org.springframework.core.annotation.MissingMergedAnnotation Maven / Gradle / Ivy

Show more of this group Show more artifacts with this name
Show all versions of spring-core Show documentation
Spring Core
There is a newer version: 6.1.6
/*
 * Copyright 2002-2019 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
 *
 *      https://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.springframework.core.annotation;

import java.lang.annotation.Annotation;
import java.util.Collections;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Optional;
import java.util.function.Function;
import java.util.function.Predicate;

import org.springframework.lang.Nullable;

/**
 * An {@link AbstractMergedAnnotation} used as the implementation of
 * {@link MergedAnnotation#missing()}.
 *
 * @author Phillip Webb
 * @author Juergen Hoeller
 * @since 5.2
 * @param  the annotation type
 */
final class MissingMergedAnnotation extends AbstractMergedAnnotation {

	private static final MissingMergedAnnotation INSTANCE = new MissingMergedAnnotation<>();


	private MissingMergedAnnotation() {
	}


	@Override
	public Class getType() {
		throw new NoSuchElementException("Unable to get type for missing annotation");
	}

	@Override
	public boolean isPresent() {
		return false;
	}

	@Override
	@Nullable
	public Object getSource() {
		return null;
	}

	@Override
	@Nullable
	public MergedAnnotation getMetaSource() {
		return null;
	}

	@Override
	public MergedAnnotation getRoot() {
		return this;
	}

	@Override
	public List> getMetaTypes() {
		return Collections.emptyList();
	}

	@Override
	public int getDistance() {
		return -1;
	}

	@Override
	public int getAggregateIndex() {
		return -1;
	}

	@Override
	public boolean hasNonDefaultValue(String attributeName) {
		throw new NoSuchElementException(
				"Unable to check non-default value for missing annotation");
	}

	@Override
	public boolean hasDefaultValue(String attributeName) {
		throw new NoSuchElementException(
				"Unable to check default value for missing annotation");
	}

	@Override
	public  Optional getValue(String attributeName, Class type) {
		return Optional.empty();
	}

	@Override
	public  Optional getDefaultValue(@Nullable String attributeName, Class type) {
		return Optional.empty();
	}

	@Override
	public MergedAnnotation filterAttributes(Predicate predicate) {
		return this;
	}

	@Override
	public MergedAnnotation withNonMergedAttributes() {
		return this;
	}

	@Override
	public AnnotationAttributes asAnnotationAttributes(Adapt... adaptations) {
		return new AnnotationAttributes();
	}

	@Override
	public Map asMap(Adapt... adaptations) {
		return Collections.emptyMap();
	}

	@Override
	public > T asMap(Function, T> factory, Adapt... adaptations) {
		return factory.apply(this);
	}

	@Override
	public String toString() {
		return "(missing)";
	}

	@Override
	public  MergedAnnotation getAnnotation(String attributeName,
			Class type) throws NoSuchElementException {

		throw new NoSuchElementException(
				"Unable to get attribute value for missing annotation");
	}

	@Override
	public  MergedAnnotation[] getAnnotationArray(
			String attributeName, Class type) throws NoSuchElementException {

		throw new NoSuchElementException(
				"Unable to get attribute value for missing annotation");
	}

	@Override
	protected  T getAttributeValue(String attributeName, Class type) {
		throw new NoSuchElementException(
				"Unable to get attribute value for missing annotation");
	}

	@Override
	protected A createSynthesized() {
		throw new NoSuchElementException("Unable to synthesize missing annotation");
	}


	@SuppressWarnings("unchecked")
	static  MergedAnnotation getInstance() {
		return (MergedAnnotation) INSTANCE;
	}

}