juzu.impl.common.SimpleMap Maven / Gradle / Ivy
/*
* Copyright 2013 eXo Platform SAS
*
* 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 juzu.impl.common;
import java.util.AbstractMap;
import java.util.AbstractSet;
import java.util.Iterator;
import java.util.Set;
/**
* Make implementation of maps easier. Note that this map is not optimized for speed on all operations, the goal
* of this map is to make easy the implementation of maps.
*
* @author Julien Viet
*/
public abstract class SimpleMap extends AbstractMap {
protected abstract Iterator keys();
@Override
public abstract V get(Object key);
@Override
public final boolean containsKey(Object key) {
return get(key) != null;
}
@Override
public final Set> entrySet() {
return entries;
}
private AbstractSet> entries = new AbstractSet>() {
@Override
public Iterator> iterator() {
final Iterator names = keys();
return new Iterator>() {
public boolean hasNext() {
return names.hasNext();
}
public Entry next() {
final K name = names.next();
return new Entry() {
public K getKey() {
return name;
}
public V getValue() {
return get(name);
}
public V setValue(V value) {
throw new UnsupportedOperationException();
}
};
}
public void remove() {
throw new UnsupportedOperationException();
}
};
}
@Override
public int size() {
int size = 0;
for (Iterator names = keys();names.hasNext();) {
size++;
}
return size;
}
};
}