com.liferay.portletmvc4spring.ViewRendererServlet Maven / Gradle / Ivy
/**
* Copyright (c) 2000-2020 the original author or authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.liferay.portletmvc4spring;
import java.io.IOException;
import java.util.Map;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.springframework.web.servlet.DispatcherServlet;
import org.springframework.web.servlet.View;
import org.springframework.web.util.NestedServletException;
/**
* ViewRendererServlet is a bridge servlet that supports PortletMVC4Spring.
*
* For usage with Portlets, this Servlet is necessary to force the portlet container to convert the PortletRequest to
* a ServletRequest, which it has to do when including a resource via the PortletRequestDispatcher. This allows for
* reuse of the entire Servlet-based View support even in a Portlet environment.
*
*
The actual mapping of the bridge servlet is configurable in the DispatcherPortlet, via a "viewRendererUrl"
* property. The default is "/WEB-INF/servlet/view", which is just available for internal resource dispatching.
*
* @author William G. Thompson, Jr.
* @author John A. Lewis
* @author Juergen Hoeller
* @author Neil Griffin
* @since 5.1
*/
@SuppressWarnings("serial")
public class ViewRendererServlet extends HttpServlet {
/**
* Request attribute to hold current web application context. Otherwise only the global web app context is
* obtainable by tags etc.
*
* @see org.springframework.web.servlet.support.RequestContextUtils#findWebApplicationContext
*/
public static final String WEB_APPLICATION_CONTEXT_ATTRIBUTE = DispatcherServlet.WEB_APPLICATION_CONTEXT_ATTRIBUTE;
/** Name of request attribute that holds the View object */
public static final String VIEW_ATTRIBUTE = ViewRendererServlet.class.getName() + ".VIEW";
/** Name of request attribute that holds the model Map */
public static final String MODEL_ATTRIBUTE = ViewRendererServlet.class.getName() + ".MODEL";
@Override
protected final void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException,
IOException {
processRequest(request, response);
}
@Override
protected final void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException,
IOException {
processRequest(request, response);
}
/**
* Process this request, handling exceptions. The actually event handling is performed by the abstract {@code
* renderView()} template method.
*
* @see #renderView
*/
protected final void processRequest(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
try {
renderView(request, response);
}
catch (ServletException ex) {
throw ex;
}
catch (IOException ex) {
throw ex;
}
catch (Exception ex) {
throw new NestedServletException("View rendering failed", ex);
}
}
/**
* Retrieve the View instance and model Map to render and trigger actual rendering.
*
* @param request current HTTP request
* @param response current HTTP response
*
* @throws Exception in case of any kind of processing failure
*
* @see org.springframework.web.servlet.View#render
*/
@SuppressWarnings("unchecked")
protected void renderView(HttpServletRequest request, HttpServletResponse response) throws Exception {
View view = (View) request.getAttribute(VIEW_ATTRIBUTE);
if (view == null) {
throw new ServletException("Could not complete render request: View is null");
}
Map model = (Map) request.getAttribute(MODEL_ATTRIBUTE);
view.render(model, request, response);
}
}