Participant.java

/*
 * JBoss, Home of Professional Open Source
 * Copyright 2006, Red Hat Middleware LLC, and individual contributors
 * as indicated by the @author tags. 
 * See the copyright.txt in the distribution for a full listing 
 * of individual contributors.
 * This copyrighted material is made available to anyone wishing to use,
 * modify, copy, or redistribute it subject to the terms and conditions
 * of the GNU Lesser General Public License, v. 2.1.
 * This program is distributed in the hope that it will be useful, but WITHOUT A
 * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
 * You should have received a copy of the GNU Lesser General Public License,
 * v.2.1 along with this distribution; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA  02110-1301, USA.
 * 
 * (C) 2005-2006,
 * @author JBoss Inc.
 */
package com.arjuna.wst;

import com.arjuna.wst.SystemException;
import com.arjuna.wst.Vote;
import com.arjuna.wst.WrongStateException;

/**
 * The base Participant.
 */
public interface Participant
{

    /**
     * Perform any work necessary to allow it to either commit or rollback
     * the work performed by the Web service under the scope of the
     * transaction. The implementation is free to do whatever it needs to in
     * order to fulfill the implicit contract between it and the coordinator.
     *
     * @return an indication of whether it can prepare or not.
     * @see com.arjuna.wst.Vote
     */

    public Vote prepare () throws WrongStateException, SystemException;

    /**
     * The participant should make permanent the work that it controls.
     */

    public void commit () throws WrongStateException, SystemException;

    /**
     * The participant should undo the work that it controls. The participant
     * will then return an indication of whether or not it succeeded.
     */

    public void rollback () throws WrongStateException, SystemException;

    /**
     * During recovery the participant can enquire as to the status of the
     * transaction it was registered with. If that transaction is no longer
     * available (has rolled back) then this operation will be invoked by the
     * coordination service.
     */

    public void unknown () throws SystemException;

    /**
     * During recovery the participant can enquire as to the status of the
     * transaction it was registered with. If an error occurs (e.g., the
     * transaction service is unavailable) then this operation will be invoked.
     */
    
    void error () throws SystemException;
    
}