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 java.lang.reflect.Constructor; 020import java.lang.reflect.Method; 021import java.lang.reflect.Parameter; 022 023import org.springframework.lang.UsesJava8; 024 025/** 026 * {@link ParameterNameDiscoverer} implementation which uses JDK 8's reflection facilities 027 * for introspecting parameter names (based on the "-parameters" compiler flag). 028 * 029 * @author Juergen Hoeller 030 * @since 4.0 031 * @see java.lang.reflect.Method#getParameters() 032 * @see java.lang.reflect.Parameter#getName() 033 */ 034@UsesJava8 035public class StandardReflectionParameterNameDiscoverer implements ParameterNameDiscoverer { 036 037 @Override 038 public String[] getParameterNames(Method method) { 039 Parameter[] parameters = method.getParameters(); 040 String[] parameterNames = new String[parameters.length]; 041 for (int i = 0; i < parameters.length; i++) { 042 Parameter param = parameters[i]; 043 if (!param.isNamePresent()) { 044 return null; 045 } 046 parameterNames[i] = param.getName(); 047 } 048 return parameterNames; 049 } 050 051 @Override 052 public String[] getParameterNames(Constructor<?> ctor) { 053 Parameter[] parameters = ctor.getParameters(); 054 String[] parameterNames = new String[parameters.length]; 055 for (int i = 0; i < parameters.length; i++) { 056 Parameter param = parameters[i]; 057 if (!param.isNamePresent()) { 058 return null; 059 } 060 parameterNames[i] = param.getName(); 061 } 062 return parameterNames; 063 } 064 065}