/*
 * Copyright 2002-2018 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 java.lang.reflect.Constructor;
import java.lang.reflect.Method;

import org.springframework.lang.Nullable;

Interface to discover parameter names for methods and constructors.
Parameter name discovery is not always possible, but various strategies are
available to try, such as looking for debug information that may have been
emitted at compile time, and looking for argname annotation values optionally
accompanying AspectJ annotated methods.
Author:
Rod Johnson, Adrian Colyer
Since:
2.0/**
 * Interface to discover parameter names for methods and constructors.
 *
 * <p>Parameter name discovery is not always possible, but various strategies are
 * available to try, such as looking for debug information that may have been
 * emitted at compile time, and looking for argname annotation values optionally
 * accompanying AspectJ annotated methods.
 *
 * @author Rod Johnson
 * @author Adrian Colyer
 * @since 2.0
 */
public interface ParameterNameDiscoverer {

	
Return parameter names for a method, or null if they cannot be determined. 
Individual entries in the array may be null if parameter names are only available for some parameters of the given method but not for others. However, it is recommended to use stub parameter names instead wherever feasible. 
Params:
method – the method to find parameter names for
Returns:
an array of parameter names if the names can be resolved, or null if they cannot/**
	 * Return parameter names for a method, or {@code null} if they cannot be determined.
	 * <p>Individual entries in the array may be {@code null} if parameter names are only
	 * available for some parameters of the given method but not for others. However,
	 * it is recommended to use stub parameter names instead wherever feasible.
	 * @param method the method to find parameter names for
	 * @return an array of parameter names if the names can be resolved,
	 * or {@code null} if they cannot
	 */
	@Nullable
	String[] getParameterNames(Method method);

	
Return parameter names for a constructor, or null if they cannot be determined. 
Individual entries in the array may be null if parameter names are only available for some parameters of the given constructor but not for others. However, it is recommended to use stub parameter names instead wherever feasible. 
Params:
ctor – the constructor to find parameter names for
Returns:
an array of parameter names if the names can be resolved, or null if they cannot/**
	 * Return parameter names for a constructor, or {@code null} if they cannot be determined.
	 * <p>Individual entries in the array may be {@code null} if parameter names are only
	 * available for some parameters of the given constructor but not for others. However,
	 * it is recommended to use stub parameter names instead wherever feasible.
	 * @param ctor the constructor to find parameter names for
	 * @return an array of parameter names if the names can be resolved,
	 * or {@code null} if they cannot
	 */
	@Nullable
	String[] getParameterNames(Constructor<?> ctor);

}