gradle-master/subprojects/model-core/src/main/java/org/gradle/internal/reflect/annotations/TypeAnnotationMetadataStore.java
/*
 * Copyright 2019 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
 *
 *      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.gradle.internal.reflect.annotations;

import org.gradle.internal.reflect.validation.TypeValidationContext;

/**
 * A validating metadata store that handles annotations on types and their JavaBeans properties.
 *
 * <p>
 * The store considers property annotations to belong to {@linkplain AnnotationCategory categories}.
 * Each property can have at most one annotation per category.
 * Validation failures with a given type can be visited using {@link TypeAnnotationMetadata#visitValidationFailures(TypeValidationContext)}.
 * </p>
 *
 * <strong>Property annotation inheritance</strong>
 *
 * <p>
 * Property annotations are inherited from super-types on a per-category basis: subtypes can override each super-type annotation category separately.
 * If a subtype doesn't override a super-type defined category, the corresponding annotation in that category gets inherited.
 * Subtypes can mark methods to be ignored by using an ignore annotation.
 * Ignored methods don't inherit super-type annotations.
 * </p>
 *
 * <strong>Boolean properties</strong>
 *
 * <p>
 * In JavaBeans, {@code boolean} properties are allowed to be accessed both via {@code is}-getters and {@code get}-getters.
 * However, when both getter methods are present, Gradle needs to decide which method to use to access the property value. This can be solved
 * by explicitly ignoring one of the two getters using the ignore annotation.
 * </p>
 *
 * <p>
 * A special case of this is when both getters are generated by Groovy.
 * The store implementation can be supplied with a {@link java.util.function.Predicate} to identify generated getters.
 * If the {@code is}-getter is generated, and the {@code get}-getter is not ignored explicitly, then the generated
 * {@code is}-getter is automatically ignored in favor of the {@code get}-getter.
 * </p>
 */
public interface TypeAnnotationMetadataStore {
    TypeAnnotationMetadata getTypeAnnotationMetadata(Class<?> type);
}
