FacesContext and “Servlet” Context

问题

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

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 ?

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

Thanks.

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

回答1:

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();
    // ...
}

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());

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);

回答2:

ServletContext servletContext = (ServletContext)FacesContext.getCurrentInstance().getExternalContext().getContext();

来源：https://stackoverflow.com/questions/3754327/facescontext-and-servlet-context

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java

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servlets

facescontext