cn.taketoday.core.ParameterNameDiscoverer Maven / Gradle / Ivy
/*
* Original Author -> Harry Yang ([email protected]) https://taketoday.cn
* Copyright © TODAY & 2017 - 2021 All Rights Reserved.
*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see [http://www.gnu.org/licenses/]
*/
package cn.taketoday.core;
import java.lang.reflect.Executable;
import java.lang.reflect.Method;
import cn.taketoday.lang.Constant;
import cn.taketoday.lang.Nullable;
/**
* abstract class 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
* @author Adrian Colyer
* @author TODAY 2021/9/10 22:33
* @since 4.0
*/
public abstract class ParameterNameDiscoverer {
/**
* Return parameter names for an Executable(method or constructor), or {@code null}
* if they cannot be determined.
*
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 executable the Executable(method or constructor) to find parameter names for
* @return an array of parameter names if the names can be resolved,
* or {@code null} if they cannot
* @see Executable#getParameterCount()
*/
@Nullable
public String[] getParameterNames(@Nullable Executable executable) {
if (executable == null) {
return null;
}
if (executable.getParameterCount() == 0) {
return Constant.EMPTY_STRING_ARRAY;
}
if (executable instanceof Method) {
executable = BridgeMethodResolver.findBridgedMethod((Method) executable);
}
return doGet(executable);
}
@Nullable
protected String[] doGet(Executable executable) {
return null;
}
}