我可以关闭 web.xml 中的 HttpSession 吗? [英] Can I turn off the HttpSession in web.xml?

问题描述

我想完全消除 HttpSession - 我可以在 web.xml 中这样做吗?我确信有容器特定的方法可以做到这一点(当我进行 Google 搜索时，这就是搜索结果拥挤的原因).

附言这是一个坏主意吗?我更喜欢在我真正需要它们之前完全禁用它们.

解决方案

我想彻底消除HttpSession

您不能完全禁用它.您需要做的就是不要通过request.getSession() 或request.getSession(true) 来处理它Web 应用程序代码中的任何位置，并通过设置 <%@page session="false"%> 来确保您的 JSP 不会隐式执行此操作.

如果您主要关心的是禁用在 HttpSession 幕后使用的 cookie，那么您可以在 Java EE 5/Servlet 2.5 中仅在特定于服务器的 webapp 配置中这样做.例如，在 Tomcat 中，您可以在 元素中将 cookies 属性设置为 false.

另请参阅此 Tomcat 特定文档.这样，会话将不会保留在未重写 URL 的后续请求中——仅当您出于某种原因从请求中获取它时.毕竟，如果你不需要它，只是不要抢它，那么它根本不会被创建/保留.

或者，如果您已经使用 Java EE 6/Servlet 3.0 或更新版本，并且真的想通过 web.xml 来实现，那么您可以使用新的 <cookieweb.xml 中的 -config> 元素，如下所示将最大年龄归零:

<会话超时>1</会话超时><cookie-config><max-age>0</max-age></cookie-config></session-config>

如果您想在 Web 应用程序中进行硬编码，以便 getSession() 永远不会返回 HttpSession(或空"HttpSession)，那么你需要创建一个过滤器来监听 /* 的 url-pattern 用 HttpServletRequestWrapper 实现，它返回所有 getSession() 方法 null，或者一个虚拟的自定义 HttpSession 实现，它什么都不做，甚至抛出 UnsupportedOperationException.>

@Overridepublic void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) 抛出 IOException, ServletException {chain.doFilter(新的 HttpServletRequestWrapper((HttpServletRequest)请求){@覆盖公共 HttpSession getSession() {返回空；}@覆盖公共 HttpSession getSession(布尔创建){返回空；}}， 回复);}

<小时><块引用>

P.S.这是一个坏主意吗?我更喜欢在我真正需要它们之前完全禁用它们.

如果你不需要它们，就不要使用它们.就这样.真的:)

I would like to eliminate the HttpSession completely - can I do this in web.xml? I'm sure there are container specific ways to do it (which is what crowds the search results when I do a Google search).

P.S. Is this a bad idea? I prefer to completely disable things until I actually need them.

解决方案

I would like to eliminate the HttpSession completely

You can't entirely disable it. All you need to do is to just not to get a handle of it by either request.getSession() or request.getSession(true) anywhere in your webapplication's code and making sure that your JSPs don't implicitly do that by setting <%@page session="false"%>.

If your main concern is actually disabling the cookie which is been used behind the scenes of HttpSession, then you can in Java EE 5 / Servlet 2.5 only do so in the server-specific webapp configuration. In for example Tomcat you can set the cookies attribute to false in <Context> element.

<Context cookies="false">

Also see this Tomcat specific documentation. This way the session won't be retained in the subsequent requests which aren't URL-rewritten --only whenever you grab it from the request for some reason. After all, if you don't need it, just don't grab it, then it won't be created/retained at all.

Or, if you're already on Java EE 6 / Servlet 3.0 or newer, and really want to do it via web.xml, then you can use the new <cookie-config> element in web.xml as follows to zero-out the max age:

<session-config>
    <session-timeout>1</session-timeout>
    <cookie-config>
        <max-age>0</max-age>
    </cookie-config>
</session-config>

If you want to hardcode in your webapplication so that getSession() never returns a HttpSession (or an "empty" HttpSession), then you'll need to create a filter listening on an url-pattern of /* which replaces the HttpServletRequest with a HttpServletRequestWrapper implementation which returns on all getSession() methods null, or a dummy custom HttpSession implementation which does nothing, or even throws UnsupportedOperationException.

@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
    chain.doFilter(new HttpServletRequestWrapper((HttpServletRequest) request) {
        @Override
        public HttpSession getSession() {
            return null;
        }
        @Override
        public HttpSession getSession(boolean create) {
            return null;
        }
    }, response);
}

---

P.S. Is this a bad idea? I prefer to completely disable things until I actually need them.

If you don't need them, just don't use them. That's all. Really :)

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