1 /*
2 * Copyright (c) 2003, Henri Yandell
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or
6 * without modification, are permitted provided that the
7 * following conditions are met:
8 *
9 * + Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 *
12 * + Redistributions in binary form must reproduce the above copyright notice,
13 * this list of conditions and the following disclaimer in the documentation
14 * and/or other materials provided with the distribution.
15 *
16 * + Neither the name of Genjava-Core nor the names of its contributors
17 * may be used to endorse or promote products derived from this software
18 * without specific prior written permission.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
24 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
27 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
28 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30 * POSSIBILITY OF SUCH DAMAGE.
31 */
32 package com.generationjava.collections;
33
34 import java.util.Map;
35 import org.apache.commons.collections.ProxyMap;
36
37 /***
38 * A map which stores objects by a key Class.
39 * When obtaining the object, it will check inheritence and
40 * interface trees to see if the Class matches.
41 */
42 public class ClassMap extends ProxyMap {
43
44 public ClassMap(Map m) {
45 super(m);
46 }
47
48 /***
49 * Get the object from the map. If the key is not
50 * a Class object, then it uses the Class of the object.
51 */
52 public Object get(Object key) {
53 if(key == null) {
54 return null;
55 }
56 Class clss = null;
57
58 if(key instanceof Class) {
59 clss = (Class)key;
60 } else {
61 clss = key.getClass();
62 }
63
64 Object obj = super.get(clss);
65
66 if(obj == null) {
67
68 // if this is null, let's go up the inheritence tree
69 obj = getInterfaces(clss);
70
71 if(obj == null) {
72 obj = getSuperclass(clss);
73 }
74 }
75
76 return obj;
77 }
78
79 private Object getInterfaces(Class clss) {
80 if(clss == null) {
81 return null;
82 }
83 Object obj = null;
84 Class[] interfaces = clss.getInterfaces();
85 for(int i=0; i<interfaces.length; i++) {
86 obj = (Object)super.get(interfaces[i]);
87 if(obj != null) {
88 return obj;
89 }
90 obj = getInterfaces(interfaces[i]);
91 if(obj != null) {
92 return obj;
93 }
94 obj = getSuperclass(interfaces[i]);
95 if(obj != null) {
96 return obj;
97 }
98 }
99 return null;
100 }
101
102 private Object getSuperclass(Class clss) {
103 if(clss == null) {
104 return null;
105 }
106 Object obj = null;
107 Class superclass = clss.getSuperclass();
108 obj = (Object)super.get(superclass);
109 if(obj != null) {
110 return obj;
111 }
112 obj = getInterfaces(superclass);
113 if(obj != null) {
114 return obj;
115 }
116 obj = getSuperclass(superclass);
117 if(obj != null) {
118 return obj;
119 }
120 return null;
121 }
122
123 }