001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *      http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.camel.guice.impl;
018    
019    import org.apache.camel.IsSingleton;
020    import org.apache.camel.spi.Injector;
021    
022    /**
023     * An injector which uses Guice to perform the dependency injection of types
024     *
025     * @version $Revision: 2987 $
026     */
027    public class GuiceInjector implements Injector {
028        private final com.google.inject.Injector injector;
029    
030        public GuiceInjector(com.google.inject.Injector injector) {
031            this.injector = injector;
032        }
033    
034        public <T> T newInstance(Class<T> type) {
035            // TODO if not bound we could create an instance and inject it?
036            //injector.injectMembers(instance);
037            return injector.getInstance(type);
038        }
039    
040        public <T> T newInstance(Class<T> type, Object instance) {
041            if (instance instanceof IsSingleton) {
042                boolean singleton = ((IsSingleton) instance).isSingleton();
043                if (singleton) {
044                    return type.cast(instance);
045                }
046            }
047            return newInstance(type);
048        }
049    
050    }