Ajax+jsp+Servlet 实现购物车

package com.hexiang.demo.shoppingcart.biz; import java.io.Serializable; import java.sql.Connection; import java.sql.PreparedStatement; import java.sql.ResultSet; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; import com.hexiang.demo.shoppingcart.db.DBUtils; /** * Product 产品类 */ public class Product implements Serializable{ private static final long serialVersionUID = 4300705719350308488L; private String productId = null; // 产品编号 private String productName = null; // 产品名称 private double productPirce = 0.0; //产品价格 private int productNum = 0; // 产品数量 /** * getProductId 获取产品编号 */ public String getProductId() { return productId; } /** * setProductId 设置产品编号 */ public void setProductId(String productId) { this.productId = productId; } /** * getProductName 获取产品名称 */ public String getProductName() { return productName; } /** * setProductName 设置产品名称 */ public void setProductName(String productName) { this.productName = productName; } /** * getProductPirce 获取产品价格 */ public double getProductPirce() { return productPirce; } /** * setProductPirce 设置产品价格 */ public void setProductPirce(double productPirce) { this.productPirce = productPirce; } /** * getProductNum 获取产品数量 */ public int getProductNum() { return productNum; } /** * setProductNum 设置产品数量 */ public void setProductNum(int productNum) { this.productNum = productNum; } /** * Product 默认构造方法 */ public Product(){ } /** * 通过产品ID编号构造一个产品 */ public Product(String productId){ String sql = "select pid,pname,price from products where pid = ?"; Connection conn = null; // 声明Connection对象 PreparedStatement pstmt = null; // 声明PreparedStatement对象 ResultSet rs = null; // 声明ResultSet对象 try { conn = DBUtils.getConnection(); pstmt = conn.prepareStatement(sql); pstmt.setString(1, productId); rs = pstmt.executeQuery(); while(rs.next()){ this.productId = rs.getString("pid"); this.productName = rs.getString("pname"); this.productPirce = rs.getInt("price"); this.productNum = 1; } } catch (SQLException e) { System.out.println("com.hexiang.shoppingcart.biz.Product: cannot executeQuery ,because "+e.getMessage()); e.printStackTrace(); } finally{ DBUtils.close(rs); //关闭结果集ResultSet DBUtils.close(pstmt); //关闭PreparedStatement DBUtils.close(conn); //关闭连接Connection } } public List<Product> initProduct(){ String sql = "select pid,pname,price from products"; List<Product> products = new ArrayList<Product>(); // 声明List对象，用于存放产品信息 Connection conn = null; // 声明Connection对象 PreparedStatement pstmt = null; // 声明PreparedStatement对象 ResultSet rs = null; // 声明ResultSet对象 try { conn = DBUtils.getConnection(); pstmt = conn.prepareStatement(sql); rs = pstmt.executeQuery(); Product product = null; while(rs.next()){ product = new Product(); product.setProductId(rs.getString("pid")); product.setProductName(rs.getString("pname")); product.setProductPirce(rs.getDouble("price")); product.setProductNum(1); products.add(product); } } catch (SQLException e) { System.out.println("com.hexiang.shoppingcart.biz.Product: cannot executeQuery ,because "+e.getMessage()); } finally{ DBUtils.close(rs); //关闭结果集ResultSet DBUtils.close(pstmt); //关闭PreparedStatement DBUtils.close(conn); //关闭连接Connection } return products; } }