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 */
017package org.apache.camel.spi;
018
019/**
020 * A pluggable strategy for creating and possibly dependency injecting objects
021 * which could be implemented using straight forward reflection or using Spring
022 * or CDI to perform dependency injection.
023 */
024public interface Injector {
025
026    /**
027     * Instantiates a new instance of the given type; possibly injecting values
028     * into the object in the process (bean post processing)
029     * 
030     * @param type the type of object to create
031     * @return a newly created instance
032     */
033    <T> T newInstance(Class<T> type);
034
035    /**
036     * Instantiates a new instance of the given type by using the factory method
037     * (this will not perform bean post processing)
038     *
039     * @param type the type of object to create
040     * @param factoryMethod to create the new instance via factory method which must be public static and return the type
041     * @return a newly created instance
042     */
043    <T> T newInstance(Class<T> type, String factoryMethod);
044
045    /**
046     * Instantiates a new instance of the given type; possibly injecting values
047     * into the object in the process (bean post processing if enabled)
048     *
049     * @param type the type of object to create
050     * @param postProcessBean whether to post process the bean
051     * @return a newly created instance
052     */
053    <T> T newInstance(Class<T> type, boolean postProcessBean);
054
055    /**
056     * Whether the injector supports creating new instances using auto-wiring.
057     * If this is possible then bean instances is attempt first to be created this way
058     * and if not, then the bean can only be created if there is a public no-arg constructor.
059     */
060    boolean supportsAutoWiring();
061
062}