| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.bval.jsr.metadata; |
| |
| import java.util.EnumSet; |
| import java.util.Iterator; |
| import java.util.Objects; |
| import java.util.Set; |
| import java.util.function.Function; |
| import java.util.function.Predicate; |
| import java.util.stream.Collectors; |
| import java.util.stream.Stream; |
| |
| import org.apache.bval.util.Validate; |
| |
| @FunctionalInterface |
| public interface AnnotationBehaviorMergeStrategy |
| extends Function<Iterable<? extends HasAnnotationBehavior>, AnnotationBehavior> { |
| |
| public static AnnotationBehaviorMergeStrategy first() { |
| return coll -> { |
| final Iterator<? extends HasAnnotationBehavior> iterator = coll.iterator(); |
| return iterator.hasNext() ? iterator.next().getAnnotationBehavior() : AnnotationBehavior.ABSTAIN; |
| }; |
| } |
| |
| public static AnnotationBehaviorMergeStrategy consensus() { |
| return coll -> { |
| final Stream.Builder<HasAnnotationBehavior> b = Stream.builder(); |
| coll.forEach(b); |
| final Set<AnnotationBehavior> annotationBehaviors = |
| b.build().map(HasAnnotationBehavior::getAnnotationBehavior).filter(Objects::nonNull) |
| .filter(Predicate.isEqual(AnnotationBehavior.ABSTAIN).negate()) |
| .collect(Collectors.toCollection(() -> EnumSet.noneOf(AnnotationBehavior.class))); |
| Validate.validState(annotationBehaviors.size() <= 1, |
| "Conflicting annotation inclusion behaviors found among %s", coll); |
| return annotationBehaviors.isEmpty() ? AnnotationBehavior.ABSTAIN : annotationBehaviors.iterator().next(); |
| }; |
| } |
| } |