org.springframework.webflow.AttributeCollection 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 org.springframework.binding.util.MapAdaptable;
/**
* An interface for objects that manage the storage of attribute values.
*
* @author Keith Donald
*/
public interface AttributeCollection extends MapAdaptable {
/**
* Returns the number of attributes in this collection.
* @return the number of attributes in this collection
*/
public int size();
/**
* Get an attribute value out of this collection, returning
* null if not found.
* @param attributeName the attribute name
* @return the attribute value
*/
public Object get(String attributeName);
/**
* Returns this collection as an {@link UnmodifiableAttributeMap}, which
* provides access to the attributes in this collection in an immutable,
* more strongly-typed manner.
* @return the attribute collection as an unmodifiable map.
*/
public UnmodifiableAttributeMap unmodifiable();
/**
* Merge the attributes in the provided collection this collection and
* return a copy containing the union.
* @param attributes the attributes to merge in; if null, this should be returned.
* @return a new attribute collection, the union of this collection and the one provided;
* or this, if a null attributes argument was provided.
*/
public AttributeCollection union(AttributeCollection attributes);
}