001// Copyright 2011 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.tapestry5.ioc.internal.services;
016
017import org.apache.tapestry5.commons.AnnotationProvider;
018import org.apache.tapestry5.commons.ObjectLocator;
019import org.apache.tapestry5.commons.ObjectProvider;
020
021/**
022 * Provides a single object of a given type.
023 *
024 * @since 5.3
025 */
026public class StaticObjectProvider<S> implements ObjectProvider
027{
028    private final Class<S> valueType;
029
030    private final S value;
031
032    public StaticObjectProvider(Class<S> valueType, S value)
033    {
034        this.valueType = valueType;
035        this.value = value;
036
037        assert valueType != null;
038        assert value != null;
039    }
040
041
042    @Override
043    public <T> T provide(Class<T> objectType, AnnotationProvider annotationProvider, ObjectLocator locator)
044    {
045        if (objectType == valueType)
046        {
047            return objectType.cast(value);
048        }
049
050        return null;
051    }
052}