/*

 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code 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 General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package java.rmi.activation;

import java.rmi.server.UID;

/**

 * The identifier for a registered activation group serves several

 * purposes: <ul>

 * <li>identifies the group uniquely within the activation system, and

 * <li>contains a reference to the group's activation system so that the

 * group can contact its activation system when necessary.</ul><p>

 *

 * The <code>ActivationGroupID</code> is returned from the call to

 * <code>ActivationSystem.registerGroup</code> and is used to identify

 * the group within the activation system. This group id is passed

 * as one of the arguments to the activation group's special constructor

 * when an activation group is created/recreated.

 *

 * @author      Ann Wollrath

 * @see         ActivationGroup

 * @see         ActivationGroupDesc

 * @since       1.2

 */

public class ActivationGroupID implements java.io.Serializable {

    /**

     * @serial The group's activation system.

     */

    private ActivationSystem system;

    /**

     * @serial The group's unique id.

     */

    private UID uid = new UID();

    /** indicate compatibility with the Java 2 SDK v1.2 version of class */

    private  static final long serialVersionUID = -1648432278909740833L;

    /**

     * Constructs a unique group id.

     *

     * @param system the group's activation system

     * @throws UnsupportedOperationException if and only if activation is

     *         not supported by this implementation

     * @since 1.2

     */

    public ActivationGroupID(ActivationSystem system) {

        this.system = system;

    }

    /**

     * Returns the group's activation system.

     * @return the group's activation system

     * @since 1.2

     */

    public ActivationSystem getSystem() {

        return system;

    }

    /**

     * Returns a hashcode for the group's identifier.  Two group

     * identifiers that refer to the same remote group will have the

     * same hash code.

     *

     * @see java.util.Hashtable

     * @since 1.2

     */

    public int hashCode() {

        return uid.hashCode();

    }

    /**

     * Compares two group identifiers for content equality.

     * Returns true if both of the following conditions are true:

     * 1) the unique identifiers are equivalent (by content), and

     * 2) the activation system specified in each

     *    refers to the same remote object.

     *

     * @param   obj     the Object to compare with

     * @return  true if these Objects are equal; false otherwise.

     * @see             java.util.Hashtable

     * @since 1.2

     */

    public boolean equals(Object obj) {

        if (this == obj) {

            return true;

        } else if (obj instanceof ActivationGroupID) {

            ActivationGroupID id = (ActivationGroupID)obj;

            return (uid.equals(id.uid) && system.equals(id.system));

        } else {

            return false;

        }

    }

}