现在我们要实现下面的需求：
当用户点击左侧二级菜单选项的时候，在右侧要显示对应的该二级菜单项下面存在哪些商品，例如点击潮流女装，要在右侧分页显示该潮流女装下对应哪些商品
1、要分页显示 首先要获得该二级菜单下对应商品的总数
2、分页查询和显示该二级菜单下对应商品的数目
我们首先在productList.jsp
<s:iterator var="cs" value="#c.categorySeconds"> <dd> <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="#cs.csid"/>&page=1"><s:property value="#cs.csname"/></a> </dd> </s:iterator>
此处就是表示当前用户点击了某个二级菜单选项 需要传递当前二级菜单的csid和当前默认的page
传递到product_findByCsid.action传递到ProductAction的findByCsid这个方法中进行处理，ProductAction中需要定义一个成员变量csid接受传递过来的二级菜单选项的id值，也需要定义一个成员变量page接受page的值
我们来看对应的代码
package cn.itcast.shop.product.action; import java.util.List; import org.apache.struts2.ServletActionContext; import cn.itcast.shop.category.beans.Category; import cn.itcast.shop.category.service.CategoryService; import cn.itcast.shop.product.beans.Product; import cn.itcast.shop.product.service.ProductService; import cn.itcast.shop.utils.PageBean; import com.opensymphony.xwork2.ActionContext; import com.opensymphony.xwork2.ActionSupport; import com.opensymphony.xwork2.ModelDriven; public class ProductAction extends ActionSupport implements ModelDriven<Product>{ private ProductService productService; private CategoryService categoryService; // 接收分类cid private Integer cid; // 接收当前页数: private int page; // 接收二级分类id private Integer csid; public Integer getCsid() { return csid; } public void setCsid(Integer csid) { this.csid = csid; } public int getPage() { return page; } public void setPage(int page) { this.page = page; } public Integer getCid() { return cid; } public void setCid(Integer cid) { this.cid = cid; } public CategoryService getCategoryService() { return categoryService; } public void setCategoryService(CategoryService categoryService) { this.categoryService = categoryService; } public ProductService getProductService() { return productService; } public void setProductService(ProductService productService) { this.productService = productService; } public Product getProduct() { return product; } public void setProduct(Product product) { this.product = product; } private Product product = new Product(); @Override public Product getModel() { // TODO Auto-generated method stub return product; } // 根据商品的ID进行查询商品:执行方法: public String findByPid() throws Exception{ // 调用Service的方法完成查询. product = productService.findByPid(product.getPid()); return "findByPid"; } // 根据分类的id查询商品: public String findByCid() { List<Category> cList = categoryService.findAll(); ActionContext.getContext().getValueStack().set("cList", cList); PageBean<Product> pageBean = productService.findByPageCid(cid, page);// 根据一级分类查询商品,带分页查询 // 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"; } }
我们来看看对应的业务类方法
package cn.itcast.shop.product.service; import java.util.List; import cn.itcast.shop.product.beans.Product; import cn.itcast.shop.product.dao.ProductDao; import cn.itcast.shop.utils.PageBean; public class ProductService { private ProductDao productDao; public ProductDao getProductDao() { return productDao; } public void setProductDao(ProductDao productDao) { this.productDao = productDao; } public List<Product> findHot() { // TODO Auto-generated method stub return productDao.findHot(); } public List<Product> findNew(){ return productDao.findNew(); } 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; } // 根据二级分类查询商品信息 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; } }
我们来看看对应的dao数据库层的方法
package cn.itcast.shop.product.dao; import java.util.List; import org.springframework.orm.hibernate3.support.HibernateDaoSupport; import cn.itcast.shop.product.beans.Product; import cn.itcast.shop.utils.PageHibernateCallback; import java.sql.SQLException; import java.util.List; import org.hibernate.HibernateException; import org.hibernate.Session; import org.hibernate.criterion.DetachedCriteria; import org.hibernate.criterion.Order; import org.hibernate.criterion.Restrictions; import org.springframework.orm.hibernate3.HibernateCallback; import org.springframework.orm.hibernate3.support.HibernateDaoSupport; public class ProductDao extends HibernateDaoSupport { // 首页上热门商品查询 public List<Product> findHot() { // 使用离线条件查询. DetachedCriteria criteria = DetachedCriteria.forClass(Product.class); // 查询热门的商品,条件就是is_host = 1 criteria.add(Restrictions.eq("is_hot", 1)); // 倒序排序输出: criteria.addOrder(Order.desc("pdate")); // 执行查询: List<Product> list = this.getHibernateTemplate().findByCriteria( criteria, 0, 10); return list; } // 首页上最新商品的查询 public List<Product> findNew() { // 使用离线条件查询: DetachedCriteria criteria = DetachedCriteria.forClass(Product.class); // 按日期进行倒序排序: criteria.addOrder(Order.desc("pdate")); // 执行查询: List<Product> list = this.getHibernateTemplate().findByCriteria(criteria, 0, 10); return list; } // 根据商品ID查询商品 public Product findByPid(Integer pid) { return (Product) this.getHibernateTemplate().get(Product.class, pid); } //获得对应的一级分类下的所有的商品总的记录数 public int findCountCid(Integer cid) { // TODO Auto-generated method stub 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) { // select p.* from category c,categorysecond cs,product p where c.cid = cs.cid and cs.csid = p.csid and c.cid = 2 // select p from Category c,CategorySecond cs,Product p where c.cid = cs.category.cid and cs.csid = p.categorySecond.csid and c.cid = ? 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 = (List<Product>) 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 = (List<Product>) this.getHibernateTemplate().execute(new PageHibernateCallback<Product>(hql, new Object[]{csid}, begin, limit)); if(list != null && list.size() > 0){ return list; } return null; } }
在
// 根据二级分类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"; }
我们将查询的二级菜单选项下的商品集合、当前的page等封装到了一个PageBean对象中存储在值栈中
<!-- 商品模块的Action --> <action name="product_*" class="productAction" method="{1}"> <result name="findByPid">/WEB-INF/jsp/product.jsp</result> <result name="findByCid">/WEB-INF/jsp/productList.jsp</result> <result name="findByCsid">/WEB-INF/jsp/productList.jsp</result> </action> </package>
这里我们是跳转到
productList.jsp
这里既可以显示一级分类下的商品，也可以显示二级分类下的商品，所以在
productList.jsp需要判断当前是显示那种情况
<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"> </a> <a href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="pageBean.page-1"/>" class="previousPage"> </a> </s:if> <s:iterator var="i" begin="1" end="pageBean.totalPage"> <s:if test="pageBean.page != #i"> <a href="${ 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="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="pageBean.page+1"/>"> </a> <a class="lastPage" href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="pageBean.totalPage"/>"> </a> </s:if> </s:if> <s:if test="csid != null"> <s:if test="pageBean.page != 1"> <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=1" class="firstPage"> </a> <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="pageBean.page-1"/>" class="previousPage"> </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"/>"> </a> <a class="lastPage" href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="pageBean.totalPage"/>"> </a> </s:if> </s:if>
<s:if test="cid != null">表示就是当前一级分类的cid不等于null，就显示一级分类下的商品进行分页显示
整个
productList.jsp的代码如下所示：
<%@ page language="java" contentType="text/html; charset=UTF-8" pageEncoding="UTF-8"%> <%@ taglib uri="/struts-tags" prefix="s"%> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <!-- saved from url=(0048)http://localhost:8080/mango/product/list/1.jhtml --> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8"/> <title>传智网上商城</title> <link href="${pageContext.request.contextPath}/css/common.css" rel="stylesheet" type="text/css"/> <link href="${pageContext.request.contextPath}/css/product.css" rel="stylesheet" type="text/css"/> </head> <body> <div class="container header"> <div class="span5"> <div class="logo"> <a href="http://localhost:8080/mango/"> <img src="${pageContext.request.contextPath}/image/r___________renleipic_01/logo.gif" alt="传智播客"> </a> </div> </div> <div class="span9"> <div class="headerAd"> <img src="${pageContext.request.contextPath}/image/header.jpg" width="320" height="50" alt="正品保障" title="正品保障"> </div> </div> <%@ include file="menu.jsp" %> </div> <div class="container productList"> <div class="span6"> <div class="hotProductCategory"> <s:iterator var="c" value="#session.cList"> <dl> <dt> <a href="${pageContext.request.contextPath}/product_findByCid.action?cid=<s:property value="#c.cid"/>&page=1"><s:property value="#c.cname"/></a> </dt> <s:iterator var="cs" value="#c.categorySeconds"> <dd> <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="#cs.csid"/>&page=1"><s:property value="#cs.csname"/></a> </dd> </s:iterator> </dl> </s:iterator> </div> </div> <div class="span18 last"> <form id="productForm" action="${pageContext.request.contextPath}/image/蔬菜 - Powered By Mango Team.htm" method="get"> <div id="result" class="result table clearfix"> <ul> <s:iterator var="p" value="pageBean.list"> <li> <a href="${ pageContext.request.contextPath }/product_findByPid.action?pid=<s:property value="#p.pid"/>"> <img src="${pageContext.request.contextPath}/<s:property value="#p.image"/>" width="170" height="170" style="display: inline-block;"> <span style='color:green'> <s:property value="#p.pname"/> </span> <span class="price"> 商城价： ￥<s:property value="#p.shop_price"/> </span> </a> </li> </s:iterator> </ul> </div> <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="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=1" class="firstPage"> </a> <a href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="pageBean.page-1"/>" class="previousPage"> </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"/>"> </a> <a class="lastPage" href="${ pageContext.request.contextPath }/product_findByCid.action?cid=<s:property value="cid"/>&page=<s:property value="pageBean.totalPage"/>"> </a> </s:if> </s:if> <s:if test="csid != null"> <s:if test="pageBean.page != 1"> <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=1" class="firstPage"> </a> <a href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="pageBean.page-1"/>" class="previousPage"> </a> </s:if> <s:iterator var="i" begin="1" end="pageBean.totalPage"> <s:if test="pageBean.page != #i"> <a href="${ 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="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="pageBean.page+1"/>"> </a> <a class="lastPage" href="${ pageContext.request.contextPath }/product_findByCsid.action?csid=<s:property value="csid"/>&page=<s:property value="pageBean.totalPage"/>"> </a> </s:if> </s:if> </div> </form> </div> </div> <div class="container footer"> <div class="span24"> <div class="footerAd"> <img src="${pageContext.request.contextPath}/image/footer.jpg" width="950" height="52" alt="我们的优势" title="我们的优势"> </div> </div> <div class="span24"> <ul class="bottomNav"> <li> <a >关于我们</a> | </li> <li> <a>联系我们</a> | </li> <li> <a >诚聘英才</a> | </li> <li> <a >法律声明</a> | </li> <li> <a>友情链接</a> | </li> <li> <a target="_blank">支付方式</a> | </li> <li> <a target="_blank">配送方式</a> | </li> <li> <a >官网</a> | </li> <li> <a >论坛</a> </li> </ul> </div> <div class="span24"> <div class="copyright">Copyright©2005-2015 网上商城 版权所有</div> </div> </div> </body></html>