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.Location; 018import org.apache.hivemind.internal.Module; 019import org.apache.hivemind.schema.Translator; 020 021/** 022 * An encapsulation of an invocation of 023 * {@link org.apache.hivemind.schema.Translator#translate(org.apache.hivemind.internal.Module, java.lang.Class, java.lang.String, org.apache.hivemind.Location)}, 024 * allowing the actual invocation (and all the object creation, etc., that entails) to be deferred, 025 * or even avoided all together. 026 * 027 * @author Howard M. Lewis Ship 028 * @since 4.0 029 */ 030public class DeferredObjectImpl implements DeferredObject 031{ 032 private final Module _module; 033 034 private final Translator _objectTranslator; 035 036 private final String _objectReference; 037 038 private final Location _location; 039 040 private Object _object; 041 042 public DeferredObjectImpl(final Translator objectTranslator, final Module module, 043 final String objectReference, final Location location) 044 { 045 _objectTranslator = objectTranslator; 046 _module = module; 047 _objectReference = objectReference; 048 _location = location; 049 } 050 051 public synchronized Object getObject() 052 { 053 if (_object == null) 054 _object = _objectTranslator.translate( 055 _module, 056 Object.class, 057 _objectReference, 058 _location); 059 060 return _object; 061 } 062 063 public Location getLocation() 064 { 065 return _location; 066 } 067}