001/*
002 * Copyright 2012-2017 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 *      http://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.boot.autoconfigure.condition;
018
019import java.lang.annotation.Documented;
020import java.lang.annotation.ElementType;
021import java.lang.annotation.Retention;
022import java.lang.annotation.RetentionPolicy;
023import java.lang.annotation.Target;
024
025import org.springframework.context.annotation.Conditional;
026
027/**
028 * {@link Conditional} that only matches when the specified classes are on the classpath.
029 *
030 * @author Phillip Webb
031 */
032@Target({ ElementType.TYPE, ElementType.METHOD })
033@Retention(RetentionPolicy.RUNTIME)
034@Documented
035@Conditional(OnClassCondition.class)
036public @interface ConditionalOnClass {
037
038        /**
039         * The classes that must be present. Since this annotation is parsed by loading class
040         * bytecode, it is safe to specify classes here that may ultimately not be on the
041         * classpath, only if this annotation is directly on the affected component and
042         * <b>not</b> if this annotation is used as a composed, meta-annotation. In order to
043         * use this annotation as a meta-annotation, only use the {@link #name} attribute.
044         * @return the classes that must be present
045         */
046        Class<?>[] value() default {};
047
048        /**
049         * The classes names that must be present.
050         * @return the class names that must be present.
051         */
052        String[] name() default {};
053
054}