分頁查詢用到工具類

我用的是SSH框架，但主要用到的分頁邏輯應該是大同小異的；

首先定義工具類;

package com.util;

import java.util.List;



public class pageBean<E> {
    private List<E> list;  //要返回的某一頁的記錄列表    
    private int allRow; //總記錄數    
    private int totalPage;  //總頁數    
    private int currentPage;  //當前頁    
    private int pageSize;  //每頁的記錄數    
    private boolean isFirstPage;  //是否為當前第一頁    
    private boolean isLastPage;  //是否為最后一頁    
    private boolean hasPreviousPage;  //是否有前一頁    
    private boolean hasNextPage;  //是否有下一頁
    
    /**   
     * 初始化分頁信息   
     */    
    public void init(){    
    this.isFirstPage = isFirstPage;    
    this.isLastPage = isLastPage;    
    this.hasPreviousPage = hasPreviousPage;    
    this.hasNextPage = hasNextPage;    
    }    
    /**   
     * 計算總頁數  靜態方法   
     * @param pageSize  每頁的記錄數   
     * @param allRow  總記錄數   
     * @return 總頁數   
     */    
    public static int countTatalPage(final int pageSize,final int allRow){    
    int toalPage = allRow % pageSize == 0 ? allRow/pageSize : allRow/pageSize + 1;    
    return toalPage;    
    }    
    /**   
     * 計算當前頁開始的記錄   
     * @param pageSize 每頁記錄數   
     * @param currentPage 當前第幾頁   
     * @return 當前頁開始記錄號   
     */    
    public static int countOffset(final int pageSize,final int currentPage){    
    final int offset = pageSize * (currentPage - 1);    
    return offset;    
    }    
    /**   
     * 計算當前頁，若為0或者請求的URL中沒有“?page = ”則用1代替   
     * @param page 傳入的參數（可能為空，即0  則返回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中查詢一個結果集；並調用這個工具類，把結果集放進去；

    public pageBean<TDoc> queryForPage(String hql,int pageSize, int page) {   
    //final String hql = "from TZhaopin where del='no' order by fabushijian desc"; //查詢語句    
    int allRow = memberDao.getAllRowCount(hql);  //總記錄數    
    int totalPage = pageBean.countTatalPage(pageSize, allRow); //總頁數    
    final int offset = pageBean.countOffset(pageSize, page); //當前頁開始記錄    
    final int length = pageSize; // 每頁記錄數    
    final int currentPage = pageBean.countCurrentPage(page); // 當前頁    
    List list = memberDao.queryForPage(hql, offset, length); //    
    //把分頁信息保存到Bean當中    
    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;    
    } 

然后就是把數據放到前台頁面上就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 頁  上一頁    
                         </s:if>    
                         <!-- currentPage為當前頁 -->    
                         <s:else>    
                           <a href="index.action?page=1">首 頁</a>    
                           <a href="index.action?page=<s:property value="%{currentPage-1}"/>">上一頁</a>    
                         </s:else>    
        
                         <s:if test="%{currentPage != totalPage}">    
                        <a href="index.action?page=<s:property value="%{currentPage+1}"/>">下一頁</a>    
                         <a href="index.action?page=<s:property value="totalPage"/>">尾 頁</a>    
                         </s:if>    
        
                         <s:else>    
                         下一頁 尾 頁     
                         </s:else>
                              <br/>
                              <!-- 共<s:property value="allRow"/>條記錄   -->
                             共<s:property value="totalPage"/>頁         &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp;
                             當前第<s:property value="currentPage"/>&nbsp;頁    &nbsp;
                         </td>    
                            </tr>    
                        </s:iterator> 
                </div>

效果如下：