001    /**
002     *
003     * Licensed to the Apache Software Foundation (ASF) under one or more
004     * contributor license agreements.  See the NOTICE file distributed with
005     * this work for additional information regarding copyright ownership.
006     * The ASF licenses this file to You under the Apache License, Version 2.0
007     * (the "License"); you may not use this file except in compliance with
008     * the License.  You may obtain a copy of the License at
009     *
010     * http://www.apache.org/licenses/LICENSE-2.0
011     *
012     * Unless required by applicable law or agreed to in writing, software
013     * distributed under the License is distributed on an "AS IS" BASIS,
014     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015     * See the License for the specific language governing permissions and
016     * limitations under the License.
017     */
018    package org.apache.camel.impl;
019    
020    import org.apache.camel.impl.converter.TypeConverterRegistry;
021    
022    /**
023     * A caching proxy so that a single 
024     * @version $Revision: 525537 $
025     */
026    public class CachingInjector<T> {
027        private final TypeConverterRegistry repository;
028        private final Class<T> type;
029        private T instance;
030    
031        public CachingInjector(TypeConverterRegistry repository, Class<T> type) {
032            this.repository = repository;
033            this.type = type;
034        }
035    
036        public synchronized T newInstance() {
037            if (instance == null) {
038                instance = createInstance(type);
039            }
040            return instance;
041        }
042    
043        protected T createInstance(Class<T> type) {
044            return (T) repository.getInjector().newInstance(type);
045        }
046    }