001/*
002 * Copyright 2002-2017 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 *      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.core;
018
019import org.springframework.lang.Nullable;
020
021/**
022 * Any object can implement this interface to provide its actual {@link ResolvableType}.
023 *
024 * <p>Such information is very useful when figuring out if the instance matches a generic
025 * signature as Java does not convey the signature at runtime.
026 *
027 * <p>Users of this interface should be careful in complex hierarchy scenarios, especially
028 * when the generic type signature of the class changes in sub-classes. It is always
029 * possible to return {@code null} to fallback on a default behavior.
030 *
031 * @author Stephane Nicoll
032 * @since 4.2
033 */
034public interface ResolvableTypeProvider {
035
036        /**
037         * Return the {@link ResolvableType} describing this instance
038         * (or {@code null} if some sort of default should be applied instead).
039         */
040        @Nullable
041        ResolvableType getResolvableType();
042
043}