org.springframework.core.StandardReflectionParameterNameDiscoverer Maven / Gradle / Ivy
/*
* Copyright 2002-2022 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
*
* https://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 java.lang.reflect.Parameter;
import org.springframework.lang.Nullable;
/**
* {@link ParameterNameDiscoverer} implementation which uses JDK 8's reflection facilities
* for introspecting parameter names (based on the "-parameters" compiler flag).
*
* This is a key element of {@link DefaultParameterNameDiscoverer} where it is being
* combined with {@link KotlinReflectionParameterNameDiscoverer} if Kotlin is present.
*
* @author Juergen Hoeller
* @since 4.0
* @see java.lang.reflect.Method#getParameters()
* @see java.lang.reflect.Parameter#getName()
* @see KotlinReflectionParameterNameDiscoverer
* @see DefaultParameterNameDiscoverer
*/
public class StandardReflectionParameterNameDiscoverer implements ParameterNameDiscoverer {
@Override
@Nullable
public String[] getParameterNames(Method method) {
return getParameterNames(method.getParameters());
}
@Override
@Nullable
public String[] getParameterNames(Constructor ctor) {
return getParameterNames(ctor.getParameters());
}
@Nullable
private String[] getParameterNames(Parameter[] parameters) {
String[] parameterNames = new String[parameters.length];
for (int i = 0; i < parameters.length; i++) {
Parameter param = parameters[i];
if (!param.isNamePresent()) {
return null;
}
parameterNames[i] = param.getName();
}
return parameterNames;
}
}