com.google.gwt.emul.java.util.AbstractMap Maven / Gradle / Ivy
/*
* Copyright 2007 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may not
* use this file except in compliance with the License. You may obtain a copy of
* the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations under
* the License.
*/
package java.util;
/**
* Skeletal implementation of the Map interface. [Sun
* docs]
*
* @param the key type.
* @param the value type.
*/
public abstract class AbstractMap implements Map {
protected AbstractMap() {
}
public void clear() {
entrySet().clear();
}
public boolean containsKey(Object key) {
return implFindEntry(key, false) != null;
}
public boolean containsValue(Object value) {
for (Iterator> iter = entrySet().iterator(); iter.hasNext();) {
Entry entry = iter.next();
V v = entry.getValue();
if (Objects.equals(value, v)) {
return true;
}
}
return false;
}
public abstract Set> entrySet();
@Override
public boolean equals(Object obj) {
if (obj == this) {
return true;
}
if (!(obj instanceof Map)) {
return false;
}
Map otherMap = (Map) obj;
if (size() != otherMap.size()) {
return false;
}
for (Entry entry : otherMap.entrySet()) {
Object otherKey = entry.getKey();
Object otherValue = entry.getValue();
if (!containsKey(otherKey)) {
return false;
}
if (!Objects.equals(otherValue, get(otherKey))) {
return false;
}
}
return true;
}
public V get(Object key) {
Map.Entry entry = implFindEntry(key, false);
return (entry == null ? null : entry.getValue());
}
@Override
public int hashCode() {
int hashCode = 0;
for (Entry entry : entrySet()) {
hashCode += entry.hashCode();
hashCode = ~~hashCode;
}
return hashCode;
}
public boolean isEmpty() {
return size() == 0;
}
public Set keySet() {
final Set> entrySet = entrySet();
return new AbstractSet() {
@Override
public boolean contains(Object key) {
return containsKey(key);
}
@Override
public Iterator iterator() {
final Iterator> outerIter = entrySet.iterator();
return new Iterator() {
public boolean hasNext() {
return outerIter.hasNext();
}
public K next() {
Map.Entry entry = outerIter.next();
return entry.getKey();
}
public void remove() {
outerIter.remove();
}
};
}
@Override
public int size() {
return entrySet.size();
}
};
}
public V put(K key, V value) {
throw new UnsupportedOperationException("Put not supported on this map");
}
public void putAll(Map t) {
for (Iterator> iter = t.entrySet().iterator();
iter.hasNext(); ) {
Entry e = iter.next();
put(e.getKey(), e.getValue());
}
}
public V remove(Object key) {
Map.Entry entry = implFindEntry(key, true);
return (entry == null ? null : entry.getValue());
}
public int size() {
return entrySet().size();
}
@Override
public String toString() {
String s = "{";
boolean comma = false;
for (Iterator> iter = entrySet().iterator(); iter.hasNext();) {
Entry entry = iter.next();
if (comma) {
s += ", ";
} else {
comma = true;
}
s += String.valueOf(entry.getKey());
s += "=";
s += String.valueOf(entry.getValue());
}
return s + "}";
}
public Collection values() {
final Set> entrySet = entrySet();
return new AbstractCollection() {
@Override
public boolean contains(Object value) {
return containsValue(value);
}
@Override
public Iterator iterator() {
final Iterator> outerIter = entrySet.iterator();
return new Iterator() {
public boolean hasNext() {
return outerIter.hasNext();
}
public V next() {
V value = outerIter.next().getValue();
return value;
}
public void remove() {
outerIter.remove();
}
};
}
@Override
public int size() {
return entrySet.size();
}
};
}
private Entry implFindEntry(Object key, boolean remove) {
for (Iterator> iter = entrySet().iterator(); iter.hasNext();) {
Entry entry = iter.next();
K k = entry.getKey();
if (Objects.equals(key, k)) {
if (remove) {
entry = new MapEntryImpl(entry.getKey(), entry.getValue());
iter.remove();
}
return entry;
}
}
return null;
}
}