    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}