多关联分页查询 - 陀螺ING

一、实体类

*
 * 一级分类的实体类对象
 */
public class Category implements Serializable {
    private Integer cid;
    private String cname;
    //一级分类中存放二级分类的集合
    private Set<CategorySecond> categorySeconds=new HashSet<CategorySecond>();
    
    //get、set
}

/*
 * 二级分类实体
 */
public class CategorySecond {

    private Integer csid;
    private String csname;
    //所属一级分类,存的是一级分类的对象
    private Category category;
    //配置商品集合
    private Set<Product> products=new HashSet<Product>();

    //get、set
}

二、映射文件

1、一级分类

<hibernate-mapping>
    <class name="cn.itcast.shop.category.vo.Category" table="category">
        <id name="cid">
            <generator class="native"/>
        </id>
        <property name="cname"/>
        
        <!-- 配置二级分类的集合 order-by是按顺序排列 -->
        <set order-by="csid" name="categorySeconds" lazy="false">
            <key column="cid"/>
            <one-to-many class="cn.itcast.shop.categorysecond.vo.CategorySecond"/>
        </set>
    </class>
</hibernate-mapping>

2、二级分类

<hibernate-mapping>
    <class name="cn.itcast.shop.categorysecond.vo.CategorySecond" table="categorysecond">
        <id name="csid">
            <generator class="native"/>
        </id>
        <property name="csname"/>
        <!-- 二级分类与一级分类的关联   lazy为延迟加载 -->
        <many-to-one name="category" lazy="false" class="cn.itcast.shop.category.vo.Category" column="cid"></many-to-one>
        
        <!-- 二级分类与商品的关联 -->
        <set name="products">
            <key column="csid"/>
            <one-to-many class="cn.itcast.shop.product.vo.Product"/>
        </set>
    </class>
</hibernate-mapping>

三、action

/*
 * 商品的Action对象
 */
public class ProductAction extends ActionSupport implements ModelDriven<Product> {
    //用于接收数据的模型驱动
    private Product product=new Product();
    public Product getModel() {
        return product;
    }
    
    //注入商品的Service的方法
    private ProductService productService;
    public void setProductService(ProductService productService) {
        this.productService = productService;
    }
    
    //接收分类cid
    private Integer cid;
    //接收二级分类的id
    private Integer csid;
    //注入一级分类的Service
    private CategoryService categoryService;
    //接收当前的页数
    private int page;
    
    
    //根据分类的id查询商品
    public String findByCid(){ 
        //List<Category> cList=categoryService.findAll();
        PageBean<Product> pageBean=productService.findByPageCid(cid,page);//根据一级分类查询商品,分页查询
        //将PageBean存入到值栈中
        ActionContext.getContext().getValueStack().set("pageBean", pageBean);
        return "findByCid";
    }
     
    //根据二级分类的ID查询商品
    public String findByCsid(){
        
        //根据二级分类查询商品
        PageBean<Product> pageBean=productService.findByPageCsid(csid,page);
        //将PageBean存入到值栈中
        ActionContext.getContext().getValueStack().set("pageBean", pageBean);
        return "findByCsid";
        
    }
}

四、分页查询类

分页类的封装
package cn.itcast.shop.utils;

import java.util.List;

/*
 * 分页类的封装
 */
public class PageBean<T> {
    private int page;//当前页数
    private int totalCount;//总记录数
    private int totalPage;//总页数
    private int limit;//每页显示的记录数
    private List<T> list;//每页显示数据的集合
    public int getPage() {
        return page;
    }
    public void setPage(int page) {
        this.page = page;
    }
    public int getTotalCount() {
        return totalCount;
    }
    public void setTotalCount(int totalCount) {
        this.totalCount = totalCount;
    }
    public int getTotalPage() {
        return totalPage;
    }
    public void setTotalPage(int totalPage) {
        this.totalPage = totalPage;
    }
    public int getLimit() {
        return limit;
    }
    public void setLimit(int limit) {
        this.limit = limit;
    }
    public List<T> getList() {
        return list;
    }
    public void setList(List<T> list) {
        this.list = list;
    }
    

}

五、Service

package cn.itcast.shop.product.service;

import java.util.List;

import org.springframework.transaction.annotation.Transactional;

import cn.itcast.shop.product.dao.ProductDao;
import cn.itcast.shop.product.vo.Product;
import cn.itcast.shop.utils.PageBean;
/*
 * 商品的业务层代码
 */
@Transactional
public class ProductService {
    //注入ProductDao
    private ProductDao productDao;

    public void setProductDao(ProductDao productDao) {
        this.productDao = productDao;
    }

    //首页上热门商品查询
    public List<Product> findHot() {
        return productDao.findHot();
    }

    //首页上最新商品的查询
    public List<Product> findNew() {
        return productDao.findNew();
    }

    //根据商品的ID查询商品
    public Product findByPid(Integer pid) {
        return productDao.findByPid(pid);
    }

    //根据一级分类的cid带有分页查询商品
    public PageBean<Product> findByPageCid(Integer cid, int page) {
        PageBean<Product> pageBean=new PageBean<Product>();
        //设置当前页数
        pageBean.setPage(page);
        //设置每页显示记录数
        int limit=8;
        pageBean.setLimit(limit);
        //设置总记录数
        int totalCount=0;
        totalCount=productDao.findCountCid(cid);
        pageBean.setTotalCount(totalCount);
        //设置总页数
        int totalPage=0;
        //Math.ceil(totalCount / limit);
        if(totalCount % limit==0){
            totalPage=totalCount/limit;
        }else{
            totalPage=totalCount/limit + 1;
        }
        pageBean.setTotalPage(totalPage);
        //每页显示的数据集合
        //从哪开始
        int begin=(page-1)*limit;
        List<Product> list=productDao.findByPageCid(cid,begin,limit);
        pageBean.setList(list);
        return pageBean;
    }

    //根据二级分类查寻商品信息
    public PageBean<Product> findByPageCsid(Integer csid, int page) {
        PageBean<Product> pageBean=new PageBean<Product>();
        //设置当前页数
        pageBean.setPage(page);
        //设置每页显示记录数
        int limit=8;
        pageBean.setLimit(limit);
        //设置总记录数
        int totalCount=0;
        totalCount=productDao.findCountCsid(csid);
        pageBean.setTotalCount(totalCount);
        //设置总页数
        int totalPage=0;
        //Math.ceil(totalCount / limit);
        if(totalCount % limit==0){
            totalPage=totalCount/limit;
        }else{
            totalPage=totalCount/limit + 1;
        }
        pageBean.setTotalPage(totalPage);
        //每页显示的数据集合
        //从哪开始
        int begin=(page-1)*limit;
        List<Product> list=productDao.findByPageCsid(csid,begin,limit);
        pageBean.setList(list);
        return pageBean;

    }

}

六、DAO

package cn.itcast.shop.product.dao;

import java.util.List;

import org.hibernate.criterion.DetachedCriteria;
import org.hibernate.criterion.Order;
import org.hibernate.criterion.Restrictions;
import org.springframework.orm.hibernate3.support.HibernateDaoSupport;

import cn.itcast.shop.product.vo.Product;
import cn.itcast.shop.utils.PageHibernateCallback;

/*
 * 商品的持久层代码
 */
public class ProductDao extends HibernateDaoSupport{

    //根据分类id查询商品的个数
    public int findCountCid(Integer cid) {
        String hql="select count(*) from Product p where p.categorySecond.category.cid=?";
        List<Long> list=this.getHibernateTemplate().find(hql,cid);
        if(list != null && list.size()>0){
            return list.get(0).intValue();
        }
        return 0;
    }

    //根据分类id查询商品的集合
    public List<Product> findByPageCid(Integer cid, int begin, int limit) {
        String hql="select p from Product p join p.categorySecond cs join cs.category c where c.cid=?";
        //分页另一种写法
        List<Product> list=this.getHibernateTemplate().execute(new PageHibernateCallback<Product>(hql,new Object[]{cid},begin,limit));
        if(list != null && list.size()>0){
            return list;
        }
        return null;
    }

    //根据二级分类查询商品个数
    public int findCountCsid(Integer csid) {
        String hql="select count(*) from Product p where p.categorySecond.csid=?";
        List<Long> list=this.getHibernateTemplate().find(hql, csid);
        if(list != null && list.size()>0){
            return list.get(0).intValue();
        }
        return 0;
    }

    //根据二级分类查询商品信息
    public List<Product> findByPageCsid(Integer csid, int begin, int limit) {

        String hql="select p from Product p join p.categorySecond cs where cs.csid=?";
        List<Product> list=this.getHibernateTemplate().execute(new PageHibernateCallback<Product>(hql,new Object[]{csid},begin,limit));
        if(list != null && list.size()>0){
            return list;
        }
        return null;
    }

}

七、JSP

<div class="pagination">
            <span>第 <s:property value="pageBean.page"/>/<s:property value="pageBean.totalPage"/> 页</span>
        <s:if test="cid != null">
            <s:if test="pageBean.page != 1">
                <a href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=1" class="firstPage">&nbsp;</a>
                <a href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="pageBean.page-1"/>" class="previousPage">&nbsp;</a>
            </s:if>
            
            <s:iterator var="i" begin="1" end="pageBean.totalPage">
                <s:if test="pageBean.page != #i">
                    <a href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="#i"/>"><s:property value="#i"/></a>
                </s:if>
                <s:else>
                    <span class="currentPage"><s:property value="#i"/></span>
                </s:else>
            </s:iterator>
            
            <s:if test="pageBean.page != pageBean.totalPage">    
                <a class="nextPage" href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="pageBean.page+1"/>">&nbsp;</a>
                <a class="lastPage" href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="pageBean.totalPage"/>">&nbsp;</a>
            </s:if>
        </s:if>    
        <s:if test="csid != null">
            <s:if test="pageBean.page != 1">
                <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=1" class="firstPage">&nbsp;</a>
                <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="pageBean.page-1"/>" class="previousPage">&nbsp;</a>
            </s:if>
            
            <s:iterator var="i" begin="1" end="pageBean.totalPage">
                <s:if test="pageBean.page != #i">
                    <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="#i"/>"><s:property value="#i"/></a>
                </s:if>
                <s:else>
                    <span class="currentPage"><s:property value="#i"/></span>
                </s:else>
            </s:iterator>
            
            <s:if test="pageBean.page != pageBean.totalPage">    
                <a class="nextPage" href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="pageBean.page+1"/>">&nbsp;</a>
                <a class="lastPage" href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="pageBean.totalPage"/>">&nbsp;</a>
            </s:if>
        </s:if>    
    </div>

posted on 2016-07-22 15:55 陀螺ING 阅读(1250) 评论(0) 收藏举报

刷新页面返回顶部

郭贤达的博客

公告