Ajax+servlet练习题

完成商品购买功能

apple.jsp:

<%@ 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">
<script type="text/javascript" src="js/jquery-3.6.0.js"></script>
<script type="text/javascript">
    $(function(){
        num=$(".num").val();
        dosum=function(){
            $.get('AppleController?num='+num,function(data){
            　　 alert("一共"+data+"元。");
                console.log("购买"+num+"个，一共"+data+"元。");
            })
        }
    });
</script>
<title>苹果</title>
</head>
<body>
    <h1>苹果店</h1>
    <h2>5元1个苹果</h2>
    <input class="num" type="text" size=12 placeholder="输入"/>
    <input type="button" value="提交" onclick="dosum()"/>
</body>
</html>

AppleController.java

protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        int num = Integer.parseInt(request.getParameter("num"));
        PrintWriter pw=response.getWriter();
        pw.print(num*5);
        pw.flush();
        pw.close();
    }