GeomajasController.java

/*
 * This is part of Geomajas, a GIS framework, http://www.geomajas.org/.
 *
 * Copyright 2008-2015 Geosparc nv, http://www.geosparc.com/, Belgium.
 *
 * The program is available in open source according to the GNU Affero
 * General Public License. All contributions in this program are covered
 * by the Geomajas Contributors License Agreement. For full licensing
 * details, see LICENSE.txt in the project root.
 */
package org.geomajas.gwt.server.mvc;

import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.geomajas.annotation.Api;
import org.geomajas.command.CommandDispatcher;
import org.geomajas.command.CommandResponse;
import org.geomajas.gwt.client.GeomajasService;
import org.geomajas.gwt.client.command.GwtCommand;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.context.ServletConfigAware;
import org.springframework.web.servlet.ModelAndView;

import com.google.gwt.user.server.rpc.RemoteServiceServlet;
import com.google.gwt.user.server.rpc.SerializationPolicy;

/**
 * Geomajas GWT controller, implements communication between GWT face and back-end.
 * 
 * @author Jan De Moerloose
 * @since 2.0.0
 */
@Controller("/geomajasService")
@Api
public class GeomajasController extends RemoteServiceServlet implements GeomajasService, ServletConfigAware {

	private static final long serialVersionUID = 100L;

	@Autowired
	private CommandDispatcher commandDispatcher;

	@Autowired(required = false)
	private ServletContext servletContext;
	
	private SerializationPolicyLocator serializationPolicyLocator;
	
	private final Logger log = LoggerFactory.getLogger(GeomajasController.class);

	/**
	 * Implements Spring Controller interface method.
	 * <p/>
	 * Call {@link RemoteServiceServlet#doPost(HttpServletRequest, HttpServletResponse)} method and return null.
	 *
	 * @param request current HTTP request
	 * @param response current HTTP response
	 * @return a ModelAndView to render, or null if handled directly
	 * @throws Exception in case of errors
	 */
	@RequestMapping("/geomajasService")
	public ModelAndView handleRequest(HttpServletRequest request, HttpServletResponse response) throws Exception {
		doPost(request, response);
		return null;
	}

	/**
	 * Returns this controller's GWT-RPC serialization policy loader. May be null in case the built-in policy loading
	 * strategy is used.
	 * 
	 * @return the policy loader
	 */
	@Api
	public SerializationPolicyLocator getSerializationPolicyLocator() {
		return serializationPolicyLocator;
	}
	
	/**
	 * Sets a custom GWT-RPC serialization policy loader. If null, the built-in policy loading strategy is used.
	 * 
	 * @param serializationPolicyLocator the new policy loader
	 */
	@Api
	public void setSerializationPolicyLocator(SerializationPolicyLocator serializationPolicyLocator) {
		this.serializationPolicyLocator = serializationPolicyLocator;
	}

	/**
	 * Gets the {@link SerializationPolicy} for given module base URL and strong name if there is one.
	 * 
	 * Use {@link #setSerializationPolicyLocator(SerializationPolicyLocator)} to provide an alternative approach.
	 * 
	 * @param request the HTTP request being serviced
	 * @param moduleBaseURL as specified in the incoming payload
	 * @param strongName a strong name that uniquely identifies a serialization policy file
	 * @return a {@link SerializationPolicy} for the given module base URL and strong name, or <code>null</code> if
	 *         there is none
	 */
	protected SerializationPolicy doGetSerializationPolicy(HttpServletRequest request, String moduleBaseURL,
			String strongName) {
		if (getSerializationPolicyLocator() == null) {
			return super.doGetSerializationPolicy(request, moduleBaseURL, strongName);
		} else {
			return getSerializationPolicyLocator().loadPolicy(request, moduleBaseURL, strongName);
		}
	}
	
	@Override
	protected void doUnexpectedFailure(Throwable e) {
		log.error("Unexpected GWT-RPC failure", e);
		super.doUnexpectedFailure(e);
	}

	/**
	 * Execute a GWT RPC command request, and return the response. These request come from the client, and the response
	 * is sent back to the client. We use a {@link CommandDispatcher} to actually execute the command.
	 */
	public CommandResponse execute(GwtCommand request) {
		if (request != null) {
			return commandDispatcher.execute(request.getCommandName(), request.getCommandRequest(),
					request.getUserToken(), request.getLocale());
		}
		return null;
	}

	public ServletContext getServletContext() {
		if (null == servletContext) {
			throw new IllegalStateException("getServletContext() cannot be used outside web context");
		}
		return servletContext;
	}

	public void setServletConfig(ServletConfig servletConfig) {
		try {
			super.init(servletConfig);
		} catch (ServletException e) {
			throw new IllegalStateException("init(servletConfig) failed", e);
		}
	}
}