Ajax_典型应用_购物车添加商品

最新推荐文章于 2023-06-01 11:40:23 发布

原创最新推荐文章于 2023-06-01 11:40:23 发布 · 1.7k 阅读

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本文介绍了一个使用Java实现的简易购物车系统。该系统通过Servlet接收HTTP请求，处理商品加入购物车操作，并利用JSON格式返回更新后的购物车状态。文章详细展示了如何创建购物车对象、添加商品及更新购物车信息。

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<%@ page language="java" contentType="text/html; charset=utf-8"
    pageEncoding="utf-8"%>
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Insert title here</title>
<script type="text/javascript" src="${pageContext.request.contextPath}/js/jquery-1.7.2.js"></script>
<script type="text/javascript">
	$(function(){
		var isHasCart="${sessionScope.sc==null}";
		
		if(isHasCart=="true"){
			$("#cartstatus").hide();
		}else{
			$("#cartstatus").show();
			
			$("#bookName").text("${sessionScope.sc.bookName}");
			$("#totalBookNumber").text("${sessionScope.sc.totalBookNumber}");
			$("#totalMoney").text("${sessionScope.sc.totalMoney}");
		}
		$("a").click(function(){
			$("#cartstatus").show();
			
			var url=this.href;
			var args={"time":new Date()};
			
			$.getJSON(url,args,function(data){
				$("#bookName").text(data.bookName);
				$("#totalBookNumber").text(data.totalBookNumber);
				$("#totalMoney").text(data.totalMoney);
			});
			return false;
		});
	});
</script>
</head>
<body>
<div id="cartstatus">
您已经将 <span id="bookName"></span> 加入到购物车，
购物车中共有 <span id="totalBookNumber"></span> 本书，
总价格  <span id="totalMoney"></span> 元.
<hr>
</div>
<br/><br/>
Java <a href="${pageContext.request.contextPath}/addToCart?id=java&price=11">加入购物车</a>
<br/><br/>
JavaWEB <a href="${pageContext.request.contextPath}/addToCart?id=javaweb&price=22">加入购物车</a>
<br/><br/>
JavaScript <a href="${pageContext.request.contextPath}/addToCart?id=javascript&price=33">加入购物车</a>
<br/><br/>
</body>
</html>

package org.java.beans;

public class ShoppingCarItem {

	private int number;
	private String bookName;
	private int price;
	public int getNumber() {
		return number;
	}
	public void setNumber(int number) {
		this.number = number;
	}
	public String getBookName() {
		return bookName;
	}
	public void setBookName(String bookName) {
		this.bookName = bookName;
	}
	public int getPrice() {
		return price;
	}
	public void setPrice(int price) {
		this.price = price;
	}
	
}

package org.java.beans;

import java.util.HashMap;
import java.util.Map;

public class ShoppingCart {

	private Map<String,ShoppingCarItem> items=new HashMap<String,ShoppingCarItem>();
	private String bookName;
	public String getBookName() {
		return bookName;
	}

	public void setBookName(String bookName) {
		this.bookName = bookName;
	}

	public void addToCart(String bookName,int price){
		this.bookName=bookName;
		if(items.containsKey(bookName)){
			ShoppingCarItem item=items.get(bookName);
			item.setNumber(item.getNumber()+1);
		}else{
			ShoppingCarItem item=new ShoppingCarItem();
			item.setBookName(bookName);
			item.setPrice(price);
			item.setNumber(1);
			
			items.put(bookName, item);
		}
	}
	
	public int getTotalBookNumber(){
		int total=0;
		for(ShoppingCarItem item:items.values()){
			total+=item.getNumber();
		}
		return total;
	}
	
	public int getTotalMoney(){
		int money=0;
		
		for(ShoppingCarItem item:items.values()){
			money+=item.getNumber()*item.getPrice();
		}
		return money;
	}
}

package org.java.test;

import java.io.IOException;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;

import org.java.beans.ShoppingCart;

/**
 * Servlet implementation class AddToCartServlet
 */
@WebServlet("/addToCart")
public class AddToCartServlet extends HttpServlet {
	private static final long serialVersionUID = 1L;
       
    /**
     * @see HttpServlet#HttpServlet()
     */
    public AddToCartServlet() {
        super();
        // TODO Auto-generated constructor stub
    }

	/**
	 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		doPost(request, response);
	}

	/**
	 * @see HttpServlet#doPost(HttpServletRequest request, HttpServletResponse response)
	 */
	protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
		//1.获取请求参数id,price
		String bookName=request.getParameter("id");
		int price=Integer.parseInt(request.getParameter("price"));
		//2.获取购物车对象
		HttpSession session=request.getSession();
		ShoppingCart sc=(ShoppingCart)session.getAttribute("sc");
		if(sc==null){
			sc=new ShoppingCart();
			session.setAttribute("sc", sc);
		}
		//3.把点击选项加入到购物车
		sc.addToCart(bookName, price);
		//4.准备响应的json对象：{"bookName":"java","totalBookNumber":1,"totalMoney":1}
		//若从服务端返回json字符串，属性名必须用双引号
		StringBuilder result=new StringBuilder();
		// JackSon 根据getter()来定位Java对象的属性
		//org.codehaus.jackson.map.ObjectMapper writeValueAsString():Java对象-->json字符串
		//jackson-annotations jackson-core jackson-databind  jar包
		//可以在类的getter方法上添加注解：org.codehaus.jackson.annotate.JsonIgnore。在转为json字符串时可以忽略该属性
		result.append("{")
		.append("\"bookName\":\""+bookName+"\"").append(",")
		.append("\"totalBookNumber\":"+sc.getTotalBookNumber()).append(",")
		.append("\"totalMoney\":"+sc.getTotalMoney()).append("}");
		//5.响应json对象
		response.setContentType("text/javascript");
		response.getWriter().print(result.toString());
	}

}

                // JackSon 根据getter()来定位Java对象的属性
		//org.codehaus.jackson.map.ObjectMapper writeValueAsString():Java对象-->json字符串
		//jackson-annotations jackson-core jackson-databind  jar包
		//可以在类的getter方法上添加注解：org.codehaus.jackson.annotate.JsonIgnore。在转为json字符串时可以忽略该属性