/*
* Copyright 2002-2017 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.springframework.context.index;
import java.util.HashSet;
import java.util.LinkedHashSet;
import java.util.Set;
import javax.lang.model.element.AnnotationMirror;
import javax.lang.model.element.Element;
import javax.lang.model.element.ElementKind;
/**
* A {@link StereotypesProvider} implementation that extracts the stereotypes
* flagged by the {@value INDEXED_ANNOTATION} annotation. This implementation
* honors stereotypes defined this way on meta-annotations.
*
* @author Stephane Nicoll
* @since 5.0
*/
class IndexedStereotypesProvider implements StereotypesProvider {
private static final String INDEXED_ANNOTATION = "org.springframework.stereotype.Indexed";
private final TypeHelper typeHelper;
public IndexedStereotypesProvider(TypeHelper typeHelper) {
this.typeHelper = typeHelper;
}
@Override
public Set<String> getStereotypes(Element element) {
Set<String> stereotypes = new LinkedHashSet<>();
ElementKind kind = element.getKind();
if (kind != ElementKind.CLASS && kind != ElementKind.INTERFACE) {
return stereotypes;
}
Set<Element> seen = new HashSet<>();
collectStereotypesOnAnnotations(seen, stereotypes, element);
seen = new HashSet<>();
collectStereotypesOnTypes(seen, stereotypes, element);
return stereotypes;
}
private void collectStereotypesOnAnnotations(Set<Element> seen, Set<String> stereotypes, Element element) {
for (AnnotationMirror annotation : this.typeHelper.getAllAnnotationMirrors(element)) {
Element next = collectStereotypes(seen, stereotypes, element, annotation);
if (next != null) {
collectStereotypesOnAnnotations(seen, stereotypes, next);
}
}
}
private void collectStereotypesOnTypes(Set<Element> seen, Set<String> stereotypes, Element type) {
if (!seen.contains(type)) {
seen.add(type);
if (isAnnotatedWithIndexed(type)) {
stereotypes.add(this.typeHelper.getType(type));
}
Element superClass = this.typeHelper.getSuperClass(type);
if (superClass != null) {
collectStereotypesOnTypes(seen, stereotypes, superClass);
}
this.typeHelper.getDirectInterfaces(type).forEach(
i -> collectStereotypesOnTypes(seen, stereotypes, i));
}
}
private Element collectStereotypes(Set<Element> seen, Set<String> stereotypes, Element element,
AnnotationMirror annotation) {
if (isIndexedAnnotation(annotation)) {
stereotypes.add(this.typeHelper.getType(element));
}
return getCandidateAnnotationElement(seen, annotation);
}
private Element getCandidateAnnotationElement(Set<Element> seen, AnnotationMirror annotation) {
Element element = annotation.getAnnotationType().asElement();
if (seen.contains(element)) {
return null;
}
// We need to visit all indexed annotations.
if (!isIndexedAnnotation(annotation)) {
seen.add(element);
}
return (!element.toString().startsWith("java.lang") ? element : null);
}
private boolean isAnnotatedWithIndexed(Element type) {
for (AnnotationMirror annotation : type.getAnnotationMirrors()) {
if (isIndexedAnnotation(annotation)) {
return true;
}
}
return false;
}
private boolean isIndexedAnnotation(AnnotationMirror annotation) {
return INDEXED_ANNOTATION.equals(annotation.getAnnotationType().toString());
}
}