SSH分页

先是一个page的bean：

package com.leatherstore.other; 

public class Page { 

    /** 是否有上一页 */ 
    private boolean hasPrePage; 
    
    /** 是否有下一页 */ 
    private boolean hasNextPage; 
        
    /** 每页的数量 */ 
    private int everyPage; 
    
    /** 总页数 */ 
    private int totalPage; 
        
    /** 当前页*/ 
    private int currentPage; 
    
    /** 起始点 */ 
    private int beginIndex; 
    
    /** 总记录数*/ 
    private int totalCount; 
    
    /** 
* @return totalCount 
*/ 
public int getTotalCount() { 
return totalCount; 
} 

/** 
* @param totalCount 要设置的 totalCount 
*/ 
public void setTotalCount(int totalCount) { 
this.totalCount = totalCount; 
} 

/** The default constructor */ 
    public Page(){ 
        
    } 
    
    /** construct the page by everyPage 
     * @param everyPage 
     * */ 
    public Page(int everyPage){ 
        this.everyPage = everyPage; 
    } 
    
    /** The whole constructor */ 
    public Page(boolean hasPrePage, boolean hasNextPage,  
                    int everyPage, int totalPage, 
                    int currentPage, int beginIndex,int totalCount) { 
        this.hasPrePage = hasPrePage; 
        this.hasNextPage = hasNextPage; 
        this.everyPage = everyPage; 
        this.totalPage = totalPage; 
        this.currentPage = currentPage; 
        this.beginIndex = beginIndex; 
        this.totalCount = totalCount; 
    } 

    /** 
     * @return 
     * Returns the beginIndex. 
     */ 
    public int getBeginIndex() { 
        return beginIndex; 
    } 
    
    /** 
     * @param beginIndex 
     * The beginIndex to set. 
     */ 
    public void setBeginIndex(int beginIndex) { 
        this.beginIndex = beginIndex; 
    } 
    
    /** 
     * @return 
     * Returns the currentPage. 
     */ 
    public int getCurrentPage() { 
        return currentPage; 
    } 
    
    /** 
     * @param currentPage 
     * The currentPage to set. 
     */ 
    public void setCurrentPage(int currentPage) { 
        this.currentPage = currentPage; 
    } 
    
    /** 
     * @return 
     * Returns the everyPage. 
     */ 
    public int getEveryPage() { 
        return everyPage; 
    } 
    
    /** 
     * @param everyPage 
     * The everyPage to set. 
     */ 
    public void setEveryPage(int everyPage) { 
        this.everyPage = everyPage; 
    } 
    
    /** 
     * @return 
     * Returns the hasNextPage. 
     */ 
    public boolean getHasNextPage() { 
        return hasNextPage; 
    } 
    
    /** 
     * @param hasNextPage 
     * The hasNextPage to set. 
     */ 
    public void setHasNextPage(boolean hasNextPage) { 
        this.hasNextPage = hasNextPage; 
    } 
    
    /** 
     * @return 
     * Returns the hasPrePage. 
     */ 
    public boolean getHasPrePage() { 
        return hasPrePage; 
    } 
    
    /** 
     * @param hasPrePage 
     * The hasPrePage to set. 
     */ 
    public void setHasPrePage(boolean hasPrePage) { 
        this.hasPrePage = hasPrePage; 
    } 
    
    /** 
     * @return Returns the totalPage. 
     * 
     */ 
    public int getTotalPage() { 
        return totalPage; 
    } 
    
    /** 
     * @param totalPage 
     * The totalPage to set. 
     */ 
    public void setTotalPage(int totalPage) { 
        this.totalPage = totalPage; 
    } 
} 

然后构建一个page的工厂PageUtil：

public class PageUtil { 
/** 
* Use the origin page to create a new page 
* 
* @param page 
* @param totalRecords 
* @return 
*/ 
public static Page createPage(Page page, int totalRecords) { 
return createPage(page.getEveryPage(), page.getCurrentPage(), 
totalRecords); 
} 

/** 
* the basic page utils not including exception handler 
* 
* @param everyPage 
* @param currentPage 
* @param totalRecords 
* @return page 
*/ 
public static Page createPage(int everyPage, int currentPage, 
int totalRecords) { 
everyPage = getEveryPage(everyPage); 
currentPage = getCurrentPage(currentPage); 
int beginIndex = getBeginIndex(everyPage, currentPage); 
int totalPage = getTotalPage(everyPage, totalRecords); 
boolean hasNextPage = hasNextPage(currentPage, totalPage); 
boolean hasPrePage = hasPrePage(currentPage); 

return new Page(hasPrePage, hasNextPage, everyPage, totalPage, 
currentPage, beginIndex, totalRecords); 
} 

private static int getEveryPage(int everyPage) { 
return everyPage == 0 ? 10 : everyPage; 
} 

private static int getCurrentPage(int currentPage) { 
return currentPage == 0 ? 1 : currentPage; 
} 

private static int getBeginIndex(int everyPage, int currentPage) { 
return (currentPage - 1) * everyPage; 
} 

private static int getTotalPage(int everyPage, int totalRecords) { 
int totalPage = 0; 

if (totalRecords % everyPage == 0) 
totalPage = totalRecords / everyPage; 
else 
totalPage = totalRecords / everyPage + 1; 

return totalPage; 
} 

private static boolean hasPrePage(int currentPage) { 
return currentPage == 1 ? false : true; 
} 

private static boolean hasNextPage(int currentPage, int totalPage) { 
return currentPage == totalPage || totalPage == 0 ? false : true; 
} 

}

然后建一个专用的bean：

package com.leatherstore.hibernate.domain; 

import java.util.List; 

import com.leatherstore.other.Page; 

public class Result { 
private Page page;  //分页信息 
private List content;  //每页显示的集合 
/** 
     * The default constructor 
     */ 
    public Result() { 
        super(); 
    } 

    /** 
     * The constructor using fields 
     * 
     * @param page 
     * @param content 
     */ 
    public Result(Page page, List content) { 
        this.page = page; 
        this.content = content; 
    } 

    /** 
     * @return Returns the content. 
     */ 
    public List getContent() { 
        return content; 
    } 

    /** 
     * @return Returns the page. 
     */ 
    public Page getPage() { 
        return page; 
    } 

    /** 
     * @param content 
     *            The content to set. 
     */ 
    public void setContent(List content) { 
        this.content = content; 
    } 

    /** 
     * @param page 
     *            The page to set. 
     */ 
    public void setPage(Page page) { 
        this.page = page; 
    } 
} 

然后在数据访问层写两个方法：
ProductDAO：

public List getProductByPage(Page page);  
public int getProductCount();  //返回数据的总数 

ProductDAO的接口实现ProductDAOImpl：

//为了在spring里统一编程风格：我用的回调的方法 
public List getProductByPage(final Page page) { 
return this.getHibernateTemplate().executeFind(new HibernateCallback(){ 
public Object doInHibernate(Session session) throws HibernateException, SQLException { 
Query query=session.createQuery("from Productinfo"); 
query.setFirstResult(page.getBeginIndex()); //hibernate分页的精髓   呵呵 
    query.setMaxResults(page.getEveryPage()); 
    return query.list(); 
} 
}); 
} 

public int getProductCount() { 
List list=this.getHibernateTemplate().find("select count(*) from Productinfo"); 
return ((Integer)list.iterator().next()).intValue(); 
} 

然后是业务层IProduct：

public Result listProduct(Page page);

然后IProduct接口的实现：IProductImpl：

private ProductDAO productDAO; 
public void setProductDAO(ProductDAO productDAO){ 
this.productDAO=productDAO; 
} 

public Result listProduct(Page page) { 
int totalRecords = this.productDAO.getProductCount(); 
page = PageUtil.createPage(page, totalRecords); 
        List products = this.productDAO.getProductByPage(page);      
        return new Result(page, products); 
} 

Action

Page page = new Page();   //实例化一个page对象 
page.setEveryPage(10);    //设置每页显示的条数 
page.setCurrentPage(1);    //为第一页 
Result result = pdp.productlist(page); 
request.setAttribute("page", pageinfo); 
request.setAttribute("productlist", list); 
return mapping.findForward("showProduct"); 

JSP

<logic:iterate id="product" name="productlist"> 
//中间迭代所要显示的数据 
</logic:iterate> 
<tr> 
    <td width="80" height="30">&nbsp;</td> 
    <logic:equal value="true" name="page" property="hasPrePage"> 
    <td width="150" height="30"><div align="right"><a href="../product.do?method=showProductByTag&index=first&msg=${msg }">首页</a></div></td> 
    <td width="80" height="30"><div align="center"><a href="../product.do?method=showProductByTag&index=prew&pageno=${page.currentPage -1}&msg=${msg }">上一页</a></div></td> 
    </logic:equal> 
    <logic:notEqual value="true" name="page" property="hasPrePage"> 
    <td width="150" height="30"><div align="right">首页</div></td> 
    <td width="80" height="30"><div align="center">上一页</div></td> 
    </logic:notEqual> 
    <logic:equal value="true" name="page" property="hasNextPage"> 
    <td width="80" height="30"><div align="center"><a href="../product.do?method=showProductByTag&index=next&pageno=${page.currentPage +1 }&msg=${msg }">下一页</a></div></td> 
    <td width="80" height="30"><div align="center"><a href="../product.do?method=showProductByTag&index=end&pageno=${page.totalPage }&msg=${msg }">尾页</a></div></td> 
    </logic:equal> 
    <logic:notEqual value="true" name="page" property="hasNextPage"> 
    <td width="80" height="30"><div align="center">下一页</div></td> 
    <td width="80" height="30"><div align="center">尾页</div></td> 
    </logic:notEqual> 
    <td height="30" colspan="3"><div align="center">页次${page.currentPage }/${page.totalPage }&nbsp;&nbsp;&nbsp;共${page.totalCount }条记录</div>      <div align="center"></div></td> 
  </tr> 

然后productAction里面的showProductByTag代码如下：

Page page = new Page(); 
page.setEveryPage(10); 
String pagemark = request.getParameter("goto"); 
if (pagemark == null) { 
String state = request.getParameter("index"); 
String pageno = request.getParameter("pageno"); 
System.out.println("pageno=" + pageno); 
if ("first".equals(state)) { 
page.setCurrentPage(1); 
Result result = pdp.productlist(page); 
request.setAttribute("page", result.getPage()); 
request.setAttribute("productlist", result.getContent()); 
} else if ("prew".equals(state)) { 
page.setCurrentPage(Integer.parseInt(pageno)); 
Result result = pdp.productlist(page); 
request.setAttribute("page", result.getPage()); 
request.setAttribute("productlist", result.getContent()); 
} else if ("next".equals(state)) { 
page.setCurrentPage(Integer.parseInt(pageno)); 
Result result = pdp.productlist(page); 
request.setAttribute("page", result.getPage()); 
request.setAttribute("productlist", result.getContent()); 
} else if ("end".equals(state)) { 
page.setCurrentPage(Integer.parseInt(pageno)); 
Result result = pdp.productlist(page); 
request.setAttribute("page", result.getPage()); 
request.setAttribute("productlist", result.getContent()); 
} 
} else { 
page.setCurrentPage(Integer.parseInt(pagemark)); 
Result result = pdp.productlist(page); 
request.setAttribute("page", result.getPage()); 
request.setAttribute("productlist", result.getContent()); 
} 
return mapping.findForward("showProduct");