1/*
2 * Copyright 2009 Mike Cumings
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *   http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 package com.kenai.jbosh;
18
19/**
20 * Abstract base class for creating BOSH attribute classes.  Concrete
21 * implementations of this class will naturally inherit the underlying
22 * type's behavior for {@code equals()}, {@code hashCode()},
23 * {@code toString()}, and {@code compareTo()}, allowing for the easy
24 * creation of objects which extend existing trivial types.  This was done
25 * to comply with the prefactoring rule declaring, "when you are being
26 * abstract, be abstract all the way".
27 *
28 * @param <T> type of the extension object
29 */
30abstract class AbstractAttr<T extends Comparable>
31    implements Comparable {
32
33    /**
34     * Captured value.
35     */
36    private final T value;
37
38    /**
39     * Creates a new encapsulated object instance.
40     *
41     * @param aValue encapsulated getValue
42     */
43    protected AbstractAttr(final T aValue) {
44        value = aValue;
45    }
46
47    /**
48     * Gets the encapsulated data value.
49     *
50     * @return data value
51     */
52    public final T getValue() {
53        return value;
54    }
55
56    ///////////////////////////////////////////////////////////////////////////
57    // Object method overrides:
58
59    /**
60     * {@inheritDoc}
61     *
62     * @param otherObj object to compare to
63     * @return true if the objects are equal, false otherwise
64     */
65    @Override
66    public boolean equals(final Object otherObj) {
67        if (otherObj == null) {
68            return false;
69        } else if (otherObj instanceof AbstractAttr) {
70            AbstractAttr other =
71                    (AbstractAttr) otherObj;
72            return value.equals(other.value);
73        } else {
74            return false;
75        }
76    }
77
78    /**
79     * {@inheritDoc}
80     *
81     * @return hashCode of the encapsulated object
82     */
83    @Override
84    public int hashCode() {
85        return value.hashCode();
86    }
87
88    /**
89     * {@inheritDoc}
90     *
91     * @return string representation of the encapsulated object
92     */
93    @Override
94    public String toString() {
95        return value.toString();
96    }
97
98    ///////////////////////////////////////////////////////////////////////////
99    // Comparable interface:
100
101    /**
102     * {@inheritDoc}
103     *
104     * @param otherObj object to compare to
105     * @return -1, 0, or 1
106     */
107    @SuppressWarnings("unchecked")
108    public int compareTo(final Object otherObj) {
109        if (otherObj == null) {
110            return 1;
111        } else {
112            return value.compareTo(otherObj);
113        }
114    }
115
116}
117