tapestry/tapestry-framework/src/java/org/apache/tapestry/services/impl/DeferredObject.java

// Copyright 2005 The Apache Software Foundation
//
// 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.apache.tapestry.services.impl;

import org.apache.hivemind.Locatable;

/**
 * Interface for an object that can provide a second, target object. This encapsulates the process
 * of obtaining the target object (which is presumably expensive) so that the operation can be
 * deferred or even avoided.
 * 
 * @author Howard M. Lewis Ship
 * @since 4.0
 * @see org.apache.tapestry.services.impl.DeferredObjectTranslator
 */
public interface DeferredObject extends Locatable
{
    /**
     * Returns the target object. The caller is expected to cache the result, if appropriate.
     */
    Object getObject();

}