001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions Copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2012-2015 ForgeRock AS.
015 */
016
017package org.forgerock.json.resource;
018
019import java.io.Closeable;
020
021import org.forgerock.util.promise.Promise;
022
023/**
024 * A connection factory provides an interface for obtaining a connection to a
025 * JSON resource provider. Connection factories can be used to wrap other
026 * connection factories in order to provide enhanced capabilities in a manner
027 * which is transparent to the application. For example:
028 * <ul>
029 * <li>Connection pooling
030 * <li>Load balancing
031 * <li>Keep alive
032 * <li>Logging connections
033 * <li>Read-only connections
034 * </ul>
035 * An application typically obtains a connection from a connection factory,
036 * performs one or more operations, and then closes the connection. Applications
037 * should aim to close connections as soon as possible in order to avoid
038 * resource contention.
039 */
040public interface ConnectionFactory extends Closeable {
041
042    /**
043     * Releases any resources associated with this connection factory. Depending
044     * on the implementation a factory may:
045     * <ul>
046     * <li>do nothing
047     * <li>close underlying connection factories (e.g. load-balancers)
048     * <li>close pooled connections (e.g. connection pools)
049     * <li>shutdown IO event service and related thread pools (e.g. Grizzly).
050     * </ul>
051     * Calling {@code close} on a connection factory which is already closed has
052     * no effect.
053     * <p>
054     * Applications should avoid closing connection factories while there are
055     * remaining active connections in use or connection attempts in progress.
056     *
057     * @see Resources#uncloseable(ConnectionFactory)
058     */
059    @Override
060    void close();
061
062    /**
063     * Returns a connection to the JSON resource provider associated with this
064     * connection factory. The connection returned by this method can be used
065     * immediately.
066     *
067     * @return A connection to the JSON resource provider associated with this
068     *         connection factory.
069     * @throws ResourceException
070     *             If the connection request failed for some reason.
071     */
072    Connection getConnection() throws ResourceException;
073
074    /**
075     * Asynchronously obtains a connection to the JSON resource provider
076     * associated with this connection factory. The returned
077     * {@code FutureResult} can be used to retrieve the completed connection.
078     *
079     * @return A future which can be used to retrieve the connection.
080     */
081    Promise<Connection, ResourceException> getConnectionAsync();
082}