001// Copyright 2005 The Apache Software Foundation 002// 003// Licensed under the Apache License, Version 2.0 (the "License"); 004// you may not use this file except in compliance with the License. 005// You may obtain a copy of the License at 006// 007// http://www.apache.org/licenses/LICENSE-2.0 008// 009// Unless required by applicable law or agreed to in writing, software 010// distributed under the License is distributed on an "AS IS" BASIS, 011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 012// See the License for the specific language governing permissions and 013// limitations under the License. 014 015package org.apache.tapestry.services.impl; 016 017import org.apache.hivemind.Locatable; 018 019/** 020 * Interface for an object that can provide a second, target object. This encapsulates the process 021 * of obtaining the target object (which is presumably expensive) so that the operation can be 022 * deferred or even avoided. 023 * 024 * @author Howard M. Lewis Ship 025 * @since 4.0 026 * @see org.apache.tapestry.services.impl.DeferredObjectTranslator 027 */ 028public interface DeferredObject extends Locatable 029{ 030 /** 031 * Returns the target object. The caller is expected to cache the result, if appropriate. 032 */ 033 public Object getObject(); 034 035}