JAVA WEB_JSP的初步(10)

最新推荐文章于 2021-06-01 17:27:41 发布

原创最新推荐文章于 2021-06-01 17:27:41 发布 · 623 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#jsp #java #web #string #null #session

JSP,SERVLET 专栏收录该内容

27 篇文章

订阅专栏

本文详细介绍了如何使用Java的session对象实现网页计时器、登录测试和简单购物车功能。通过设置session，实现实时计数、用户登录验证以及商品加入购物车的操作。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1.使用session实现网页计时器。

<%@ page contentType="text/html;charset=GB2312"%>

<%!
	int number = 0;
	synchronized void countPeople() {
		number++;
	}
%>
<%
	if (session.isNew()) {
		countPeople();
		String str = String.valueOf(number);
		session.setAttribute("count", str);
	}
	String sessionID = session.getId();
%>

<HTML>
	<head>
		<title>session对象示例</title>
	</head>
	<BODY>
		<h2>session对象示例</h2>
		<P> sessionID is：<%=sessionID%> <P>
			<%=(String) session.getAttribute("count")%>号顾客，欢迎你归来。
	<BODY>
<HTML>

2.使用session内置对象，实现登录测试

<%@ page contentType="text/html;charset=GB2312"%>

<html>
	<head>
		<title>Login.jsp</title>
	</head>
	<body>

		<h2>
			session登录测试
		</h2>
		<form action=Login.jsp method="POST">
			Login Name:
			<input type="text" name="Name">
			<br>
			Login Password:
			<input type="text" name="Password">
			<br>
			<input type="submit" value="Send">
			<br>
			<form>

				<%
					if (request.getParameter("Name") != null
							&& request.getParameter("Password") != null) {
						String Name = request.getParameter("Name");
						String Password = request.getParameter("Password");

						if (Name.equals("mars") && Password.equals("1234")) {
							session.setAttribute("Login", "OK");
							response.sendRedirect("Member.jsp");
						} else {
							out.println("登录错误，请输入正确名称");
						}
					}
				%>
			
	</body>
</html>

member.jsp

<%@ page contentType="text/html;charset=GB2312"%>

<html>
	<head>
		<title>Member.jsp</title>
	</head>
	<body>

		<h2>
			session登录测试
		</h2>
		<%
			String Login = (String) session.getAttribute("Login");

			if (Login != null && Login.equals("OK")) {
				out.println("欢迎进入");
				session.invalidate();
			} else {
				out.println("请先登录，谢谢");
				out.println("<br>经过五秒之后，网页会自动返回Login.jsp");

				response.setHeader("Refresh", "5;URL=Login.jsp");
			}
		%>

	</body>
</html>

3.用session实现简单的购物车功能。

buy1.jsp

<%@ page contentType="text/html;charset=GBK"%>
<HTML>
	<BODY>
		<%
			request.setCharacterEncoding("GBK");
			if (request.getParameter("c1") != null) {
				session.setAttribute("s1", request.getParameter("c1"));
			}
			if (request.getParameter("c2") != null) {
				session.setAttribute("s2", request.getParameter("c2"));
			}
			if (request.getParameter("c3") != null) {
				session.setAttribute("s3", request.getParameter("c3"));
			}
		%>

		稀世珍宝，慈禧戴过的各种宝石，全场卖两块。
		<br>
		<FORM METHOD="POST" action="buy1.jsp">
			<p>
				<input type="checkbox" name="c1" value="珍珠">
				珍珠
			</p>
			<p>
				<input type="checkbox" name="c2" value="翡翠">
				翡翠
			</p>
			<p>
				<input type="checkbox" name="c3" value="玛瑙">
				玛瑙
			</p>
			<p>
				<input type="submit" value="提交" name="B1">
				<input type="reset" value="重写" name="B2">
				<a href="buy2.jsp">我再看看</a>
				<a href="display.jsp">查看购物车</a>
			</P>
		</FORM>
	</BODY>
</HTML>

buy2.jsp

<%@ page contentType="text/html;charset=GBK"%>
<HTML>
	<BODY>
		<%
			request.setCharacterEncoding("GBK");
			if (request.getParameter("b1") != null) {
				session.setAttribute("s4", request.getParameter("b1"));
			}
			if (request.getParameter("b2") != null) {
				session.setAttribute("s5", request.getParameter("b2"));
			}
			if (request.getParameter("b3") != null) {
				session.setAttribute("s6", request.getParameter("b3"));
			}
		%>
		计算机中的宝书！全场买一送一，各种绝版书免费送
		<form method="POST" action="buy2.jsp">
			<p>
				<input type="checkbox" name="b1" value="*">*
			</p>
			<p>
				<input type="checkbox" name="b2" value="&">&
			</p>
			<p>
				<input type="checkbox" name="b3" value="#">#
			</p>
			<p>
				<input type="submit" value="提交" name="x1">
				<input type="reset" value="重写" name="B2">
				<a href="buy1.jsp">我在看看</a>
				<a href="display.jsp">查看购物车</a>
			</P>
		</FORM>
	</BODY>
</HTML>

display.jsp

<%@ page contentType="text/html;charset=GBK"%>
<HTML>
	<BODY>
		赶快结算吧！<br>
		<%
		String str = "";
		if (session.getAttribute("s1") != null) {
			str = (String) session.getAttribute("s1");
			out.print(str + "<br>");

		}
		if (session.getAttribute("s2") != null) {
			str = (String) session.getAttribute("s2");
			out.print(str + "<br>");
		}
		if (session.getAttribute("s3") != null) {

			str = (String) session.getAttribute("s3");
			out.print(str + "<br>");
		}
		if (session.getAttribute("s4") != null) {
			str = (String) session.getAttribute("s4");
			out.print(str + "<br>");
		}
		if (session.getAttribute("s5") != null) {
			str = (String) session.getAttribute("s5");
			out.print(str + "<br>");
		}
		if (session.getAttribute("s6") != null) {
			str = (String) session.getAttribute("s6");
			out.print(str + "<br>");
		}
	%>
	</BODY>
</HTML>