https://github.com/spring-projects/spring-framework: Spring Core (Spring IO)
  • Juergen Hoeller 
/*
 * Copyright 2002-2017 the original author or authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.springframework.core;

import org.springframework.lang.Nullable;


Any object can implement this interface to provide its actual ResolvableType. 
Such information is very useful when figuring out if the instance matches a generic
signature as Java does not convey the signature at runtime.

Users of this interface should be careful in complex hierarchy scenarios, especially when the generic type signature of the class changes in sub-classes. It is always possible to return null to fallback on a default behavior. 
Author:Stephane Nicoll
Since:4.2
/**
 * Any object can implement this interface to provide its actual {@link ResolvableType}.
 *
 * <p>Such information is very useful when figuring out if the instance matches a generic
 * signature as Java does not convey the signature at runtime.
 *
 * <p>Users of this interface should be careful in complex hierarchy scenarios, especially
 * when the generic type signature of the class changes in sub-classes. It is always
 * possible to return {@code null} to fallback on a default behavior.
 *
 * @author Stephane Nicoll
 * @since 4.2
 */
public interface ResolvableTypeProvider {

	
Return the ResolvableType describing this instance (or null if some sort of default should be applied instead). 
/**
	 * Return the {@link ResolvableType} describing this instance
	 * (or {@code null} if some sort of default should be applied instead).
	 */
	@Nullable
	ResolvableType getResolvableType();

}