在JSF生命周期外由Servlet获得FacesContext及ManagedBeans

最新推荐文章于 2016-11-04 16:28:15 发布

翻译最新推荐文章于 2016-11-04 16:28:15 发布 · 1.3k 阅读

文章标签：

#servlet #jsf #class #string #cms #object

本文介绍了一种通过自定义Servlet启动JSF生命周期的方法。通过继承示例中的抽象类并实现processRequest方法，可以实现在点击链接时直接进入JSF生命周期。代码中详细展示了如何创建FacesContext实例，并设置必要的组件。

项目中需要通过一链接直接进入JSF生命周期, 苦思冥想无法解决. Google之, 得解. 现帖出那位老外的代码, 很有用的工具类.

public abstract class AbstractFacesServlet extends HttpServlet {



	/** Creates a new instance of AbstractFacesServlet */

	public AbstractFacesServlet() {

		super();

	}



	public void init(ServletConfig config) throws ServletException {

		super.init(config);

	}



	protected abstract void processRequest(HttpServletRequest request,

			HttpServletResponse response) throws ServletException, IOException;



	/**

	 * Handles the HTTP <code>GET</code> method.

	 * 

	 * @param request

	 *            servlet request

	 * @param response

	 *            servlet response

	 */

	protected void doGet(HttpServletRequest request,

			HttpServletResponse response) throws ServletException, IOException {

		processRequest(request, response);

	}



	protected void log(FacesContext facesContext, String message) {

		facesContext.getExternalContext().log(message);

	}



	/**

	 * Handles the HTTP <code>POST</code> method.

	 * 

	 * @param request

	 *            servlet request

	 * @param response

	 *            servlet response

	 */

	protected void doPost(HttpServletRequest request,

			HttpServletResponse response) throws ServletException, IOException {

		processRequest(request, response);

	}



	protected FacesContext getFacesContext(HttpServletRequest request,

			HttpServletResponse response) {

		FacesContext facesContext = FacesContext.getCurrentInstance();

		if (facesContext == null) {

			FacesContextFactory contextFactory = (FacesContextFactory) FactoryFinder

					.getFactory(FactoryFinder.FACES_CONTEXT_FACTORY);

			LifecycleFactory lifecycleFactory = (LifecycleFactory) FactoryFinder

					.getFactory(FactoryFinder.LIFECYCLE_FACTORY);

			Lifecycle lifecycle = lifecycleFactory

					.getLifecycle(LifecycleFactory.DEFAULT_LIFECYCLE);

			facesContext = contextFactory.getFacesContext(request.getSession()

					.getServletContext(), 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, "cms");

			facesContext.setViewRoot(view);

		}

		return facesContext;

	}



	protected Object getBean(String beanName, FacesContext facesContext) {

		return facesContext.getApplication().getVariableResolver().resolveVariable(facesContext, beanName);

	}



	// 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);

		}

	}

}

后面就不用多说了吧,继承此类,然后实现processRequest方法.