/*
* JBoss, Home of Professional Open Source
* Copyright 2014, Red Hat, Inc., and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* 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.jboss.weld.bean;
import java.lang.reflect.Method;
import java.lang.reflect.Type;
import java.util.ArrayList;
import java.util.List;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.jboss.weld.annotated.runtime.InvokableAnnotatedMethod;
import org.jboss.weld.manager.BeanManagerImpl;
import org.jboss.weld.resolution.CovariantTypes;
import org.jboss.weld.util.Decorators;
import org.jboss.weld.util.Types;
import org.jboss.weld.util.reflection.Reflections;
/**
* Resolves decorator method for a given business method.
*
* @author Jozef Hartinger
*
*/
class DecoratedMethods {
/*
* We use this marker because ConcurrentMap does not support null values but we want to keep track of
* methods for which there is no decorated method declared by the decorator.
*/
private static final Object NULL_MARKER = new Object();
private final Set<InvokableAnnotatedMethod<?>> decoratedTypeMethods;
private final ConcurrentMap<Method, Object> cache;
DecoratedMethods(BeanManagerImpl manager, WeldDecorator<?> decorator) {
this.decoratedTypeMethods = Decorators.getDecoratorMethods(manager, decorator);
this.cache = new ConcurrentHashMap<Method, Object>();
}
public InvokableAnnotatedMethod<?> getDecoratedMethod(Method method) {
if (!cache.containsKey(method)) {
// this is not atomic and we may end up doing method lookup more than once - which is fine
cache.putIfAbsent(method, findMatchingDecoratedMethod(method));
}
Object value = cache.get(method);
if (value == NULL_MARKER) {
return null;
} else {
return Reflections.cast(value);
}
}
private Object findMatchingDecoratedMethod(Method method) {
// First try to find the same method
for (InvokableAnnotatedMethod<?> decoratedMethod : decoratedTypeMethods) {
if (decoratedMethod.getJavaMember().equals(method)) {
return decoratedMethod;
}
}
// Then try to find all matching methods
List<InvokableAnnotatedMethod<?>> matching = new ArrayList<InvokableAnnotatedMethod<?>>();
for (InvokableAnnotatedMethod<?> decoratedMethod : decoratedTypeMethods) {
if (matches(decoratedMethod, method)) {
matching.add(decoratedMethod);
}
}
if (matching.isEmpty()) {
// No match
return NULL_MARKER;
} else if (matching.size() == 1) {
// If there is only one matching method no further action is needed
return matching.get(0);
}
// Choose the most specific method
// This does not meet all requirements of JLS but it should work in most cases
// See also JLS Java SE 8 Edition, 15.12.2.5 Choosing the Most Specific Method
InvokableAnnotatedMethod<?> mostSpecific = matching.get(0);
for (int i = 1; i < matching.size(); i++) {
InvokableAnnotatedMethod<?> candidate = matching.get(i);
if (isMoreSpecific(candidate, mostSpecific)) {
mostSpecific = candidate;
}
}
return mostSpecific;
}
private boolean matches(InvokableAnnotatedMethod<?> decoratedMethod, Method candidate) {
if (candidate.getParameterTypes().length != decoratedMethod.getParameters().size()) {
return false;
}
if (!candidate.getName().equals(decoratedMethod.getJavaMember().getName())) {
return false;
}
for (int i = 0; i < candidate.getParameterTypes().length; i++) {
Type decoratedMethodParamType = decoratedMethod.getJavaMember().getGenericParameterTypes()[i];
Type candidateParamType = candidate.getGenericParameterTypes()[i];
if (Types.containsTypeVariable(decoratedMethodParamType) || Types.containsTypeVariable(candidateParamType)) {
if (!decoratedMethod.getJavaMember().getParameterTypes()[i].isAssignableFrom(candidate.getParameterTypes()[i])) {
return false;
}
} else {
if (!CovariantTypes.isAssignableFrom(decoratedMethodParamType, candidateParamType)) {
return false;
}
}
}
return true;
}
private boolean isMoreSpecific(InvokableAnnotatedMethod<?> candidate, InvokableAnnotatedMethod<?> mostSpecific) {
for (int i = 0; i < candidate.getJavaMember().getGenericParameterTypes().length; i++) {
if (Types.isMoreSpecific(candidate.getJavaMember().getGenericParameterTypes()[i], mostSpecific.getJavaMember().getGenericParameterTypes()[i])) {
return true;
}
}
return false;
}
}