ApplicationInitializer.java

/*
 * Copyright 2017 OmniFaces
 *
 * 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 org.omnifaces;

import static java.util.logging.Level.SEVERE;

import java.util.Set;
import java.util.logging.Logger;

import javax.servlet.ServletContainerInitializer;
import javax.servlet.ServletContext;
import javax.servlet.ServletException;

import org.omnifaces.config.OmniFaces;
import org.omnifaces.facesviews.FacesViews;

/**
 * <p>
 * OmniFaces application initializer. This runs when the servlet container starts up.
 * This performs the following tasks:
 * <ol>
 * <li>Log OmniFaces version.
 * <li>Register {@link FacesViews} forwarding filter.
 * </ol>
 *
 * @author Bauke Scholtz
 * @since 2.0
 */
public class ApplicationInitializer implements ServletContainerInitializer {

	// Constants ------------------------------------------------------------------------------------------------------

	private static final Logger logger = Logger.getLogger(ApplicationInitializer.class.getName());


	static final String ERROR_OMNIFACES_INITIALIZATION_FAIL =
		"OmniFaces failed to initialize! Report an issue to OmniFaces.";

	// Actions --------------------------------------------------------------------------------------------------------

	@Override
	public void onStartup(Set<Class<?>> c, ServletContext servletContext) throws ServletException {
		logOmniFacesVersion();

		try {
			FacesViews.registerForwardingFilter(servletContext);
		}
		catch (Exception | LinkageError e) {
			logger.log(SEVERE, ERROR_OMNIFACES_INITIALIZATION_FAIL, e);
			throw e;
		}
	}

	private void logOmniFacesVersion() {
		logger.info("Using OmniFaces version " + OmniFaces.getVersion());
	}

}