SyncMessage.java
/*
** Module : SyncMessage.java
** Abstract : state synchronization extensions to a standard message
**
** Copyright (c) 2006-2023, Golden Code Development Corporation.
**
** -#- -I- --Date-- --JPRM-- ----------------------------------Description------------------------------------
** 001 GES 20060726 @28197 Created initial version with state synchronization extensions to a standard
** message.
** 002 GES 20060731 @28257 Removed extraneous call to the parent's readObject/writeObject methods since the
** Java infrastructure does this for us.
** 003 GES 20060801 @28290 Converted to Externalizable to improve efficiency because Serializable has
** unneeded processing (for versioning...) that is executed on "inflation".
** 004 CA 20200923 Changed StateSynchronizer to return Externalizable instances.
** CA 20200930 Used PayloadSerializer to write the state instance.
** 005 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.
**
** 2. No Misrepresentation of Affiliation.
**
** 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.
**
** 3. No Misrepresentation of Source or Origin.
**
** You may not represent the covered work as solely your work. All modified
** 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 java.io.*;
import com.goldencode.util.*;
/**
* This class provides state synchronization extensions to a standard
* message. In particular, there is an additional "payload" that is
* provided to allow any state changes that need to be synchronized to be
* "piggybacked" into any existing message.
*
* @author GES
*/
public class SyncMessage
extends Message
{
/** State to be synchronized. */
private Externalizable state = null;
/**
* Default constructor, used during de-serialization.
*/
public SyncMessage()
{
}
/**
* Constructs an instance using an already existing message.
*
* @param msg
* A valid message. Must not be <code>null</code>.
* @param state
* The state to be piggybacked into the given message.
*/
public SyncMessage(Message msg, Externalizable state)
{
super(msg);
this.state = state;
}
/**
* Get the state from the message.
*
* @return The state carried in this message.
*/
public Externalizable getState()
{
return state;
}
/**
* Set the state in the message.
*
* @param state
* The state to be carried in this message.
*/
public void setState(Externalizable state)
{
this.state = state;
}
/**
* Replacement for the default object reading method. The piggybacked
* state is read from the input source. Note that the parent's version of
* this method is called first because as an <code>Externalizable</code>
* it won't be called by the serialization infrastructure.
*
* @param in
* Input source from which fields will be restored.
*
* @throws IOException
* In case of I/O errors.
* @throws ClassNotFoundException
* If payload can't be instantiated.
*/
public void readExternal(ObjectInput in)
throws IOException,
ClassNotFoundException
{
super.readExternal(in);
state = (Externalizable) PayloadSerializer.readPayload(in);
// LOG.finer("Deserialized: %s\n", state == null ? "null" : state.getClass().getName());
}
/**
* Replacement for the default object writing method. The piggybacked
* state is written to the output source. Note that the parent's version of
* this method is called first because as an <code>Externalizable</code>
* it won't be called by the serialization infrastructure.
*
* @param out
* The output destination to which fields will be saved.
*
* @throws IOException
* In case of I/O errors.
*/
public void writeExternal(ObjectOutput out)
throws IOException
{
super.writeExternal(out);
// LOG.finer("Serializing: %s\n", state == null ? "null" : state.getClass().getName());
PayloadSerializer.writePayload(out, state);
}
}