FacesContext和“Servlet”上下文 [英] FacesContext and "Servlet" Context

问题描述

是否有任何与FacesContext等效的东西，但是在servlet环境中？

is there any equivalent to FacesContext, but in servlet environment?

我有一些DAOSessionManager来处理我的数据库的事务。当使用JSF编写当前页面时，我可以使用FacesContext来识别当前的http请求，但是关于servlet的那些呢？

I have some DAOSessionManager that handles transaction to my database. I can use the FacesContext to identify the current http request when the current page is written using JSF, but what about servlet ones ?

我找不到任何方法来获取当前的Servlet上下文，或httpRequest ...

I can't find any way to get the current Servlet context, or httpRequest...

谢谢。

PS：是的，有一个参考来自我的DAO层的FacesContext是一个耻辱，但这是一个开始。

PS : yes, having a reference to FacesContext from my DAO layer is a shame, but that's a start.

推荐答案

这是 ServletContext 。它在servlet类中由继承的提供 getServletContext（） 方法。

It's the ServletContext. It's available inside servlet classes by the inherited getServletContext() method.

protected void doGet(HttpServletRequest request, HttpServletResponse response) {
    ServletContext context = getServletContext();
    // ...
}

与<$ c的主要区别$ c> FacesContext 是 ServletContext 不是 ThreadLocal ，因此您无法从当前线程静态地获取它例如 FacesContext＃getCurrentInstance（） 。你真的需要传递 ServletContext 参考DAO方法，无论你需要它：

The major difference with FacesContext is that the ServletContext isn't ThreadLocal, so you cannot obtain it "statically" from the current thread like FacesContext#getCurrentInstance() does. You really need to pass the ServletContext reference around into the DAO methods wherever you need it:

someDAO.doSomething(getServletContext());

或者更好的是，为避免紧密耦合，只需从中提取所需信息并传递给它： / p>

Or better yet, to avoid tight coupling, just extract the desired information from it and pass it:

Object interestingData = getServletContext().getAttribute("interestingData");
someDAO.doSomething(interestingData);

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