/*
    * Replica is published under the terms
    * of the Apache Software License.
    */
   package replica.core;
   
   import java.util.logging.Logger;
   
   import replica.command.Command;
  import replica.server.ServerProcess;
  import replica.session.Session;
  import replica.session.SessionManager;
  
  /***
   * Base command class for all server commands.
   * 
   * @author Pedro Costa
   * @author Helder Silva
   * @since 20/Jan/2004
   */
  public abstract class ApplicationCommand implements Command {
  	
  	static Logger logger = Logger.getLogger(ApplicationCommand.class.getName());
  	
  	SessionManager sessionManager;
  
      /***
       * 
       */
      public ApplicationCommand() {
          super();
      }
  
  	public Object execute(Object arg) {
  		return execute((ApplicationMessage)arg);
  	}
  	
      /* (non-Javadoc)
       * @see replica.command.Command#execute(java.lang.Object)
       */
      protected abstract Object execute(ApplicationMessage arg);
  
      /***
       * @return
       */
      public SessionManager getSessionManager() {
          return sessionManager;
      }
  
      /***
       * @param manager
       */
      public void setSessionManager(SessionManager manager) {
          sessionManager = manager;
      }
  
      /***
       * @return
       */
      protected static Logger getLogger() {
          return logger;
      }
      
      protected ServerProcess getServerProcess( String sessionId ){
      	
      	Session session = getSessionManager().getSession(sessionId);
      	if( session != null )
      		return (ServerProcess)session.getObject("SERVER_PROCESS");
      	
      	logger.warning("Server Process found for session with id : [" + sessionId + "].");
      	return null; 
      }
  
  }