org.springframework.webflow.UnmodifiableAttributeMap Maven / Gradle / Ivy
/*
* Copyright 2002-2006 the original author or authors.
*
* 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 org.springframework.webflow;
import java.util.Collections;
import java.util.HashMap;
import java.util.Map;
/**
* An attribute map that encapsulates mutable {@link Map} operations. Useful for
* passing around when modification of the target map should be always
* disallowed.
*
* @author Keith Donald
*/
public class UnmodifiableAttributeMap extends AbstractAttributeMap {
/**
* Creates a new attribute map, initially empty.
*/
public UnmodifiableAttributeMap(Map attributes) {
if (attributes == null) {
attributes = Collections.EMPTY_MAP;
}
initAttributes(attributes);
}
public boolean equals(Object o) {
if (!(o instanceof UnmodifiableAttributeMap)) {
return false;
}
UnmodifiableAttributeMap other = (UnmodifiableAttributeMap)o;
return getMapInternal().equals(other.getMapInternal());
}
public int hashCode() {
return getMapInternal().hashCode();
}
public UnmodifiableAttributeMap unmodifiable() {
return this;
}
public AttributeCollection union(AttributeCollection attributes) {
if (attributes == null) {
return this;
} else {
Map map = new HashMap();
map.putAll(getMapInternal());
map.putAll(attributes.getMap());
return new UnmodifiableAttributeMap(map);
}
}
}