1/*
2 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package java.rmi.activation;
27
28import java.rmi.server.UID;
29
30/**
31 * The identifier for a registered activation group serves several
32 * purposes: <ul>
33 * <li>identifies the group uniquely within the activation system, and
34 * <li>contains a reference to the group's activation system so that the
35 * group can contact its activation system when necessary.</ul><p>
36 *
37 * The <code>ActivationGroupID</code> is returned from the call to
38 * <code>ActivationSystem.registerGroup</code> and is used to identify
39 * the group within the activation system. This group id is passed
40 * as one of the arguments to the activation group's special constructor
41 * when an activation group is created/recreated.
42 *
43 * @author      Ann Wollrath
44 * @see         ActivationGroup
45 * @see         ActivationGroupDesc
46 * @since       1.2
47 */
48public class ActivationGroupID implements java.io.Serializable {
49    /**
50     * @serial The group's activation system.
51     */
52    private ActivationSystem system;
53
54    /**
55     * @serial The group's unique id.
56     */
57    private UID uid = new UID();
58
59    /** indicate compatibility with the Java 2 SDK v1.2 version of class */
60    private  static final long serialVersionUID = -1648432278909740833L;
61
62    /**
63     * Constructs a unique group id.
64     *
65     * @param system the group's activation system
66     * @throws UnsupportedOperationException if and only if activation is
67     *         not supported by this implementation
68     * @since 1.2
69     */
70    public ActivationGroupID(ActivationSystem system) {
71        this.system = system;
72    }
73
74    /**
75     * Returns the group's activation system.
76     * @return the group's activation system
77     * @since 1.2
78     */
79    public ActivationSystem getSystem() {
80        return system;
81    }
82
83    /**
84     * Returns a hashcode for the group's identifier.  Two group
85     * identifiers that refer to the same remote group will have the
86     * same hash code.
87     *
88     * @see java.util.Hashtable
89     * @since 1.2
90     */
91    public int hashCode() {
92        return uid.hashCode();
93    }
94
95    /**
96     * Compares two group identifiers for content equality.
97     * Returns true if both of the following conditions are true:
98     * 1) the unique identifiers are equivalent (by content), and
99     * 2) the activation system specified in each
100     *    refers to the same remote object.
101     *
102     * @param   obj     the Object to compare with
103     * @return  true if these Objects are equal; false otherwise.
104     * @see             java.util.Hashtable
105     * @since 1.2
106     */
107    public boolean equals(Object obj) {
108        if (this == obj) {
109            return true;
110        } else if (obj instanceof ActivationGroupID) {
111            ActivationGroupID id = (ActivationGroupID)obj;
112            return (uid.equals(id.uid) && system.equals(id.system));
113        } else {
114            return false;
115        }
116    }
117}
118