org.ow2.cmi.lb.decision.BasicDecisionManager Maven / Gradle / Ivy

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/**
 * Copyright (C) 2007-2008 Bull S.A.S.
 *
 * CMI : Cluster Method Invocation
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 * USA
 *
 * --------------------------------------------------------------------------
 * $Id: BasicDecisionManager.java 1811 2008-05-30 16:16:32Z loris $
 * --------------------------------------------------------------------------
 */
package org.ow2.cmi.lb.decision;

import net.jcip.annotations.Immutable;

/**
 * Encapsulates a decision and an eventually returned value.
 * @param  the type of the returned value (can be {@link Void})
 * @author The new CMI team
 */
@Immutable
public final class BasicDecisionManager implements DecisionManager {

    /**
     * Chosen Decision.
     */
    private final Decision decision;

    /**
     * Value associated with return decision.
     */
    private final ReturnType retVal;

    /**
     * An exception to throw.
     */
    private final Throwable throwable;

    /**
     * Creates a RETRY decision.
     */
    private BasicDecisionManager() {
        this.decision = Decision.RETRY;
        this.retVal = null;
        this.throwable = null;
    }

    /**
     * Creates a RETURN decision.
     * @param retVal the value to return
     */
    private BasicDecisionManager(final ReturnType retVal) {
        this.decision = Decision.RETURN;
        this.retVal = retVal;
        this.throwable = null;
    }

    /**
     * Creates a THROW decision.
     * @param decision value of the decision
     */
    private BasicDecisionManager(final Throwable throwable) {
        this.decision = Decision.THROW;
        this.retVal = null;
        this.throwable = throwable;
    }

    /**
     * Creates a RETRY decision.
     * @return RETRY
     */
    public static BasicDecisionManager doRetry() {
        return new BasicDecisionManager();
    }

    /**
     * Creates a THROW decision.
     * @param throwable an exception to throw
     * @return THROW
     */
    public static BasicDecisionManager doThrow(final Throwable throwable) {
        return new BasicDecisionManager(throwable);
    }

    /**
     * Creates a RETURN decision.
     * @param retVal the value to return
     * @return RETURN
     * @param  the type of the returned value (can be {@link Void})
     */
    public static  BasicDecisionManager doReturn(final ReturnType retVal) {
        return new BasicDecisionManager(retVal);
    }

    /**
     * @return the decision
     */
    public Decision getDecision() {
        return decision;
    }

    /**
     * @return the returned value
     */
    public ReturnType getRetVal() {
        return retVal;
    }

    /**
     * @return an exception to throw
     */
    public Throwable getThrowable() {
        return throwable;
    }
}