org.springframework.core.type.filter.AnnotationTypeFilter Maven / Gradle / Ivy
/*
* 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.type.filter;
import java.lang.annotation.Annotation;
import java.lang.annotation.Inherited;
import org.springframework.core.annotation.AnnotationUtils;
import org.springframework.core.type.AnnotationMetadata;
import org.springframework.core.type.classreading.MetadataReader;
import org.springframework.lang.Nullable;
import org.springframework.util.ClassUtils;
/**
* A simple {@link TypeFilter} which matches classes with a given annotation,
* checking inherited annotations as well.
*
* By default, the matching logic mirrors that of
* {@link AnnotationUtils#getAnnotation(java.lang.reflect.AnnotatedElement, Class)},
* supporting annotations that are present or meta-present for a
* single level of meta-annotations. The search for meta-annotations may be disabled.
* Similarly, the search for annotations on interfaces may optionally be enabled.
* Consult the various constructors in this class for details.
*
* @author Mark Fisher
* @author Ramnivas Laddad
* @author Juergen Hoeller
* @author Sam Brannen
* @since 2.5
*/
public class AnnotationTypeFilter extends AbstractTypeHierarchyTraversingFilter {
private final Class annotationType;
private final boolean considerMetaAnnotations;
/**
* Create a new {@code AnnotationTypeFilter} for the given annotation type.
*
The filter will also match meta-annotations. To disable the
* meta-annotation matching, use the constructor that accepts a
* '{@code considerMetaAnnotations}' argument.
*
The filter will not match interfaces.
* @param annotationType the annotation type to match
*/
public AnnotationTypeFilter(Class annotationType) {
this(annotationType, true, false);
}
/**
* Create a new {@code AnnotationTypeFilter} for the given annotation type.
*
The filter will not match interfaces.
* @param annotationType the annotation type to match
* @param considerMetaAnnotations whether to also match on meta-annotations
*/
public AnnotationTypeFilter(Class annotationType, boolean considerMetaAnnotations) {
this(annotationType, considerMetaAnnotations, false);
}
/**
* Create a new {@code AnnotationTypeFilter} for the given annotation type.
* @param annotationType the annotation type to match
* @param considerMetaAnnotations whether to also match on meta-annotations
* @param considerInterfaces whether to also match interfaces
*/
public AnnotationTypeFilter(
Class annotationType, boolean considerMetaAnnotations, boolean considerInterfaces) {
super(annotationType.isAnnotationPresent(Inherited.class), considerInterfaces);
this.annotationType = annotationType;
this.considerMetaAnnotations = considerMetaAnnotations;
}
/**
* Return the {@link Annotation} that this instance is using to filter
* candidates.
* @since 5.0
*/
public final Class getAnnotationType() {
return this.annotationType;
}
@Override
protected boolean matchSelf(MetadataReader metadataReader) {
AnnotationMetadata metadata = metadataReader.getAnnotationMetadata();
return metadata.hasAnnotation(this.annotationType.getName()) ||
(this.considerMetaAnnotations && metadata.hasMetaAnnotation(this.annotationType.getName()));
}
@Override
@Nullable
protected Boolean matchSuperClass(String superClassName) {
return hasAnnotation(superClassName);
}
@Override
@Nullable
protected Boolean matchInterface(String interfaceName) {
return hasAnnotation(interfaceName);
}
@Nullable
protected Boolean hasAnnotation(String typeName) {
if (Object.class.getName().equals(typeName)) {
return false;
}
else if (typeName.startsWith("java")) {
if (!this.annotationType.getName().startsWith("java")) {
// Standard Java types do not have non-standard annotations on them ->
// skip any load attempt, in particular for Java language interfaces.
return false;
}
try {
Class clazz = ClassUtils.forName(typeName, getClass().getClassLoader());
return ((this.considerMetaAnnotations ? AnnotationUtils.getAnnotation(clazz, this.annotationType) :
clazz.getAnnotation(this.annotationType)) != null);
}
catch (Throwable ex) {
// Class not regularly loadable - can't determine a match that way.
}
}
return null;
}
}