并调用这个工具类，把结果集放进去；

    public pageBean<TDoc> queryForPage(String hql,int pageSize, int page) {   
    //final String hql = "from TZhaopin where del='no' order by fabushijian desc"; //查询语句    
    int allRow = memberDao.getAllRowCount(hql);  //总记录数    
    int totalPage = pageBean.countTatalPage(pageSize, allRow); //总页数    
    final int offset = pageBean.countOffset(pageSize, page); //当前页开始记录    
    final int length = pageSize; // 每页记录数    
    final int currentPage = pageBean.countCurrentPage(page); // 当前页    
    List list = memberDao.queryForPage(hql, offset, length); //    
    //把分页信息保存到Bean当中    
    pageBean<TDoc> pageBean  = new pageBean<TDoc>();    
    pageBean.setPageSize(pageSize);    
    pageBean.setCurrentPage(currentPage);    
    pageBean.setAllRow(allRow);    
    pageBean.setTotalPage(totalPage);    
    pageBean.setList(list);    
    pageBean.init();    
    return pageBean;    
    } 

然后就是把数据放到前台页面上就ok了；

<div id="box2" style="float: right;">
                    <s:iterator value="pageBean">    
                            <tr>    
                         <td colspan="6" align="center" bgcolor="#5BA8DE">    
                                
        
                         <s:if test="%{currentPage == 1}">    
                           首 页  上一页    
                         </s:if>    
                         <!-- currentPage为当前页 -->    
                         <s:else>    
                           <a href="index.action?page=1">首 页</a>    
                           <a href="index.action?page=<s:property value="%{currentPage-1}"/>">上一页</a>    
                         </s:else>    
        
                         <s:if test="%{currentPage != totalPage}">    
                        <a href="index.action?page=<s:property value="%{currentPage+1}"/>">下一页</a>    
                         <a href="index.action?page=<s:property value="totalPage"/>">尾 页</a>    
                         </s:if>    
        
                         <s:else>    
                         下一页 尾 页     
                         </s:else>
                              <br/>
                              <!-- 共<s:property value="allRow"/>条记录   -->
                             共<s:property value="totalPage"/>页         &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp;
                             当前第<s:property value="currentPage"/>&nbsp;页    &nbsp;
                         </td>    
                            </tr>    
                        </s:iterator> 
                </div>

效果如下：