1. JSP的内置对象有
request,请求对象,代表来自客户端的请求
response, 响应对象,代表对客户端的响应
out,输出对象,通过out对象发送的内容将是浏览器需要显示的内容。
application 应用程序对象,负责提供应用程序在服务器中运行时提供的一些全局信息。
config 配置对象
page 页面对象
exception 异常对象
pageContext 页面上下午对象
session 会画对象, 代表服务器与客户端所建立的会话,当需要保存在不同的JSP页面中保留客户信息的情况下使用,比如在线购物、客户轨迹跟踪等。
2. request,out对象的使用
创建login.jsp, result.jsp
login.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"> <title>Insert title here</title> </head> <body> <form action="result.jsp" method="post"> username: <input type="text" name="username1"><br> password: <input type="password" name="password1"><br> <input type="submit" value="submit" > <input type="reset" value="reset" > </form> </body> </html>
result.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"> <title>Insert title here</title> </head> <body> <% String username = request.getParameter("username1"); String password = request.getParameter("password1"); out.println("username:" + username + "<br>"); out.println("password:" + password + "<br>"); System.out.println("username:" + username ); System.out.println("password:" + password ); %> </body> </html>
result.jsp 使用了request和out对象。
3. session对象的使用
session1.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"> <title>Insert title here</title> </head> <body> <form action="session2.jsp"> 姓名 <input type="text" name="username"> <input type="submit" value="提交"> </form> </body> </html>
session2.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"> <title>Insert title here</title> </head> <body> <% String username = request.getParameter("username"); session.setAttribute("LogName", username); %> 你的名字是 <%=username %>已經写入session <br> <a href='session3.jsp'>check</a> </body> </html>
session3.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"> <title>Insert title here</title> </head> <body> session值为: <% String yourname = (String)session.getAttribute("LogName"); if(yourname == null) { %> 您还未登录 <% } else { %> "<%=yourname %>"已经登录 <%} %> </body> </html>
作者:Work Hard Work Smart
出处:http://www.cnblogs.com/linlf03/
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