1 | /* |
2 | Copyright (C) 2004 MySQL AB |
3 | |
4 | This program is free software; you can redistribute it and/or modify |
5 | it under the terms of the GNU General Public License version 2 as |
6 | published by the Free Software Foundation. |
7 | |
8 | This program is distributed in the hope that it will be useful, |
9 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
10 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
11 | GNU General Public License for more details. |
12 | |
13 | You should have received a copy of the GNU General Public License |
14 | along with this program; if not, write to the Free Software |
15 | Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
16 | |
17 | */ |
18 | package com.mysql.management.util; |
19 | |
20 | import java.util.ArrayList; |
21 | import java.util.Collection; |
22 | import java.util.HashMap; |
23 | import java.util.Iterator; |
24 | import java.util.LinkedHashMap; |
25 | import java.util.LinkedHashSet; |
26 | import java.util.List; |
27 | import java.util.Map; |
28 | import java.util.Set; |
29 | |
30 | /** |
31 | * Map which retains the first value a key is set to as a "default" until the |
32 | * key is removed |
33 | * |
34 | * This class is final simply as a hint to the compiler, it may be un-finalized |
35 | * safely. |
36 | * |
37 | * @author Eric Herman <eric@mysql.com> |
38 | * @version $Id: DefaultsMap.java,v 1.4 2005/07/27 23:41:27 eherman Exp $ |
39 | */ |
40 | public final class DefaultsMap implements Map { |
41 | |
42 | private Map changed; |
43 | |
44 | private Map original; |
45 | |
46 | private Equals equals; |
47 | |
48 | public DefaultsMap() { |
49 | this.original = new LinkedHashMap(); |
50 | this.changed = new LinkedHashMap(); |
51 | this.equals = new Equals(); |
52 | } |
53 | |
54 | public Map getChanged() { |
55 | return new HashMap(changed); |
56 | } |
57 | |
58 | public Object getDefault(Object key) { |
59 | return original.get(key); |
60 | } |
61 | |
62 | public void clear() { |
63 | changed.clear(); |
64 | original.clear(); |
65 | } |
66 | |
67 | public boolean containsKey(Object key) { |
68 | return original.containsKey(key); |
69 | } |
70 | |
71 | public boolean containsValue(Object value) { |
72 | for (Iterator iter = keySet().iterator(); iter.hasNext();) { |
73 | Object val = get(iter.next()); |
74 | if (value == null) { |
75 | if (val == null) { |
76 | return true; |
77 | } |
78 | } else { |
79 | if (value.equals(val)) { |
80 | return true; |
81 | } |
82 | } |
83 | } |
84 | return false; |
85 | } |
86 | |
87 | public Set entrySet() { |
88 | Set entries = new LinkedHashSet(); |
89 | for (Iterator iter = keySet().iterator(); iter.hasNext();) { |
90 | Object key = iter.next(); |
91 | entries.add(new MapEntry(key, get(key))); |
92 | } |
93 | return entries; |
94 | } |
95 | |
96 | public Object get(Object key) { |
97 | if (changed.containsKey(key)) { |
98 | return changed.get(key); |
99 | } |
100 | return original.get(key); |
101 | } |
102 | |
103 | public boolean isEmpty() { |
104 | return original.size() == 0; |
105 | } |
106 | |
107 | public Set keySet() { |
108 | return original.keySet(); |
109 | } |
110 | |
111 | public Object put(Object key, Object value) { |
112 | if (!original.containsKey(key)) { |
113 | return original.put(key, value); |
114 | } |
115 | Object originalVal = original.get(key); |
116 | if (!equals.nullSafe(originalVal, value)) { |
117 | return changed.put(key, value); |
118 | } |
119 | if (changed.containsKey(key)) { |
120 | return changed.remove(key); |
121 | } |
122 | return original.put(key, value); |
123 | } |
124 | |
125 | public void putAll(Map t) { |
126 | for (Iterator iter = t.entrySet().iterator(); iter.hasNext();) { |
127 | Map.Entry entry = (Map.Entry) iter.next(); |
128 | put(entry.getKey(), entry.getValue()); |
129 | } |
130 | } |
131 | |
132 | public Object remove(Object key) { |
133 | Object oldVal = original.remove(key); |
134 | if (changed.containsKey(key)) { |
135 | return changed.remove(key); |
136 | } |
137 | return oldVal; |
138 | } |
139 | |
140 | public int size() { |
141 | return original.size(); |
142 | } |
143 | |
144 | public Collection values() { |
145 | List values = new ArrayList(original.size()); |
146 | for (Iterator iter = keySet().iterator(); iter.hasNext();) { |
147 | values.add(get(iter.next())); |
148 | } |
149 | return values; |
150 | } |
151 | } |