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Micro Distribution of the Payara Project
/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 2019 Payara Foundation and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* https://github.com/payara/Payara/blob/master/LICENSE.txt
* See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at glassfish/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* The Payara Foundation designates this particular file as subject to the "Classpath"
* exception as provided by the Payara Foundation in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
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package fish.payara.microprofile.faulttolerance.policy;
import java.lang.reflect.GenericArrayType;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.lang.reflect.TypeVariable;
import java.lang.reflect.WildcardType;
import org.eclipse.microprofile.faulttolerance.Fallback;
/**
* Utility class to find a {@link Method} of a certain name with the same argument types as a given sample method as
* required to lookup the {@link Fallback}'s fallback method.
*
* @author Jan Bernitt
*/
public final class MethodLookupUtils {
private MethodLookupUtils() {
// util
}
public static Method findMethodWithMatchingNameAndArguments(String name, Method sample) {
Class> currentType = sample.getDeclaringClass();
while (currentType != Object.class) {
try {
Method candidate = currentType.getDeclaredMethod(name, sample.getParameterTypes());
if (isMatchingParameterList(sample, candidate)) {
return candidate;
}
} catch (NoSuchMethodException | SecurityException e) {
// continue search
}
for (Method candidate : currentType.getDeclaredMethods()) {
if (name.equals(candidate.getName()) && isMatchingParameterList(sample, candidate)) {
return candidate;
}
}
for (Class> implemented : currentType.getInterfaces()) {
for (Method candidate : implemented.getDeclaredMethods()) {
if (name.equals(candidate.getName()) && isMatchingParameterList(sample, candidate)) {
return candidate;
}
}
}
currentType = currentType.getSuperclass();
}
return null;
}
private static boolean isMatchingParameterList(Method sample, Method candidate) {
return isMatchingParameterList(sample.getGenericParameterTypes(), candidate.getGenericParameterTypes());
}
private static boolean isMatchingParameterList(Type[] samples, Type[] candidates) {
if (samples.length != candidates.length) {
return false;
}
for (int i = 0; i < samples.length; i++) {
if (!isMatchingType(samples[i], candidates[i])) {
return false;
}
}
return true;
}
private static boolean isMatchingType(Type sample, Type candidate) {
return sample.equals(candidate)
|| (candidate instanceof TypeVariable)
|| (candidate instanceof GenericArrayType)
|| isMatchingGenericType(sample, candidate)
|| isMatchingWildcardType(sample, candidate);
}
private static boolean isMatchingWildcardType(Type sample, Type candidate) {
if (sample instanceof WildcardType && candidate instanceof WildcardType) {
WildcardType sampleType = (WildcardType) sample;
WildcardType candidateType = (WildcardType) candidate;
return isMatchingParameterList(sampleType.getLowerBounds(), candidateType.getLowerBounds())
&& isMatchingParameterList(sampleType.getUpperBounds(), candidateType.getUpperBounds());
}
return false;
}
private static boolean isMatchingGenericType(Type sample, Type candidate) {
if (sample instanceof ParameterizedType && candidate instanceof ParameterizedType) {
ParameterizedType sampleType = (ParameterizedType) sample;
ParameterizedType candidateType = (ParameterizedType) candidate;
if (sampleType.getRawType() != candidateType.getRawType()) {
return false;
}
return isMatchingParameterList(sampleType.getActualTypeArguments(),
candidateType.getActualTypeArguments());
}
return false;
}
}