org.jboss.ejb.client.EJBReceiverInvocationContext Maven / Gradle / Ivy

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/*
 * JBoss, Home of Professional Open Source.
 * Copyright 2011, Red Hat, Inc., and individual contributors
 * as indicated by the @author tags. See the copyright.txt file in the
 * distribution for a full listing of individual contributors.
 *
 * This 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 (at your option) any later version.
 *
 * This software 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 software; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
 */

package org.jboss.ejb.client;

/**
 * The context used for an EJB receiver to return the result of an invocation.
 *
 * @author David M. Lloyd
 */
public final class EJBReceiverInvocationContext {
    private final EJBClientInvocationContext clientInvocationContext;
    private final EJBReceiverContext ejbReceiverContext;

    EJBReceiverInvocationContext(final EJBClientInvocationContext clientInvocationContext, final EJBReceiverContext ejbReceiverContext) {
        this.clientInvocationContext = clientInvocationContext;
        this.ejbReceiverContext = ejbReceiverContext;
    }

    /**
     * Get the associated EJB receiver context.
     *
     * @return the EJB receiver context
     */
    public EJBReceiverContext getEjbReceiverContext() {
        return ejbReceiverContext;
    }

    /**
     * Returns the {@link EJBClientInvocationContext} associated with this EJB receiver invocation context
     *
     * @return
     */
    public EJBClientInvocationContext getClientInvocationContext() {
        return this.clientInvocationContext;
    }

    /**
     * Indicate that the invocation should proceed asynchronously, if it isn't already.
     */
    public void proceedAsynchronously() {
        clientInvocationContext.proceedAsynchronously();
    }

    /**
     * Indicate that the invocation result is ready.  The given producer should either return the final
     * invocation result or throw an appropriate exception.  Any unmarshalling is expected to be deferred until
     * the result producer is called, in order to offload the work on the invoking thread even in the presence of
     * asynchronous invocation.
     *
     * @param resultProducer the result producer
     */
    public void resultReady(ResultProducer resultProducer) {
        clientInvocationContext.resultReady(resultProducer);
    }

    /**
     * Indicate that the request was successfully cancelled and that no result is forthcoming.
     */
    public void requestCancelled() {
        clientInvocationContext.cancelled();
    }

    /**
     * Retry the current invocation
     *
     * @param excludeCurrentReceiver True if the {@link EJBReceiver} represented by this {@link EJBReceiverInvocationContext}
     *                               has to be excluded from being chosen for handling the retried invocation. False otherwise.
     * @throws Exception If the retried invocation runs into any exception
     */
    public void retryInvocation(final boolean excludeCurrentReceiver) throws Exception {
        if (excludeCurrentReceiver) {
            final EJBReceiver currentReceiver = this.ejbReceiverContext.getReceiver();
            this.clientInvocationContext.markNodeAsExcluded(currentReceiver.getNodeName());
        }
        this.clientInvocationContext.retryRequest();
    }

    /**
     * Returns the node name of the receiver represented by this {@link EJBReceiverInvocationContext}
     *
     * @return
     */
    public String getNodeName() {
        return this.ejbReceiverContext.getReceiver().getNodeName();
    }

    /**
     * A result producer for invocation.
     */
    public interface ResultProducer {

        /**
         * Get the result.
         *
         * @return the result
         * @throws Exception if the result could not be acquired or the operation failed
         */
        Object getResult() throws Exception;

        /**
         * Discard the result, indicating that it will not be used.
         */
        void discardResult();
    }

}