HighLevelObject.java

/*
** Module   : HighLevelObject.java
** Abstract : base class for remote objects
**
** Copyright (c) 2005-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- --JPRM-- ----------------Description-----------------
** 001 SIY 20050201   @19495 Created an initial version with three helper
**                           methods (getKey, transact and forward) which
**                           don't need to be replaced.
**                           Application may replace getTimeout() to
**                           provide different or configurable timeout.
** 002 SIY 20050315   @20381 Fixed spelling and other minor cleanups.
** 003 SIY 20050329   @20544 Fixed comments.
** 004 SIY 20050505   @21110 Changed visibility of getTimeout() method.
** 005 NVS 20060704   @27789 getKey() now throws an exception instead of
**                           silently returning a null RoutingKey.
** 006 GES 20070115   @31832 Cleanup of code/formatting. The interface is
**                           now public since this class does nothing that
**                           can't already be done via the public Queue
**                           interface.  Matched a minor method name 
**                           change in Queue.  Moved the timeout to a
**                           member rather than forcing subclasses to
**                           override the method.
** 007 ECF 20071106   @35881 Replaced Queue with Session.
** 008 SIY 20090831   @43797 Added handling of null routing keys and check
**                           for possible causes of exceptions when 
**                           obtaining routing keys.
** 009 HC  20230427          Added logging.
** 010 GBB 20230512          Logging methods replaced by CentralLogger/ConversionStatus.
*/
/*
** This program is free software: you can redistribute it and/or modify
** it under the terms of the GNU Affero General Public License as
** published by the Free Software Foundation, either version 3 of the
** License, or (at your option) any later version.
**
** This program is distributed in the hope that it will be useful,
** but WITHOUT ANY WARRANTY; without even the implied warranty of
** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
** GNU Affero General Public License for more details.
**
** You may find a copy of the GNU Affero GPL version 3 at the following
** location: https://www.gnu.org/licenses/agpl-3.0.en.html
** 
** Additional terms under GNU Affero GPL version 3 section 7:
** 
**   Under Section 7 of the GNU Affero GPL version 3, the following additional
**   terms apply to the works covered under the License.  These additional terms
**   are non-permissive additional terms allowed under Section 7 of the GNU
**   Affero GPL version 3 and may not be removed by you.
** 
**   0. Attribution Requirement.
** 
**     You must preserve all legal notices or author attributions in the covered
**     work or Appropriate Legal Notices displayed by works containing the covered
**     work.  You may not remove from the covered work any author or developer
**     credit already included within the covered work.
** 
**   1. No License To Use Trademarks.
** 
**     This license does not grant any license or rights to use the trademarks
**     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
**     of Golden Code Development Corporation. You are not authorized to use the
**     name Golden Code, FWD, or the names of any author or contributor, for
**     publicity purposes without written authorization.
** 
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** 
**     You may not represent yourself as Golden Code Development Corporation or FWD.
** 
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**     Golden Code Development Corporation, FWD, or any author or contributor to
**     the covered work, without written authorization.
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**     versions of the covered work must be marked in a reasonable way to make it
**     clear that the modified work is not originating from Golden Code Development
**     Corporation or FWD.  All modified versions must contain the notices of
**     attribution required in this license.
*/

package com.goldencode.p2j.net;

import com.goldencode.p2j.util.logging.*;

import java.util.logging.*;

/**
 * Base class for remote objects which provides some useful utility methods.
 */
public class HighLevelObject
{
   /** Logger */
   private static CentralLogger LOG = CentralLogger.get(HighLevelObject.class);

   /** Session which represents connection. */
   protected Session session;
   
   /** The timeout for synchronous calls. */
   private int timeout = 10000;

   /**
    * Constructs an instance using the given transport.
    * 
    * @param    session
    *           Session with properly initialized transport.
    */
   public HighLevelObject(Session session)
   {
      this.session = session;
   }

   /**
    * Constructs an instance using the given transport and timeout.
    * 
    * @param    session
    *           Session with properly initialized transport.
    * @param    timeout
    *           The transaction timeout in milliseconds.
    */
   public HighLevelObject(Session session, int timeout)
   {
      this.session = session;
      this.timeout = timeout;
   }

   /**
    * Get the transaction timeout in milliseconds.
    * 
    * @return   The timeout in milliseconds.
    */
   public int getTimeout()
   {
      return timeout;
   }
   
   /**
    * Set the transaction timeout in milliseconds.
    * 
    * @param    timeout
    *           The timeout in milliseconds.
    */
   public void setTimeout(int timeout)
   {
      this.timeout = timeout;
   }
   
   /**
    * Get the routing key instance that represents the given group and method
    * at the remote side of the session.
    * 
    * @param    group
    *           Group name.
    * @param    method
    *           Method name.
    *
    * @return   The instance of the routing key which corresponds to given
    *           the group and method.
    *
    * @throws   Exception
    *           If any problem happens during processing of the request.
    */
   public RoutingKey getKey(String group, String method)
   throws Exception
   {
      try
      {
         Object[] parms = new Object[] {group, method};
         
         RoutingKey key = (RoutingKey) transact(new RoutingKey(), parms);
      
         if (key == null)
         {
            String err = "No export or no access to " + group + ":" + method;
            throw new RuntimeException(err);
         }
         
         return key;
      }
      catch (IllegalStateException ise)
      {
         LOG.log(Level.SEVERE, "Failed to obtain routing key", ise);
         return null;         
      }
   }

   /**
    * Convenience wrapper for {@link Queue#forward}.
    * 
    * @param    key
    *           An instance of RoutingKey which points to method to call at
    *           remote side.
    * @param    parms
    *           Method parameters.
    */
   public void forward(RoutingKey key, Object[] parms)
   {
      session.forward(new Message(key, parms));
   }

   /**
    * Convenience wrapper for {@link Queue#transact}.
    * 
    * @param    key
    *           The routing key which represents the method to call at the
    *           remote side.
    * @param    parms
    *           Method parameters.
    *
    * @return   The transaction result.
    *
    * @throws   Exception
    *           If any problem occurs during {@link Queue#transact}.
    */
   public Object transact(RoutingKey key, Object[] parms)
   throws Exception
   {
      return session.transact(new Message(key, parms), timeout);
   }
}