001/*
002 * Copyright 2002-2016 the original author or authors.
003 *
004 * Licensed under the Apache License, Version 2.0 (the "License");
005 * you may not use this file except in compliance with the License.
006 * You may obtain a copy of the License at
007 *
008 *      https://www.apache.org/licenses/LICENSE-2.0
009 *
010 * Unless required by applicable law or agreed to in writing, software
011 * distributed under the License is distributed on an "AS IS" BASIS,
012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013 * See the License for the specific language governing permissions and
014 * limitations under the License.
015 */
016
017package org.springframework.context.annotation;
018
019/**
020 * A {@link Condition} that offers more fine-grained control when used with
021 * {@code @Configuration}. Allows certain {@link Condition}s to adapt when they match
022 * based on the configuration phase. For example, a condition that checks if a bean
023 * has already been registered might choose to only be evaluated during the
024 * {@link ConfigurationPhase#REGISTER_BEAN REGISTER_BEAN} {@link ConfigurationPhase}.
025 *
026 * @author Phillip Webb
027 * @since 4.0
028 * @see Configuration
029 */
030public interface ConfigurationCondition extends Condition {
031
032        /**
033         * Return the {@link ConfigurationPhase} in which the condition should be evaluated.
034         */
035        ConfigurationPhase getConfigurationPhase();
036
037
038        /**
039         * The various configuration phases where the condition could be evaluated.
040         */
041        enum ConfigurationPhase {
042
043                /**
044                 * The {@link Condition} should be evaluated as a {@code @Configuration}
045                 * class is being parsed.
046                 * <p>If the condition does not match at this point, the {@code @Configuration}
047                 * class will not be added.
048                 */
049                PARSE_CONFIGURATION,
050
051                /**
052                 * The {@link Condition} should be evaluated when adding a regular
053                 * (non {@code @Configuration}) bean. The condition will not prevent
054                 * {@code @Configuration} classes from being added.
055                 * <p>At the time that the condition is evaluated, all {@code @Configuration}s
056                 * will have been parsed.
057                 */
058                REGISTER_BEAN
059        }
060
061}