| 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 | } |