Java开发网 - Re:求助-_-..jsp 传值的问题

Java开发网

您没有登录

» Java开发网 » Java EE 综合讨论区 » J2EE SDK

打印话题 寄给朋友 订阅主题

作者

Re:求助-_-..jsp 传值的问题 [Re:WILLIAMBALDWIN]

JiafanZhou

版主

发贴: 736
积分: 61

于 2008-06-05 17:25

First of all, your html source code is incomplete. the <head> and <body> tags are missing from both of your jsp files. So the result of these jsp pages will be incorrect.

WILLIAMBALDWIN wrote:
请问使两个jsp页面能传值有没有什么要求? 是不是两个页面必须通过form表单的action联系在一起

Now to answer your question here, I need to mention some of ideas of how Servlet and JSP sharing the data between pages.

There are 3 well-known containers that can be used to save data, they are:
- ServletRequest
- HttpSession
- ServletContext
All the above objects provide a get/setAttribute methods.

In the case here, you are using the implicit JSP variable request (Refers to the current request to the page) as the container to save date. You should be aware of the objects shared using request are accessible only for the life if a request.

Now think about the HTTP protocol, based on HTTP request and response, you have established a TCP connection with a 3 handshake and HTTP protocol has a request to your JSP page. Because you set an attribute in one JSP page, in order to let another JSP page knows this attribute, you need to forward this request to the second JSP page using a special jsp tag.


<jsp:forward page="/index.jsp" />

Another option is to use the HTTP session as a container.


String str=(String)session.getAttribute("msg"); // session is an implicit JSP variable

Of course you can think about using a ServletContext as well.

WILLIAMBALDWIN wrote:
是不是两个页面必须通过form表单的action联系在一起

Nope, this is not required.

Hope this helps.

Regards,
Jiafan

When I was a kid I used to pray every night for a new bike. Then I realized that The Lord doesn't work that way, so I stole one and asked him to forgive me.

话题树型展开

人气	标题	作者	字数	发贴时间
9393	求助-_-..jsp 传值的问题	WILLIAMBALDWIN	367	2008-06-05 16:24
7995	Re:求助-_-..jsp 传值的问题	JiafanZhou	1630	2008-06-05 17:25

已读帖子

新的帖子

被删除的帖子