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在?Faces realm外,例如 在 ?filter 或者servlet中,當 FacesContent.getCurrentInstance() 返回null時候,你可以使用FacesContextFactory來得到FacesContext,下面是一個示例.
//?You?need?an?inner?class?to?be?able?to?call?FacesContext.setCurrentInstance
//?since?it's?a?protected?method
private?abstract?static?class?InnerFacesContext?extends?FacesContext
{
??protected?static?void?setFacesContextAsCurrentInstance(FacesContext?facesContext)?{
????FacesContext.setCurrentInstance(facesContext);
??}
}
private?FacesContext?getFacesContext(ServletRequest?request,?ServletResponse?response)?{
??//?Try?to?get?it?first
??FacesContext?facesContext?=?FacesContext.getCurrentInstance();
??if?(facesContext?!=?null)?return?facesContext;
??FacesContextFactory?contextFactory?=?(FacesContextFactory)FactoryFinder.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);
??LifecycleFactory?lifecycleFactory?=?(LifecycleFactory)FactoryFinder.getFactory(FactoryFinder.LIFECYCLE_FACTORY);
??Lifecycle?lifecycle?=?lifecycleFactory.getLifecycle(LifecycleFactory.DEFAULT_LIFECYCLE);
??//?Either?set?a?private?member?servletContext?=?filterConfig.getServletContext();
??//?in?you?filter?init()?method?or?set?it?here?like?this:
??//?ServletContext?servletContext?=?((HttpServletRequest)request).getSession().getServletContext();
??//?Note?that?the?above?line?would?fail?if?you?are?using?any?other?protocol?than?http
??//?Doesn't?set?this?instance?as?the?current?instance?of?FacesContext.getCurrentInstance
??facesContext?=?contextFactory.getFacesContext(servletContext,?request,?response,?lifecycle);
??//?Set?using?our?inner?class
??InnerFacesContext.setFacesContextAsCurrentInstance(facesContext);
??//?set?a?new?viewRoot,?otherwise?context.getViewRoot?returns?null
??UIViewRoot?view?=?facesContext.getApplication().getViewHandler().createView(facesContext,?"yourOwnID");
facesContext.setViewRoot(view);
??return?facesContext;
} |