author | ohair |
Wed, 06 Apr 2011 22:06:11 -0700 | |
changeset 9035 | 1255eb81cc2f |
parent 7803 | 56bc97d69d93 |
child 9275 | 1df1f7dfab7f |
permissions | -rw-r--r-- |
2 | 1 |
/* |
9035
1255eb81cc2f
7033660: Update copyright year to 2011 on any files changed in 2011
ohair
parents:
7803
diff
changeset
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* Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved. |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. Oracle designates this |
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* particular file as subject to the "Classpath" exception as provided |
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* by Oracle in the LICENSE file that accompanied this code. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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package java.util; |
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import java.util.Map.Entry; |
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import sun.misc.SharedSecrets; |
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/** |
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* A specialized {@link Map} implementation for use with enum type keys. All |
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* of the keys in an enum map must come from a single enum type that is |
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* specified, explicitly or implicitly, when the map is created. Enum maps |
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* are represented internally as arrays. This representation is extremely |
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* compact and efficient. |
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* |
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* <p>Enum maps are maintained in the <i>natural order</i> of their keys |
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* (the order in which the enum constants are declared). This is reflected |
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* in the iterators returned by the collections views ({@link #keySet()}, |
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* {@link #entrySet()}, and {@link #values()}). |
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* |
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* <p>Iterators returned by the collection views are <i>weakly consistent</i>: |
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* they will never throw {@link ConcurrentModificationException} and they may |
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* or may not show the effects of any modifications to the map that occur while |
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* the iteration is in progress. |
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* |
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* <p>Null keys are not permitted. Attempts to insert a null key will |
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* throw {@link NullPointerException}. Attempts to test for the |
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* presence of a null key or to remove one will, however, function properly. |
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* Null values are permitted. |
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* <P>Like most collection implementations <tt>EnumMap</tt> is not |
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* synchronized. If multiple threads access an enum map concurrently, and at |
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* least one of the threads modifies the map, it should be synchronized |
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* externally. This is typically accomplished by synchronizing on some |
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* object that naturally encapsulates the enum map. If no such object exists, |
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* the map should be "wrapped" using the {@link Collections#synchronizedMap} |
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* method. This is best done at creation time, to prevent accidental |
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* unsynchronized access: |
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* |
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* <pre> |
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* Map<EnumKey, V> m |
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* = Collections.synchronizedMap(new EnumMap<EnumKey, V>(...)); |
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* </pre> |
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* |
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* <p>Implementation note: All basic operations execute in constant time. |
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* They are likely (though not guaranteed) to be faster than their |
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* {@link HashMap} counterparts. |
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* |
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* <p>This class is a member of the |
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* <a href="{@docRoot}/../technotes/guides/collections/index.html"> |
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* Java Collections Framework</a>. |
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* |
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* @author Josh Bloch |
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* @see EnumSet |
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* @since 1.5 |
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*/ |
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public class EnumMap<K extends Enum<K>, V> extends AbstractMap<K, V> |
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implements java.io.Serializable, Cloneable |
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{ |
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/** |
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* The <tt>Class</tt> object for the enum type of all the keys of this map. |
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* |
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* @serial |
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*/ |
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private final Class<K> keyType; |
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/** |
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* All of the values comprising K. (Cached for performance.) |
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*/ |
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private transient K[] keyUniverse; |
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/** |
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* Array representation of this map. The ith element is the value |
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* to which universe[i] is currently mapped, or null if it isn't |
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* mapped to anything, or NULL if it's mapped to null. |
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*/ |
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private transient Object[] vals; |
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/** |
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* The number of mappings in this map. |
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*/ |
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private transient int size = 0; |
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/** |
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* Distinguished non-null value for representing null values. |
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*/ |
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private static final Object NULL = new Object(); |
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private Object maskNull(Object value) { |
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return (value == null ? NULL : value); |
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} |
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private V unmaskNull(Object value) { |
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return (V) (value == NULL ? null : value); |
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} |
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private static Enum[] ZERO_LENGTH_ENUM_ARRAY = new Enum[0]; |
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/** |
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* Creates an empty enum map with the specified key type. |
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* |
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* @param keyType the class object of the key type for this enum map |
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* @throws NullPointerException if <tt>keyType</tt> is null |
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*/ |
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public EnumMap(Class<K> keyType) { |
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this.keyType = keyType; |
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keyUniverse = getKeyUniverse(keyType); |
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vals = new Object[keyUniverse.length]; |
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} |
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/** |
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* Creates an enum map with the same key type as the specified enum |
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* map, initially containing the same mappings (if any). |
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* |
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* @param m the enum map from which to initialize this enum map |
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* @throws NullPointerException if <tt>m</tt> is null |
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*/ |
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public EnumMap(EnumMap<K, ? extends V> m) { |
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keyType = m.keyType; |
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keyUniverse = m.keyUniverse; |
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vals = m.vals.clone(); |
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size = m.size; |
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} |
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/** |
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* Creates an enum map initialized from the specified map. If the |
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* specified map is an <tt>EnumMap</tt> instance, this constructor behaves |
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* identically to {@link #EnumMap(EnumMap)}. Otherwise, the specified map |
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* must contain at least one mapping (in order to determine the new |
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* enum map's key type). |
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* |
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* @param m the map from which to initialize this enum map |
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* @throws IllegalArgumentException if <tt>m</tt> is not an |
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* <tt>EnumMap</tt> instance and contains no mappings |
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* @throws NullPointerException if <tt>m</tt> is null |
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*/ |
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public EnumMap(Map<K, ? extends V> m) { |
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if (m instanceof EnumMap) { |
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EnumMap<K, ? extends V> em = (EnumMap<K, ? extends V>) m; |
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keyType = em.keyType; |
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keyUniverse = em.keyUniverse; |
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vals = em.vals.clone(); |
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size = em.size; |
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} else { |
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if (m.isEmpty()) |
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throw new IllegalArgumentException("Specified map is empty"); |
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keyType = m.keySet().iterator().next().getDeclaringClass(); |
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keyUniverse = getKeyUniverse(keyType); |
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vals = new Object[keyUniverse.length]; |
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putAll(m); |
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} |
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} |
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// Query Operations |
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/** |
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* Returns the number of key-value mappings in this map. |
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* |
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* @return the number of key-value mappings in this map |
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*/ |
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public int size() { |
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return size; |
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} |
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/** |
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* Returns <tt>true</tt> if this map maps one or more keys to the |
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* specified value. |
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* |
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* @param value the value whose presence in this map is to be tested |
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* @return <tt>true</tt> if this map maps one or more keys to this value |
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*/ |
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public boolean containsValue(Object value) { |
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value = maskNull(value); |
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for (Object val : vals) |
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if (value.equals(val)) |
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return true; |
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return false; |
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} |
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/** |
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* Returns <tt>true</tt> if this map contains a mapping for the specified |
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* key. |
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* |
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* @param key the key whose presence in this map is to be tested |
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* @return <tt>true</tt> if this map contains a mapping for the specified |
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* key |
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*/ |
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public boolean containsKey(Object key) { |
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return isValidKey(key) && vals[((Enum)key).ordinal()] != null; |
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} |
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private boolean containsMapping(Object key, Object value) { |
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return isValidKey(key) && |
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maskNull(value).equals(vals[((Enum)key).ordinal()]); |
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} |
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/** |
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* Returns the value to which the specified key is mapped, |
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* or {@code null} if this map contains no mapping for the key. |
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* |
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* <p>More formally, if this map contains a mapping from a key |
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* {@code k} to a value {@code v} such that {@code (key == k)}, |
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* then this method returns {@code v}; otherwise it returns |
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* {@code null}. (There can be at most one such mapping.) |
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* |
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* <p>A return value of {@code null} does not <i>necessarily</i> |
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* indicate that the map contains no mapping for the key; it's also |
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* possible that the map explicitly maps the key to {@code null}. |
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* The {@link #containsKey containsKey} operation may be used to |
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* distinguish these two cases. |
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*/ |
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public V get(Object key) { |
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return (isValidKey(key) ? |
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unmaskNull(vals[((Enum)key).ordinal()]) : null); |
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} |
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// Modification Operations |
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/** |
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* Associates the specified value with the specified key in this map. |
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* If the map previously contained a mapping for this key, the old |
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* value is replaced. |
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* |
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* @param key the key with which the specified value is to be associated |
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* @param value the value to be associated with the specified key |
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* |
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* @return the previous value associated with specified key, or |
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* <tt>null</tt> if there was no mapping for key. (A <tt>null</tt> |
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* return can also indicate that the map previously associated |
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* <tt>null</tt> with the specified key.) |
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* @throws NullPointerException if the specified key is null |
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*/ |
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public V put(K key, V value) { |
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typeCheck(key); |
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int index = key.ordinal(); |
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Object oldValue = vals[index]; |
262 |
vals[index] = maskNull(value); |
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if (oldValue == null) |
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size++; |
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return unmaskNull(oldValue); |
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} |
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||
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/** |
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* Removes the mapping for this key from this map if present. |
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* |
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* @param key the key whose mapping is to be removed from the map |
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* @return the previous value associated with specified key, or |
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* <tt>null</tt> if there was no entry for key. (A <tt>null</tt> |
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* return can also indicate that the map previously associated |
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* <tt>null</tt> with the specified key.) |
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*/ |
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public V remove(Object key) { |
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if (!isValidKey(key)) |
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return null; |
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int index = ((Enum)key).ordinal(); |
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Object oldValue = vals[index]; |
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vals[index] = null; |
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if (oldValue != null) |
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size--; |
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return unmaskNull(oldValue); |
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} |
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private boolean removeMapping(Object key, Object value) { |
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if (!isValidKey(key)) |
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return false; |
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int index = ((Enum)key).ordinal(); |
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if (maskNull(value).equals(vals[index])) { |
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vals[index] = null; |
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size--; |
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return true; |
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} |
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return false; |
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} |
|
299 |
||
300 |
/** |
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301 |
* Returns true if key is of the proper type to be a key in this |
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* enum map. |
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*/ |
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304 |
private boolean isValidKey(Object key) { |
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if (key == null) |
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return false; |
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307 |
||
308 |
// Cheaper than instanceof Enum followed by getDeclaringClass |
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Class keyClass = key.getClass(); |
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310 |
return keyClass == keyType || keyClass.getSuperclass() == keyType; |
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311 |
} |
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312 |
||
313 |
// Bulk Operations |
|
314 |
||
315 |
/** |
|
316 |
* Copies all of the mappings from the specified map to this map. |
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317 |
* These mappings will replace any mappings that this map had for |
|
318 |
* any of the keys currently in the specified map. |
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319 |
* |
|
320 |
* @param m the mappings to be stored in this map |
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321 |
* @throws NullPointerException the specified map is null, or if |
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322 |
* one or more keys in the specified map are null |
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323 |
*/ |
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324 |
public void putAll(Map<? extends K, ? extends V> m) { |
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325 |
if (m instanceof EnumMap) { |
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326 |
EnumMap<? extends K, ? extends V> em = |
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327 |
(EnumMap<? extends K, ? extends V>)m; |
|
328 |
if (em.keyType != keyType) { |
|
329 |
if (em.isEmpty()) |
|
330 |
return; |
|
331 |
throw new ClassCastException(em.keyType + " != " + keyType); |
|
332 |
} |
|
333 |
||
334 |
for (int i = 0; i < keyUniverse.length; i++) { |
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335 |
Object emValue = em.vals[i]; |
|
336 |
if (emValue != null) { |
|
337 |
if (vals[i] == null) |
|
338 |
size++; |
|
339 |
vals[i] = emValue; |
|
340 |
} |
|
341 |
} |
|
342 |
} else { |
|
343 |
super.putAll(m); |
|
344 |
} |
|
345 |
} |
|
346 |
||
347 |
/** |
|
348 |
* Removes all mappings from this map. |
|
349 |
*/ |
|
350 |
public void clear() { |
|
351 |
Arrays.fill(vals, null); |
|
352 |
size = 0; |
|
353 |
} |
|
354 |
||
355 |
// Views |
|
356 |
||
357 |
/** |
|
358 |
* This field is initialized to contain an instance of the entry set |
|
359 |
* view the first time this view is requested. The view is stateless, |
|
360 |
* so there's no reason to create more than one. |
|
361 |
*/ |
|
362 |
private transient Set<Map.Entry<K,V>> entrySet = null; |
|
363 |
||
364 |
/** |
|
365 |
* Returns a {@link Set} view of the keys contained in this map. |
|
366 |
* The returned set obeys the general contract outlined in |
|
367 |
* {@link Map#keySet()}. The set's iterator will return the keys |
|
368 |
* in their natural order (the order in which the enum constants |
|
369 |
* are declared). |
|
370 |
* |
|
371 |
* @return a set view of the keys contained in this enum map |
|
372 |
*/ |
|
373 |
public Set<K> keySet() { |
|
374 |
Set<K> ks = keySet; |
|
375 |
if (ks != null) |
|
376 |
return ks; |
|
377 |
else |
|
378 |
return keySet = new KeySet(); |
|
379 |
} |
|
380 |
||
381 |
private class KeySet extends AbstractSet<K> { |
|
382 |
public Iterator<K> iterator() { |
|
383 |
return new KeyIterator(); |
|
384 |
} |
|
385 |
public int size() { |
|
386 |
return size; |
|
387 |
} |
|
388 |
public boolean contains(Object o) { |
|
389 |
return containsKey(o); |
|
390 |
} |
|
391 |
public boolean remove(Object o) { |
|
392 |
int oldSize = size; |
|
393 |
EnumMap.this.remove(o); |
|
394 |
return size != oldSize; |
|
395 |
} |
|
396 |
public void clear() { |
|
397 |
EnumMap.this.clear(); |
|
398 |
} |
|
399 |
} |
|
400 |
||
401 |
/** |
|
402 |
* Returns a {@link Collection} view of the values contained in this map. |
|
403 |
* The returned collection obeys the general contract outlined in |
|
404 |
* {@link Map#values()}. The collection's iterator will return the |
|
405 |
* values in the order their corresponding keys appear in map, |
|
406 |
* which is their natural order (the order in which the enum constants |
|
407 |
* are declared). |
|
408 |
* |
|
409 |
* @return a collection view of the values contained in this map |
|
410 |
*/ |
|
411 |
public Collection<V> values() { |
|
412 |
Collection<V> vs = values; |
|
413 |
if (vs != null) |
|
414 |
return vs; |
|
415 |
else |
|
416 |
return values = new Values(); |
|
417 |
} |
|
418 |
||
419 |
private class Values extends AbstractCollection<V> { |
|
420 |
public Iterator<V> iterator() { |
|
421 |
return new ValueIterator(); |
|
422 |
} |
|
423 |
public int size() { |
|
424 |
return size; |
|
425 |
} |
|
426 |
public boolean contains(Object o) { |
|
427 |
return containsValue(o); |
|
428 |
} |
|
429 |
public boolean remove(Object o) { |
|
430 |
o = maskNull(o); |
|
431 |
||
432 |
for (int i = 0; i < vals.length; i++) { |
|
433 |
if (o.equals(vals[i])) { |
|
434 |
vals[i] = null; |
|
435 |
size--; |
|
436 |
return true; |
|
437 |
} |
|
438 |
} |
|
439 |
return false; |
|
440 |
} |
|
441 |
public void clear() { |
|
442 |
EnumMap.this.clear(); |
|
443 |
} |
|
444 |
} |
|
445 |
||
446 |
/** |
|
447 |
* Returns a {@link Set} view of the mappings contained in this map. |
|
448 |
* The returned set obeys the general contract outlined in |
|
449 |
* {@link Map#keySet()}. The set's iterator will return the |
|
450 |
* mappings in the order their keys appear in map, which is their |
|
451 |
* natural order (the order in which the enum constants are declared). |
|
452 |
* |
|
453 |
* @return a set view of the mappings contained in this enum map |
|
454 |
*/ |
|
455 |
public Set<Map.Entry<K,V>> entrySet() { |
|
456 |
Set<Map.Entry<K,V>> es = entrySet; |
|
457 |
if (es != null) |
|
458 |
return es; |
|
459 |
else |
|
460 |
return entrySet = new EntrySet(); |
|
461 |
} |
|
462 |
||
463 |
private class EntrySet extends AbstractSet<Map.Entry<K,V>> { |
|
464 |
public Iterator<Map.Entry<K,V>> iterator() { |
|
465 |
return new EntryIterator(); |
|
466 |
} |
|
467 |
public boolean contains(Object o) { |
|
468 |
if (!(o instanceof Map.Entry)) |
|
469 |
return false; |
|
470 |
Map.Entry entry = (Map.Entry)o; |
|
471 |
return containsMapping(entry.getKey(), entry.getValue()); |
|
472 |
} |
|
473 |
public boolean remove(Object o) { |
|
474 |
if (!(o instanceof Map.Entry)) |
|
475 |
return false; |
|
476 |
Map.Entry entry = (Map.Entry)o; |
|
477 |
return removeMapping(entry.getKey(), entry.getValue()); |
|
478 |
} |
|
479 |
public int size() { |
|
480 |
return size; |
|
481 |
} |
|
482 |
public void clear() { |
|
483 |
EnumMap.this.clear(); |
|
484 |
} |
|
485 |
public Object[] toArray() { |
|
486 |
return fillEntryArray(new Object[size]); |
|
487 |
} |
|
488 |
@SuppressWarnings("unchecked") |
|
489 |
public <T> T[] toArray(T[] a) { |
|
490 |
int size = size(); |
|
491 |
if (a.length < size) |
|
492 |
a = (T[])java.lang.reflect.Array |
|
493 |
.newInstance(a.getClass().getComponentType(), size); |
|
494 |
if (a.length > size) |
|
495 |
a[size] = null; |
|
496 |
return (T[]) fillEntryArray(a); |
|
497 |
} |
|
498 |
private Object[] fillEntryArray(Object[] a) { |
|
499 |
int j = 0; |
|
500 |
for (int i = 0; i < vals.length; i++) |
|
501 |
if (vals[i] != null) |
|
7803
56bc97d69d93
6880112: Project Coin: Port JDK core library code to use diamond operator
smarks
parents:
5506
diff
changeset
|
502 |
a[j++] = new AbstractMap.SimpleEntry<>( |
2 | 503 |
keyUniverse[i], unmaskNull(vals[i])); |
504 |
return a; |
|
505 |
} |
|
506 |
} |
|
507 |
||
508 |
private abstract class EnumMapIterator<T> implements Iterator<T> { |
|
509 |
// Lower bound on index of next element to return |
|
510 |
int index = 0; |
|
511 |
||
512 |
// Index of last returned element, or -1 if none |
|
513 |
int lastReturnedIndex = -1; |
|
514 |
||
515 |
public boolean hasNext() { |
|
516 |
while (index < vals.length && vals[index] == null) |
|
517 |
index++; |
|
518 |
return index != vals.length; |
|
519 |
} |
|
520 |
||
521 |
public void remove() { |
|
522 |
checkLastReturnedIndex(); |
|
523 |
||
524 |
if (vals[lastReturnedIndex] != null) { |
|
525 |
vals[lastReturnedIndex] = null; |
|
526 |
size--; |
|
527 |
} |
|
528 |
lastReturnedIndex = -1; |
|
529 |
} |
|
530 |
||
531 |
private void checkLastReturnedIndex() { |
|
532 |
if (lastReturnedIndex < 0) |
|
533 |
throw new IllegalStateException(); |
|
534 |
} |
|
535 |
} |
|
536 |
||
537 |
private class KeyIterator extends EnumMapIterator<K> { |
|
538 |
public K next() { |
|
539 |
if (!hasNext()) |
|
540 |
throw new NoSuchElementException(); |
|
541 |
lastReturnedIndex = index++; |
|
542 |
return keyUniverse[lastReturnedIndex]; |
|
543 |
} |
|
544 |
} |
|
545 |
||
546 |
private class ValueIterator extends EnumMapIterator<V> { |
|
547 |
public V next() { |
|
548 |
if (!hasNext()) |
|
549 |
throw new NoSuchElementException(); |
|
550 |
lastReturnedIndex = index++; |
|
551 |
return unmaskNull(vals[lastReturnedIndex]); |
|
552 |
} |
|
553 |
} |
|
554 |
||
555 |
/** |
|
556 |
* Since we don't use Entry objects, we use the Iterator itself as entry. |
|
557 |
*/ |
|
558 |
private class EntryIterator extends EnumMapIterator<Map.Entry<K,V>> |
|
559 |
implements Map.Entry<K,V> |
|
560 |
{ |
|
561 |
public Map.Entry<K,V> next() { |
|
562 |
if (!hasNext()) |
|
563 |
throw new NoSuchElementException(); |
|
564 |
lastReturnedIndex = index++; |
|
565 |
return this; |
|
566 |
} |
|
567 |
||
568 |
public K getKey() { |
|
569 |
checkLastReturnedIndexForEntryUse(); |
|
570 |
return keyUniverse[lastReturnedIndex]; |
|
571 |
} |
|
572 |
||
573 |
public V getValue() { |
|
574 |
checkLastReturnedIndexForEntryUse(); |
|
575 |
return unmaskNull(vals[lastReturnedIndex]); |
|
576 |
} |
|
577 |
||
578 |
public V setValue(V value) { |
|
579 |
checkLastReturnedIndexForEntryUse(); |
|
580 |
V oldValue = unmaskNull(vals[lastReturnedIndex]); |
|
581 |
vals[lastReturnedIndex] = maskNull(value); |
|
582 |
return oldValue; |
|
583 |
} |
|
584 |
||
585 |
public boolean equals(Object o) { |
|
586 |
if (lastReturnedIndex < 0) |
|
587 |
return o == this; |
|
588 |
||
589 |
if (!(o instanceof Map.Entry)) |
|
590 |
return false; |
|
591 |
Map.Entry e = (Map.Entry)o; |
|
592 |
V ourValue = unmaskNull(vals[lastReturnedIndex]); |
|
593 |
Object hisValue = e.getValue(); |
|
594 |
return e.getKey() == keyUniverse[lastReturnedIndex] && |
|
595 |
(ourValue == hisValue || |
|
596 |
(ourValue != null && ourValue.equals(hisValue))); |
|
597 |
} |
|
598 |
||
599 |
public int hashCode() { |
|
600 |
if (lastReturnedIndex < 0) |
|
601 |
return super.hashCode(); |
|
602 |
||
603 |
Object value = vals[lastReturnedIndex]; |
|
604 |
return keyUniverse[lastReturnedIndex].hashCode() |
|
605 |
^ (value == NULL ? 0 : value.hashCode()); |
|
606 |
} |
|
607 |
||
608 |
public String toString() { |
|
609 |
if (lastReturnedIndex < 0) |
|
610 |
return super.toString(); |
|
611 |
||
612 |
return keyUniverse[lastReturnedIndex] + "=" |
|
613 |
+ unmaskNull(vals[lastReturnedIndex]); |
|
614 |
} |
|
615 |
||
616 |
private void checkLastReturnedIndexForEntryUse() { |
|
617 |
if (lastReturnedIndex < 0) |
|
618 |
throw new IllegalStateException("Entry was removed"); |
|
619 |
} |
|
620 |
} |
|
621 |
||
622 |
// Comparison and hashing |
|
623 |
||
624 |
/** |
|
625 |
* Compares the specified object with this map for equality. Returns |
|
626 |
* <tt>true</tt> if the given object is also a map and the two maps |
|
627 |
* represent the same mappings, as specified in the {@link |
|
628 |
* Map#equals(Object)} contract. |
|
629 |
* |
|
630 |
* @param o the object to be compared for equality with this map |
|
631 |
* @return <tt>true</tt> if the specified object is equal to this map |
|
632 |
*/ |
|
633 |
public boolean equals(Object o) { |
|
634 |
if (!(o instanceof EnumMap)) |
|
635 |
return super.equals(o); |
|
636 |
||
637 |
EnumMap em = (EnumMap)o; |
|
638 |
if (em.keyType != keyType) |
|
639 |
return size == 0 && em.size == 0; |
|
640 |
||
641 |
// Key types match, compare each value |
|
642 |
for (int i = 0; i < keyUniverse.length; i++) { |
|
643 |
Object ourValue = vals[i]; |
|
644 |
Object hisValue = em.vals[i]; |
|
645 |
if (hisValue != ourValue && |
|
646 |
(hisValue == null || !hisValue.equals(ourValue))) |
|
647 |
return false; |
|
648 |
} |
|
649 |
return true; |
|
650 |
} |
|
651 |
||
652 |
/** |
|
653 |
* Returns a shallow copy of this enum map. (The values themselves |
|
654 |
* are not cloned. |
|
655 |
* |
|
656 |
* @return a shallow copy of this enum map |
|
657 |
*/ |
|
658 |
public EnumMap<K, V> clone() { |
|
659 |
EnumMap<K, V> result = null; |
|
660 |
try { |
|
661 |
result = (EnumMap<K, V>) super.clone(); |
|
662 |
} catch(CloneNotSupportedException e) { |
|
663 |
throw new AssertionError(); |
|
664 |
} |
|
51 | 665 |
result.vals = result.vals.clone(); |
2 | 666 |
return result; |
667 |
} |
|
668 |
||
669 |
/** |
|
670 |
* Throws an exception if e is not of the correct type for this enum set. |
|
671 |
*/ |
|
672 |
private void typeCheck(K key) { |
|
673 |
Class keyClass = key.getClass(); |
|
674 |
if (keyClass != keyType && keyClass.getSuperclass() != keyType) |
|
675 |
throw new ClassCastException(keyClass + " != " + keyType); |
|
676 |
} |
|
677 |
||
678 |
/** |
|
679 |
* Returns all of the values comprising K. |
|
680 |
* The result is uncloned, cached, and shared by all callers. |
|
681 |
*/ |
|
682 |
private static <K extends Enum<K>> K[] getKeyUniverse(Class<K> keyType) { |
|
683 |
return SharedSecrets.getJavaLangAccess() |
|
684 |
.getEnumConstantsShared(keyType); |
|
685 |
} |
|
686 |
||
687 |
private static final long serialVersionUID = 458661240069192865L; |
|
688 |
||
689 |
/** |
|
690 |
* Save the state of the <tt>EnumMap</tt> instance to a stream (i.e., |
|
691 |
* serialize it). |
|
692 |
* |
|
693 |
* @serialData The <i>size</i> of the enum map (the number of key-value |
|
694 |
* mappings) is emitted (int), followed by the key (Object) |
|
695 |
* and value (Object) for each key-value mapping represented |
|
696 |
* by the enum map. |
|
697 |
*/ |
|
698 |
private void writeObject(java.io.ObjectOutputStream s) |
|
699 |
throws java.io.IOException |
|
700 |
{ |
|
701 |
// Write out the key type and any hidden stuff |
|
702 |
s.defaultWriteObject(); |
|
703 |
||
704 |
// Write out size (number of Mappings) |
|
705 |
s.writeInt(size); |
|
706 |
||
707 |
// Write out keys and values (alternating) |
|
708 |
for (Map.Entry<K,V> e : entrySet()) { |
|
709 |
s.writeObject(e.getKey()); |
|
710 |
s.writeObject(e.getValue()); |
|
711 |
} |
|
712 |
} |
|
713 |
||
714 |
/** |
|
715 |
* Reconstitute the <tt>EnumMap</tt> instance from a stream (i.e., |
|
716 |
* deserialize it). |
|
717 |
*/ |
|
718 |
private void readObject(java.io.ObjectInputStream s) |
|
719 |
throws java.io.IOException, ClassNotFoundException |
|
720 |
{ |
|
721 |
// Read in the key type and any hidden stuff |
|
722 |
s.defaultReadObject(); |
|
723 |
||
724 |
keyUniverse = getKeyUniverse(keyType); |
|
725 |
vals = new Object[keyUniverse.length]; |
|
726 |
||
727 |
// Read in size (number of Mappings) |
|
728 |
int size = s.readInt(); |
|
729 |
||
730 |
// Read the keys and values, and put the mappings in the HashMap |
|
731 |
for (int i = 0; i < size; i++) { |
|
732 |
K key = (K) s.readObject(); |
|
733 |
V value = (V) s.readObject(); |
|
734 |
put(key, value); |
|
735 |
} |
|
736 |
} |
|
737 |
} |