package com.atlassian.johnson.context;
   
   import com.atlassian.johnson.Johnson;
   
   import javax.servlet.ServletContextEvent;
   import javax.servlet.ServletContextListener;
   
   /**
    * Initialises and terminates {@link Johnson} with the servlet container.
   * <p/>
   * In web environments, this is the preferred mechanism for managing Johnson's lifecycle, allowing it to be initialised
   * and terminated in a thread-safe context. This listener should be registered before any others except, if applicable,
   * those that setup logging.
   * <p/>
   * To use this listener, add the following to web.xml:
   * <pre>
   * <code>&lt;listener&gt;
   *     &lt;listener-class&gt;com.atlassian.johnson.context.JohnsonContextListener&lt;/listener-class&gt;
   * &lt;/listener&gt;
   * </code>
   * </pre>
   *
   * @since 2.0
   */
  public class JohnsonContextListener implements ServletContextListener
  {
      /**
       * Terminates {@link Johnson}.
       * 
       * @param event the context event
       * @see Johnson#terminate(javax.servlet.ServletContext)
       */
      public void contextDestroyed(ServletContextEvent event)
      {
          Johnson.terminate(event.getServletContext());
      }
  
      /**
       * Initialises {@link Johnson}.
       *
       * @param event the context event
       * @see Johnson#initialize(javax.servlet.ServletContext)
       */
      public void contextInitialized(ServletContextEvent event)
      {
          Johnson.initialize(event.getServletContext());
      }
  }