Java Web 网络商城案例演示十（商品详情）

Java Web 网络商城案例演示十（商品详情）
用户点击商品图片或名称向服务端发起请求，将商品的id发送到服务端
在ProductServlet的findProductByPid当中获取到pid，根据pid查询商品信息，将获取到的商品放入request
ProductService
ProductDao
转发到jsp/product_info.jsp

原理分析

步骤实现

1、准备工作 /jsp/index.jsp修改链接

<c:forEach items="${hots }" var="p">

					<div class="col-md-2"
						style="text-align: center; height: 200px; padding: 10px 0px;">
						<a href="${pageContext.request.contextPath}/ProductServlet?method=findProductByPid&pid=${p.pid}"> <img
							src="${pageContext.request.contextPath}/${p.pimage}" width="130" height="130"
							style="display: inline-block;">
						</a>
						<p>
							<a href="${pageContext.request.contextPath}/ProductServlet?method=findProductByPid&pid=${p.pid}" style='color: #666'>${p.pname }</a>
						</p>
						<p>
							<font color="#E4393C" style="font-size: 16px">&yen;${p.shop_price }</font>
						</p>
					</div>
				</c:forEach>

ProductServlet

public class ProductServlet extends BaseServlet {
	// findProductByPid
	public String findProductByPid(HttpServletRequest request, HttpServletResponse response) throws Exception {
		String pid =  request.getParameter("pid");
		System.out.println("pid="+pid);
		ProductService productService = new ProductServiceImpl();
		Product product = productService.findProductByPid(pid);
		
		request.setAttribute("product", product);
		
		return "/jsp/product_info.jsp";
	}
}

ProductService

public interface ProductService {
	
	//查询最新商品
	List<Product> findHots() throws Exception;
	//查询最新最热商品
	List<Product> findNews() throws Exception;

	//查询详情
	Product findProductByPid(String pid)throws Exception;
}

ProductServiceImpl

public class ProductServiceImpl implements ProductService {
	ProductDao productDao = new ProductDaoImpl();
	@Override
	public List<Product> findHots() throws Exception {
		// TODO Auto-generated method stub
		return productDao.findHots();
	}
	@Override
	public List<Product> findNews() throws Exception {
		// TODO Auto-generated method stub
		return productDao.findNews();
	}
	@Override
	public Product findProductByPid(String pid) throws Exception {
		// TODO Auto-generated method stub
		return productDao.findProductByPid(pid);
	}
}

ProductDao

public interface ProductDao {
	List<Product> findHots() throws Exception;
	List<Product> findNews() throws Exception;
	Product findProductByPid(String pid)throws Exception;
}

ProductDaoImpl

public class ProductDaoImpl implements ProductDao {

	@Override
	public List<Product> findHots() throws Exception {
		// TODO Auto-generated method stub
		String sql = "SELECT * FROM product WHERE pflag=0 AND is_hot=1 ORDER BY pdate DESC LIMIT 0,9;";
		QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());
		return qr.query(sql, new BeanListHandler<Product>(Product.class));
	}

	@Override
	public List<Product> findNews() throws Exception {
		// TODO Auto-generated method stub
		String sql = "SELECT * FROM product WHERE pflag=0 ORDER BY pdate DESC LIMIT 0,9";
		QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());
		return qr.query(sql, new BeanListHandler<Product>(Product.class));
	}

	@Override
	public Product findProductByPid(String pid) throws Exception {
		// TODO Auto-generated method stub
		String sql = "select * from product where pid=?";
		QueryRunner qr = new QueryRunner(JDBCUtils.getDataSource());
		return qr.query(sql, new BeanHandler<Product>(Product.class),pid);
	}
}

					${product}:底层依次吊样个域对象上的*.getAttribute("keyName");
					寻找搭配request可以获取到一个对象
					$(product.pname);通过获取到的product对象去调用对象上getPname()方法的，返回值。