/*
    * Copyright 2009-2010 Capgemini
    * 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 net.sourceforge.statelessfilter.spring;
  
  import javax.servlet.ServletContext;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  import org.springframework.context.ApplicationContext;
  import org.springframework.web.context.support.WebApplicationContextUtils;
  
  /**
   * Checks for Spring.
   * 
   * @author Nicolas Richeton
   * 
   */
  public class SpringContextChecker {
  	private static Logger log = LoggerFactory
  			.getLogger(SpringContextChecker.class);
  
  	/**
  	 * Check is Spring is available and configured in the servlet context.
  	 * 
  	 * @param context
  	 * @return
  	 */
  	public static boolean checkForSpring(ServletContext context) {
  		try {
  			Class<?> contextUtils = Class
  					.forName("org.springframework.web.context.support.WebApplicationContextUtils");
  
  			if (contextUtils != null) {
  				ApplicationContext appContext = WebApplicationContextUtils
  						.getRequiredWebApplicationContext(context);
  				if (appContext != null) {
  					if (log.isInfoEnabled()) {
  						log
  								.info("Spring is available AND an application context has been found.");
  					}
  					return true;
  				}
  			}
  
  			return true;
  		} catch (Exception e) {
  			if (log.isInfoEnabled()) {
  				log.info("Spring is not available.");
  			}
  		}
  		return false;
  	}
  
  }