package ltd.beihu.core.tools.utils;
import ltd.beihu.core.tools.annotation.AnnotationAttributes;
import ltd.beihu.core.tools.annotation.BridgeMethodResolver;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.lang.annotation.Annotation;
import java.lang.annotation.Repeatable;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.*;
import java.util.concurrent.ConcurrentHashMap;
public class AnnotationUtils {
/**
* The attribute name for annotations with a single element.
*/
public static final String VALUE = "value";
private static final Map<AnnotationCacheKey, Annotation> findAnnotationCache =
new ConcurrentHashMap<>(256);
private static final Map<AnnotationCacheKey, Boolean> metaPresentCache =
new ConcurrentHashMap<>(256);
private static final Map<Class<?>, Boolean> annotatedInterfaceCache =
new ConcurrentHashMap<>(256);
private static final Map<Class<? extends Annotation>, Boolean> synthesizableCache =
new ConcurrentHashMap<>(256);
private static final Map<Class<? extends Annotation>, Map<String, List<String>>> attributeAliasesCache =
new ConcurrentHashMap<>(256);
private static final Map<Class<? extends Annotation>, List<Method>> attributeMethodsCache =
new ConcurrentHashMap<>(256);
private static transient Logger logger;
/**
* Get a single {@link Annotation} of {@code annotationType} from the supplied
* annotation: either the given annotation itself or a direct meta-annotation
* thereof.
* <p>Note that this method supports only a single level of meta-annotations.
* For support for arbitrary levels of meta-annotations, use one of the
* {@code find*()} methods instead.
*
* @param ann the Annotation to check
* @param annotationType the annotation type to look for, both locally and as a meta-annotation
* @return the first matching annotation, or {@code null} if not found
* @since 4.0
*/
@SuppressWarnings("unchecked")
public static <A extends Annotation> A getAnnotation(Annotation ann, Class<A> annotationType) {
if (annotationType.isInstance(ann)) {
return (A) ann;
}
Class<? extends Annotation> annotatedElement = ann.annotationType();
try {
return findAnnotation(ann.getClass(), annotationType);
} catch (Throwable ex) {
handleIntrospectionFailure(annotatedElement, ex);
}
return null;
}
/**
* Get a single {@link Annotation} of {@code annotationType} from the supplied
* {@link AnnotatedElement}, where the annotation is either <em>present</em> or
* <em>meta-present</em> on the {@code AnnotatedElement}.
* <p>Note that this method supports only a single level of meta-annotations.
* For support for arbitrary levels of meta-annotations, use
* {@link #findAnnotation(AnnotatedElement, Class)} instead.
*
* @param annotatedElement the {@code AnnotatedElement} from which to get the annotation
* @param annotationType the annotation type to look for, both locally and as a meta-annotation
* @return the first matching annotation, or {@code null} if not found
* @since 3.1
*/
public static <A extends Annotation> A getAnnotation(AnnotatedElement annotatedElement, Class<A> annotationType) {
try {
A annotation = annotatedElement.getAnnotation(annotationType);
if (annotation == null) {
for (Annotation metaAnn : annotatedElement.getAnnotations()) {
annotation = metaAnn.annotationType().getAnnotation(annotationType);
if (annotation != null) {
break;
}
}
}
return annotation;
} catch (Throwable ex) {
handleIntrospectionFailure(annotatedElement, ex);
}
return null;
}
/**
* Get a single {@link Annotation} of {@code annotationType} from the
* supplied {@link Method}, where the annotation is either <em>present</em>
* or <em>meta-present</em> on the method.
* <p>Correctly handles bridge {@link Method Methods} generated by the compiler.
* <p>Note that this method supports only a single level of meta-annotations.
* For support for arbitrary levels of meta-annotations, use
* {@link #findAnnotation(Method, Class)} instead.
*
* @param method the method to look for annotations on
* @param annotationType the annotation type to look for
* @return the first matching annotation, or {@code null} if not found
* @see #getAnnotation(AnnotatedElement, Class)
*/
public static <A extends Annotation> A getAnnotation(Method method, Class<A> annotationType) {
Method resolvedMethod = BridgeMethodResolver.findBridgedMethod(method);
return getAnnotation((AnnotatedElement) resolvedMethod, annotationType);
}
/**
* Get all {@link Annotation Annotations} that are <em>present</em> on the
* supplied {@link AnnotatedElement}.
* <p>Meta-annotations will <em>not</em> be searched.
*
* @param annotatedElement the Method, Constructor or Field to retrieve annotations from
* @return the annotations found, an empty array, or {@code null} if not
* resolvable (e.g. because nested Class values in annotation attributes
* failed to resolve at runtime)
* @see AnnotatedElement#getAnnotations()
* @since 4.0.8
*/
public static Annotation[] getAnnotations(AnnotatedElement annotatedElement) {
try {
return annotatedElement.getAnnotations();
} catch (Throwable ex) {
handleIntrospectionFailure(annotatedElement, ex);
}
return null;
}
/**
* Get all {@link Annotation Annotations} that are <em>present</em> on the
* supplied {@link Method}.
* <p>Correctly handles bridge {@link Method Methods} generated by the compiler.
* <p>Meta-annotations will <em>not</em> be searched.
*
* @param method the Method to retrieve annotations from
* @return the annotations found, an empty array, or {@code null} if not
* resolvable (e.g. because nested Class values in annotation attributes
* failed to resolve at runtime)
* @see AnnotatedElement#getAnnotations()
*/
public static Annotation[] getAnnotations(Method method) {
try {
return method.getAnnotations();
} catch (Throwable ex) {
handleIntrospectionFailure(method, ex);
}
return null;
}
/**
* Get the <em>repeatable</em> {@linkplain Annotation annotations} of
* {@code annotationType} from the supplied {@link AnnotatedElement}, where
* such annotations are either <em>present</em>, <em>indirectly present</em>,
* or <em>meta-present</em> on the element.
* <p>This method mimics the functionality of Java 8's
* {@link AnnotatedElement#getAnnotationsByType(Class)}
* with support for automatic detection of a <em>container annotation</em>
* declared via @{@link Repeatable} (when running on
* Java 8 or higher) and with additional support for meta-annotations.
* <p>Handles both single annotations and annotations nested within a
* <em>container annotation</em>.
* <p>Correctly handles <em>bridge methods</em> generated by the
* compiler if the supplied element is a {@link Method}.
* <p>Meta-annotations will be searched if the annotation is not
* <em>present</em> on the supplied element.
*
* @param annotatedElement the element to look for annotations on
* @param annotationType the annotation type to look for
* @return the annotations found or an empty set (never {@code null})
* @see #getRepeatableAnnotations(AnnotatedElement, Class, Class)
* @see #getDeclaredRepeatableAnnotations(AnnotatedElement, Class, Class)
* @see Repeatable
* @see AnnotatedElement#getAnnotationsByType
* @since 4.2
*/
public static <A extends Annotation> Set<A> getRepeatableAnnotations(AnnotatedElement annotatedElement,
Class<A> annotationType) {
return getRepeatableAnnotations(annotatedElement, annotationType, null);
}
/**
* Get the <em>repeatable</em> {@linkplain Annotation annotations} of
* {@code annotationType} from the supplied {@link AnnotatedElement}, where
* such annotations are either <em>present</em>, <em>indirectly present</em>,
* or <em>meta-present</em> on the element.
* <p>This method mimics the functionality of Java 8's
* {@link AnnotatedElement#getAnnotationsByType(Class)}
* with additional support for meta-annotations.
* <p>Handles both single annotations and annotations nested within a
* <em>container annotation</em>.
* <p>Correctly handles <em>bridge methods</em> generated by the
* compiler if the supplied element is a {@link Method}.
* <p>Meta-annotations will be searched if the annotation is not
* <em>present</em> on the supplied element.
*
* @param annotatedElement the element to look for annotations on
* @param annotationType the annotation type to look for
* @param containerAnnotationType the type of the container that holds
* the annotations; may be {@code null} if a container is not supported
* or if it should be looked up via @{@link Repeatable}
* when running on Java 8 or higher
* @return the annotations found or an empty set (never {@code null})
* @see #getRepeatableAnnotations(AnnotatedElement, Class)
* @see #getDeclaredRepeatableAnnotations(AnnotatedElement, Class)
* @see #getDeclaredRepeatableAnnotations(AnnotatedElement, Class, Class)
* @see Repeatable
* @see AnnotatedElement#getAnnotationsByType
* @since 4.2
*/
public static <A extends Annotation> Set<A> getRepeatableAnnotations(AnnotatedElement annotatedElement,
Class<A> annotationType, Class<? extends Annotation> containerAnnotationType) {
Set<A> annotations = getDeclaredRepeatableAnnotations(annotatedElement, annotationType, containerAnnotationType);
if (!annotations.isEmpty()) {
return annotations;
}
if (annotatedElement instanceof Class) {
Class<?> superclass = ((Class<?>) annotatedElement).getSuperclass();
if (superclass != null && Object.class != superclass) {
return getRepeatableAnnotations(superclass, annotationType, containerAnnotationType);
}
}
return getRepeatableAnnotations(annotatedElement, annotationType, containerAnnotationType, false);
}
/**
* Get the declared <em>repeatable</em> {@linkplain Annotation annotations}
* of {@code annotationType} from the supplied {@link AnnotatedElement},
* where such annotations are either <em>directly present</em>,
* <em>indirectly present</em>, or <em>meta-present</em> on the element.
* <p>This method mimics the functionality of Java 8's
* {@link AnnotatedElement#getDeclaredAnnotationsByType(Class)}
* with support for automatic detection of a <em>container annotation</em>
* declared via @{@link Repeatable} (when running on
* Java 8 or higher) and with additional support for meta-annotations.
* <p>Handles both single annotations and annotations nested within a
* <em>container annotation</em>.
* <p>Correctly handles <em>bridge methods</em> generated by the
* compiler if the supplied element is a {@link Method}.
* <p>Meta-annotations will be searched if the annotation is not
* <em>present</em> on the supplied element.
*
* @param annotatedElement the element to look for annotations on
* @param annotationType the annotation type to look for
* @return the annotations found or an empty set (never {@code null})
* @see #getRepeatableAnnotations(AnnotatedElement, Class)
* @see #getRepeatableAnnotations(AnnotatedElement, Class, Class)
* @see #getDeclaredRepeatableAnnotations(AnnotatedElement, Class, Class)
* @see Repeatable
* @see AnnotatedElement#getDeclaredAnnotationsByType
* @since 4.2
*/
public static <A extends Annotation> Set<A> getDeclaredRepeatableAnnotations(AnnotatedElement annotatedElement,
Class<A> annotationType) {
return getDeclaredRepeatableAnnotations(annotatedElement, annotationType, null);
}
/**
* Get the declared <em>repeatable</em> {@linkplain Annotation annotations}
* of {@code annotationType} from the supplied {@link AnnotatedElement},
* where such annotations are either <em>directly present</em>,
* <em>indirectly present</em>, or <em>meta-present</em> on the element.
* <p>This method mimics the functionality of Java 8's
* {@link AnnotatedElement#getDeclaredAnnotationsByType(Class)}
* with additional support for meta-annotations.
* <p>Handles both single annotations and annotations nested within a
* <em>container annotation</em>.
* <p>Correctly handles <em>bridge methods</em> generated by the
* compiler if the supplied element is a {@link Method}.
* <p>Meta-annotations will be searched if the annotation is not
* <em>present</em> on the supplied element.
*
* @param annotatedElement the element to look for annotations on
* @param annotationType the annotation type to look for
* @param containerAnnotationType the type of the container that holds
* the annotations; may be {@code null} if a container is not supported
* or if it should be looked up via @{@link Repeatable}
* when running on Java 8 or higher
* @return the annotations found or an empty set (never {@code null})
* @see #getRepeatableAnnotations(AnnotatedElement, Class)
* @see #getRepeatableAnnotations(AnnotatedElement, Class, Class)
* @see #getDeclaredRepeatableAnnotations(AnnotatedElement, Class)
* @see Repeatable
* @see AnnotatedElement#getDeclaredAnnotationsByType
* @since 4.2
*/
public static <A extends Annotation> Set<A> getDeclaredRepeatableAnnotations(AnnotatedElement annotatedElement,
Class<A> annotationType, Class<? extends Annotation> containerAnnotationType) {
return getRepeatableAnnotations(annotatedElement, annotationType, containerAnnotationType, true);
}
/**
* Perform the actual work for {@link #getRepeatableAnnotations(AnnotatedElement, Class, Class)}
* and {@link #getDeclaredRepeatableAnnotations(AnnotatedElement, Class, Class)}.
* <p>Correctly handles <em>bridge methods</em> generated by the
* compiler if the supplied element is a {@link Method}.
* <p>Meta-annotations will be searched if the annotation is not
* <em>present</em> on the supplied element.
*
* @param annotatedElement the element to look for annotations on
* @param annotationType the annotation type to look for
* @param containerAnnotationType the type of the container that holds
* the annotations; may be {@code null} if a container is not supported
* or if it should be looked up via @{@link Repeatable}
* when running on Java 8 or higher
* @param declaredMode {@code true} if only declared annotations (i.e.,
* directly or indirectly present) should be considered
* @return the annotations found or an empty set (never {@code null})
* @see Repeatable
* @since 4.2
*/
private static <A extends Annotation> Set<A> getRepeatableAnnotations(AnnotatedElement annotatedElement,
Class<A> annotationType, Class<? extends Annotation> containerAnnotationType, boolean declaredMode) {
Assert.notNull(annotatedElement, "AnnotatedElement must not be null");
Assert.notNull(annotationType, "Annotation type must not be null");
try {
if (annotatedElement instanceof Method) {
annotatedElement = BridgeMethodResolver.findBridgedMethod((Method) annotatedElement);
}
return new AnnotationCollector<>(annotationType, containerAnnotationType, declaredMode).getResult(annotatedElement);
} catch (Throwable ex) {
handleIntrospectionFailure(annotatedElement, ex);
}
return Collections.emptySet();
}
/**
* Find a single {@link Annotation} of {@code annotationType} on the
* supplied {@link AnnotatedElement}.
* <p>Meta-annotations will be searched if the annotation is not
* <em>directly present</em> on the supplied element.
* <p><strong>Warning</strong>: this method operates generically on
* annotated elements. In other words, this method does not execute
* specialized search algorithms for classes or methods. If you require
* the more specific semantics of {@link #findAnnotation(Class, Class)}
* or {@link #findAnnotation(Method, Class)}, invoke one of those methods
* instead.
*
* @param annotatedElement the {@code AnnotatedElement} on which to find the annotation
* @param annotationType the annotation type to look for, both locally and as a meta-annotation
* @return the first matching annotation, or {@code null} if not found
* @since 4.2
*/
public static <A extends Annotation> A findAnnotation(AnnotatedElement annotatedElement, Class<A> annotationType) {
Assert.notNull(annotatedElement, "AnnotatedElement must not be null");
if (annotationType == null) {
return null;
}
// Do NOT store result in the findAnnotationCache since doing so could break
// findAnnotation(Class, Class) and findAnnotation(Method, Class).
A ann = findAnnotation(annotatedElement, annotationType, new HashSet<>());
return ann;
}
/**
* Perform the search algorithm for {@link #findAnnotation(AnnotatedElement, Class)}
* avoiding endless recursion by tracking which annotations have already
* been <em>visited</em>.
*
* @param annotatedElement the {@code AnnotatedElement} on which to find the annotation
* @param annotationType the annotation type to look for, both locally and as a meta-annotation
* @param visited the set of annotations that have already been visited
* @return the first matching annotation, or {@code null} if not found
* @since 4.2
*/
@SuppressWarnings("unchecked")
private static <A extends Annotation> A findAnnotation(
AnnotatedElement annotatedElement, Class<A> annotationType, Set<Annotation> visited) {
try {
Annotation[] anns = annotatedElement.getDeclaredAnnotations();
for (Annotation ann : anns) {
if (ann.annotationType() == annotationType) {
return (A) ann;
}
}
for (Annotation ann : anns) {
if (!isInJavaLangAnnotationPackage(ann) && visited.add(ann)) {
A annotation = findAnnotation((AnnotatedElement) ann.annotationType(), annotationType, visited);
if (annotation != null) {
return annotation;
}
}
}
} catch (Throwable ex) {
handleIntrospectionFailure(annotatedElement, ex);
}
return null;
}
/**
* Find a single {@link Annotation} of {@code annotationType} on the supplied
* {@link Method}, traversing its super methods (i.e., from superclasses and
* interfaces) if the annotation is not <em>directly present</em> on the given
* method itself.
* <p>Correctly handles bridge {@link Method Methods} generated by the compiler.
* <p>Meta-annotations will be searched if the annotation is not
* <em>directly present</em> on the method.
* <p>Annotations on methods are not inherited by default, so we need to handle
* this explicitly.
*
* @param method the method to look for annotations on
* @param annotationType the annotation type to look for
* @return the first matching annotation, or {@code null} if not found
* @see #getAnnotation(Method, Class)
*/
@SuppressWarnings("unchecked")
public static <A extends Annotation> A findAnnotation(Method method, Class<A> annotationType) {
Assert.notNull(method, "Method must not be null");
if (annotationType == null) {
return null;
}
AnnotationCacheKey cacheKey = new AnnotationCacheKey(method, annotationType);
A result = (A) findAnnotationCache.get(cacheKey);
if (result == null) {
Method resolvedMethod = BridgeMethodResolver.findBridgedMethod(method);
result = findAnnotation((AnnotatedElement) resolvedMethod, annotationType);
if (result == null) {
result = searchOnInterfaces(method, annotationType, method.getDeclaringClass().getInterfaces());
}
Class<?> clazz = method.getDeclaringClass();
while (result == null) {
clazz = clazz.getSuperclass();
if (clazz == null || Object.class == clazz) {
break;
}
try {
Method equivalentMethod = clazz.getDeclaredMethod(method.getName(), method.getParameterTypes());
Method resolvedEquivalentMethod = BridgeMethodResolver.findBridgedMethod(equivalentMethod);
result = findAnnotation((AnnotatedElement) resolvedEquivalentMethod, annotationType);
} catch (NoSuchMethodException ex) {
// No equivalent method found
}
if (result == null) {
result = searchOnInterfaces(method, annotationType, clazz.getInterfaces());
}
}
if (result != null) {
findAnnotationCache.put(cacheKey, result);
}
}
return result;
}
private static <A extends Annotation> A searchOnInterfaces(Method method, Class<A> annotationType, Class<?>... ifcs) {
A annotation = null;
for (Class<?> iface : ifcs) {
if (isInterfaceWithAnnotatedMethods(iface)) {
try {
Method equivalentMethod = iface.getMethod(method.getName(), method.getParameterTypes());
annotation = getAnnotation(equivalentMethod, annotationType);
} catch (NoSuchMethodException ex) {
// Skip this interface - it doesn't have the method...
}
if (annotation != null) {
break;
}
}
}
return annotation;
}
static boolean isInterfaceWithAnnotatedMethods(Class<?> iface) {
Boolean found = annotatedInterfaceCache.get(iface);
if (found != null) {
return found;
}
found = Boolean.FALSE;
for (Method ifcMethod : iface.getMethods()) {
try {
if (ifcMethod.getAnnotations().length > 0) {
found = Boolean.TRUE;
break;
}
} catch (Throwable ex) {
handleIntrospectionFailure(ifcMethod, ex);
}
}
annotatedInterfaceCache.put(iface, found);
return found;
}
/**
* Find a single {@link Annotation} of {@code annotationType} on the
* supplied {@link Class}, traversing its interfaces, annotations, and
* superclasses if the annotation is not <em>directly present</em> on
* the given class itself.
* <p>This method explicitly handles class-level annotations which are not
* declared as {@link java.lang.annotation.Inherited inherited} <em>as well
* as meta-annotations and annotations on interfaces</em>.
* <p>The algorithm operates as follows:
* <ol>
* <li>Search for the annotation on the given class and return it if found.
* <li>Recursively search through all annotations that the given class declares.
* <li>Recursively search through all interfaces that the given class declares.
* <li>Recursively search through the superclass hierarchy of the given class.
* </ol>
* <p>Note: in this context, the term <em>recursively</em> means that the search
* process continues by returning to step #1 with the current interface,
* annotation, or superclass as the class to look for annotations on.
*
* @param clazz the class to look for annotations on
* @param annotationType the type of annotation to look for
* @return the first matching annotation, or {@code null} if not found
*/
public static <A extends Annotation> A findAnnotation(Class<?> clazz, Class<A> annotationType) {
return findAnnotation(clazz, annotationType, true);
}
/**
* Perform the actual work for {@link #findAnnotation(AnnotatedElement, Class)},
* honoring the {@code synthesize} flag.
*
* @param clazz the class to look for annotations on
* @param annotationType the type of annotation to look for
* @return the first matching annotation, or {@code null} if not found
* @since 4.2.1
*/
@SuppressWarnings("unchecked")
private static <A extends Annotation> A findAnnotation(Class<?> clazz, Class<A> annotationType, boolean synthesize) {
Assert.notNull(clazz, "Class must not be null");
if (annotationType == null) {
return null;
}
AnnotationCacheKey cacheKey = new AnnotationCacheKey(clazz, annotationType);
A result = (A) findAnnotationCache.get(cacheKey);
if (result == null) {
result = findAnnotation(clazz, annotationType, new HashSet<>());
if (result != null && synthesize) {
findAnnotationCache.put(cacheKey, result);
}
}
return result;
}
/**
* Perform the search algorithm for {@link #findAnnotation(Class, Class)},
* avoiding endless recursion by tracking which annotations have already
* been <em>visited</em>.
*
* @param clazz the class to look for annotations on
* @param annotationType the type of annotation to look for
* @param visited the set of annotations that have already been visited
* @return the first matching annotation, or {@code null} if not found
*/
@SuppressWarnings("unchecked")
private static <A extends Annotation> A findAnnotation(Class<?> clazz, Class<A> annotationType, Set<Annotation> visited) {
try {
Annotation[] anns = clazz.getDeclaredAnnotations();
for (Annotation ann : anns) {
if (ann.annotationType() == annotationType) {
return (A) ann;
}
}
for (Annotation ann : anns) {
if (!isInJavaLangAnnotationPackage(ann) && visited.add(ann)) {
A annotation = findAnnotation(ann.annotationType(), annotationType, visited);
if (annotation != null) {
return annotation;
}
}
}
} catch (Throwable ex) {
handleIntrospectionFailure(clazz, ex);
return null;
}
for (Class<?> ifc : clazz.getInterfaces()) {
A annotation = findAnnotation(ifc, annotationType, visited);
if (annotation != null) {
return annotation;
}
}
Class<?> superclass = clazz.getSuperclass();
if (superclass == null || Object.class == superclass) {
return null;
}
return findAnnotation(superclass, annotationType, visited);
}
/**
* Find the first {@link Class} in the inheritance hierarchy of the
* specified {@code clazz} (including the specified {@code clazz} itself)
* on which an annotation of the specified {@code annotationType} is
* <em>directly present</em>.
* <p>If the supplied {@code clazz} is an interface, only the interface
* itself will be checked; the inheritance hierarchy for interfaces will
* not be traversed.
* <p>Meta-annotations will <em>not</em> be searched.
* <p>The standard {@link Class} API does not provide a mechanism for
* determining which class in an inheritance hierarchy actually declares
* an {@link Annotation}, so we need to handle this explicitly.
*
* @param annotationType the annotation type to look for
* @param clazz the class to check for the annotation on (may be {@code null})
* @return the first {@link Class} in the inheritance hierarchy that
* declares an annotation of the specified {@code annotationType}, or
* {@code null} if not found
* @see Class#isAnnotationPresent(Class)
* @see Class#getDeclaredAnnotations()
* @see #findAnnotationDeclaringClassForTypes(List, Class)
* @see #isAnnotationDeclaredLocally(Class, Class)
*/
public static Class<?> findAnnotationDeclaringClass(Class<? extends Annotation> annotationType, Class<?> clazz) {
Assert.notNull(annotationType, "Annotation type must not be null");
if (clazz == null || Object.class == clazz) {
return null;
}
if (isAnnotationDeclaredLocally(annotationType, clazz)) {
return clazz;
}
return findAnnotationDeclaringClass(annotationType, clazz.getSuperclass());
}
/**
* Find the first {@link Class} in the inheritance hierarchy of the
* specified {@code clazz} (including the specified {@code clazz} itself)
* on which at least one of the specified {@code annotationTypes} is
* <em>directly present</em>.
* <p>If the supplied {@code clazz} is an interface, only the interface
* itself will be checked; the inheritance hierarchy for interfaces will
* not be traversed.
* <p>Meta-annotations will <em>not</em> be searched.
* <p>The standard {@link Class} API does not provide a mechanism for
* determining which class in an inheritance hierarchy actually declares
* one of several candidate {@linkplain Annotation annotations}, so we
* need to handle this explicitly.
*
* @param annotationTypes the annotation types to look for
* @param clazz the class to check for the annotations on, or {@code null}
* @return the first {@link Class} in the inheritance hierarchy that
* declares an annotation of at least one of the specified
* {@code annotationTypes}, or {@code null} if not found
* @see Class#isAnnotationPresent(Class)
* @see Class#getDeclaredAnnotations()
* @see #findAnnotationDeclaringClass(Class, Class)
* @see #isAnnotationDeclaredLocally(Class, Class)
* @since 3.2.2
*/
public static Class<?> findAnnotationDeclaringClassForTypes(List<Class<? extends Annotation>> annotationTypes, Class<?> clazz) {
Assert.notEmpty(annotationTypes, "List of annotation types must not be empty");
if (clazz == null || Object.class == clazz) {
return null;
}
for (Class<? extends Annotation> annotationType : annotationTypes) {
if (isAnnotationDeclaredLocally(annotationType, clazz)) {
return clazz;
}
}
return findAnnotationDeclaringClassForTypes(annotationTypes, clazz.getSuperclass());
}
/**
* Determine whether an annotation of the specified {@code annotationType}
* is declared locally (i.e., <em>directly present</em>) on the supplied
* {@code clazz}.
* <p>The supplied {@link Class} may represent any type.
* <p>Meta-annotations will <em>not</em> be searched.
* <p>Note: This method does <strong>not</strong> determine if the annotation
* is {@linkplain java.lang.annotation.Inherited inherited}. For greater
* clarity regarding inherited annotations, consider using
* {@link #isAnnotationInherited(Class, Class)} instead.
*
* @param annotationType the annotation type to look for
* @param clazz the class to check for the annotation on
* @return {@code true} if an annotation of the specified {@code annotationType}
* is <em>directly present</em>
* @see Class#getDeclaredAnnotations()
* @see Class#getDeclaredAnnotation(Class)
* @see #isAnnotationInherited(Class, Class)
*/
public static boolean isAnnotationDeclaredLocally(Class<? extends Annotation> annotationType, Class<?> clazz) {
Assert.notNull(annotationType, "Annotation type must not be null");
Assert.notNull(clazz, "Class must not be null");
try {
for (Annotation ann : clazz.getDeclaredAnnotations()) {
if (ann.annotationType() == annotationType) {
return true;
}
}
} catch (Throwable ex) {
handleIntrospectionFailure(clazz, ex);
}
return false;
}
/**
* Determine whether an annotation of the specified {@code annotationType}
* is <em>present</em> on the supplied {@code clazz} and is
* {@linkplain java.lang.annotation.Inherited inherited} (i.e., not
* <em>directly present</em>).
* <p>Meta-annotations will <em>not</em> be searched.
* <p>If the supplied {@code clazz} is an interface, only the interface
* itself will be checked. In accordance with standard meta-annotation
* semantics in Java, the inheritance hierarchy for interfaces will not
* be traversed. See the {@linkplain java.lang.annotation.Inherited Javadoc}
* for the {@code @Inherited} meta-annotation for further details regarding
* annotation inheritance.
*
* @param annotationType the annotation type to look for
* @param clazz the class to check for the annotation on
* @return {@code true} if an annotation of the specified {@code annotationType}
* is <em>present</em> and <em>inherited</em>
* @see Class#isAnnotationPresent(Class)
* @see #isAnnotationDeclaredLocally(Class, Class)
*/
public static boolean isAnnotationInherited(Class<? extends Annotation> annotationType, Class<?> clazz) {
Assert.notNull(annotationType, "Annotation type must not be null");
Assert.notNull(clazz, "Class must not be null");
return (clazz.isAnnotationPresent(annotationType) && !isAnnotationDeclaredLocally(annotationType, clazz));
}
/**
* Determine if an annotation of type {@code metaAnnotationType} is
* <em>meta-present</em> on the supplied {@code annotationType}.
*
* @param annotationType the annotation type to search on
* @param metaAnnotationType the type of meta-annotation to search for
* @return {@code true} if such an annotation is meta-present
* @since 4.2.1
*/
public static boolean isAnnotationMetaPresent(Class<? extends Annotation> annotationType,
Class<? extends Annotation> metaAnnotationType) {
Assert.notNull(annotationType, "Annotation type must not be null");
if (metaAnnotationType == null) {
return false;
}
AnnotationCacheKey cacheKey = new AnnotationCacheKey(annotationType, metaAnnotationType);
Boolean metaPresent = metaPresentCache.get(cacheKey);
if (metaPresent != null) {
return metaPresent;
}
metaPresent = Boolean.FALSE;
if (findAnnotation(annotationType, metaAnnotationType, false) != null) {
metaPresent = Boolean.TRUE;
}
metaPresentCache.put(cacheKey, metaPresent);
return metaPresent;
}
/**
* Determine if the supplied {@link Annotation} is defined in the core JDK
* {@code java.lang.annotation} package.
*
* @param annotation the annotation to check
* @return {@code true} if the annotation is in the {@code java.lang.annotation} package
*/
public static boolean isInJavaLangAnnotationPackage(Annotation annotation) {
return (annotation != null && isInJavaLangAnnotationPackage(annotation.annotationType().getName()));
}
/**
* Determine if the {@link Annotation} with the supplied name is defined
* in the core JDK {@code java.lang.annotation} package.
*
* @param annotationType the name of the annotation type to check (never {@code null} or empty)
* @return {@code true} if the annotation is in the {@code java.lang.annotation} package
* @since 4.2
*/
public static boolean isInJavaLangAnnotationPackage(String annotationType) {
return (annotationType != null && annotationType.startsWith("java.lang.annotation"));
}
/**
* Retrieve the given annotation's attributes as a {@link Map}, preserving all
* attribute types.
* with the {@code classValuesAsString} and {@code nestedAnnotationsAsMap} parameters
* set to {@code false}.
* <p>Note: This method actually returns an {@link AnnotationAttributes} instance.
* However, the {@code Map} signature has been preserved for binary compatibility.
*
* @param annotation the annotation to retrieve the attributes for
* @return the Map of annotation attributes, with attribute names as keys and
* corresponding attribute values as values (never {@code null})
* @see #getAnnotationAttributes(AnnotatedElement, Annotation)
*/
public static Map<String, Object> getAnnotationAttributes(Annotation annotation) {
return getAnnotationAttributes(null, annotation);
}
/**
* Retrieve the given annotation's attributes as an {@link AnnotationAttributes} map.
* with the {@code classValuesAsString} and {@code nestedAnnotationsAsMap} parameters
* set to {@code false}.
*
* @param annotatedElement the element that is annotated with the supplied annotation;
* may be {@code null} if unknown
* @param annotation the annotation to retrieve the attributes for
* @return the annotation attributes (a specialized Map) with attribute names as keys
* and corresponding attribute values as values (never {@code null})
* @since 4.2
*/
public static AnnotationAttributes getAnnotationAttributes(AnnotatedElement annotatedElement, Annotation annotation) {
return getAnnotationAttributes(annotatedElement, annotation, false);
}
/**
* Retrieve the given annotation's attributes as an {@link AnnotationAttributes} map.
* <p>This method provides fully recursive annotation reading capabilities on par with
*
* @param annotatedElement the element that is annotated with the supplied annotation;
* may be {@code null} if unknown
* @param annotation the annotation to retrieve the attributes for
* @return the annotation attributes (a specialized Map) with attribute names as keys
* and corresponding attribute values as values (never {@code null})
* @since 4.2
*/
public static AnnotationAttributes getAnnotationAttributes(AnnotatedElement annotatedElement,
Annotation annotation, boolean classValuesAsString) {
return getAnnotationAttributes(
(Object) annotatedElement, annotation, classValuesAsString);
}
private static AnnotationAttributes getAnnotationAttributes(Object annotatedElement,
Annotation annotation, boolean classValuesAsString) {
AnnotationAttributes attributes =
retrieveAnnotationAttributes(annotatedElement, annotation, classValuesAsString);
postProcessAnnotationAttributes(annotatedElement, attributes, classValuesAsString);
return attributes;
}
/**
* Retrieve the given annotation's attributes as an {@link AnnotationAttributes} map.
* <p>This method provides fully recursive annotation reading capabilities on par with
* <p><strong>NOTE</strong>: This variant of {@code getAnnotationAttributes()} is
* only intended for use within the framework. The following special rules apply:
* <ol>
* <li>Default values will be replaced with default value placeholders.</li>
* <li>The resulting, merged annotation attributes should eventually be
* {@linkplain #postProcessAnnotationAttributes post-processed} in order to
* ensure that placeholders have been replaced by actual default values and
* in order to enforce {@code @AliasFor} semantics.</li>
* </ol>
*
* @param annotatedElement the element that is annotated with the supplied annotation;
* may be {@code null} if unknown
* @param annotation the annotation to retrieve the attributes for
* @param classValuesAsString whether to convert Class references into Strings (for
* or to preserve them as Class references
* @return the annotation attributes (a specialized Map) with attribute names as keys
* and corresponding attribute values as values (never {@code null})
* @see #postProcessAnnotationAttributes
* @since 4.2
*/
static AnnotationAttributes retrieveAnnotationAttributes(Object annotatedElement, Annotation annotation,
boolean classValuesAsString) {
Class<? extends Annotation> annotationType = annotation.annotationType();
AnnotationAttributes attributes = new AnnotationAttributes(annotationType);
for (Method method : getAttributeMethods(annotationType)) {
try {
Object attributeValue = method.invoke(annotation);
Object defaultValue = method.getDefaultValue();
if (defaultValue != null && Objects.equals(attributeValue, defaultValue)) {
attributeValue = new DefaultValueHolder(defaultValue);
}
attributes.put(method.getName(),
adaptValue(annotatedElement, attributeValue, classValuesAsString));
} catch (Throwable ex) {
if (ex instanceof InvocationTargetException) {
Throwable targetException = ((InvocationTargetException) ex).getTargetException();
rethrowAnnotationConfigurationException(targetException);
}
throw new IllegalStateException("Could not obtain annotation attribute value for " + method, ex);
}
}
return attributes;
}
/**
* Adapt the given value according to the given class and nested annotation settings.
* <p>Nested annotations will be
*
* @param annotatedElement the element that is annotated, used for contextual
* logging; may be {@code null} if unknown
* @param value the annotation attribute value
* @param classValuesAsString whether to convert Class references into Strings (for
* or to preserve them as Class references
* @return the adapted value, or the original value if no adaptation is needed
*/
static Object adaptValue(Object annotatedElement, Object value, boolean classValuesAsString) {
if (classValuesAsString) {
if (value instanceof Class) {
return ((Class<?>) value).getName();
} else if (value instanceof Class[]) {
Class<?>[] clazzArray = (Class<?>[]) value;
String[] classNames = new String[clazzArray.length];
for (int i = 0; i < clazzArray.length; i++) {
classNames[i] = clazzArray[i].getName();
}
return classNames;
}
}
if (value instanceof Annotation) {
Annotation annotation = (Annotation) value;
return getAnnotationAttributes(annotatedElement, annotation, classValuesAsString);
}
if (value instanceof Annotation[]) {
Annotation[] annotations = (Annotation[]) value;
AnnotationAttributes[] mappedAnnotations = new AnnotationAttributes[annotations.length];
for (int i = 0; i < annotations.length; i++) {
mappedAnnotations[i] =
getAnnotationAttributes(annotatedElement, annotations[i], classValuesAsString);
}
return mappedAnnotations;
}
// Fallback
return value;
}
/**
* Post-process the supplied {@link AnnotationAttributes}.
* <p>Specifically, this method enforces <em>attribute alias</em> semantics
* and replaces default value placeholders with their original default values.
*
* @param annotatedElement the element that is annotated with an annotation or
* annotation hierarchy from which the supplied attributes were created;
* may be {@code null} if unknown
* @param attributes the annotation attributes to post-process
* @param classValuesAsString whether to convert Class references into Strings (for
* or to preserve them as Class references
* @see #getDefaultValue(Class, String)
* @since 4.2
*/
static void postProcessAnnotationAttributes(Object annotatedElement,
AnnotationAttributes attributes, boolean classValuesAsString) {
// Abort?
if (attributes == null) {
return;
}
Class<? extends Annotation> annotationType = attributes.annotationType();
// Replace any remaining placeholders with actual default values
for (String attributeName : attributes.keySet()) {
Object value = attributes.get(attributeName);
if (value instanceof DefaultValueHolder) {
value = ((DefaultValueHolder) value).defaultValue;
attributes.put(attributeName,
adaptValue(annotatedElement, value, classValuesAsString));
}
}
}
/**
* Retrieve the <em>value</em> of the {@code value} attribute of a
* single-element Annotation, given an annotation instance.
*
* @param annotation the annotation instance from which to retrieve the value
* @return the attribute value, or {@code null} if not found
* @see #getValue(Annotation, String)
*/
public static Object getValue(Annotation annotation) {
return getValue(annotation, VALUE);
}
/**
* Retrieve the <em>value</em> of a named attribute, given an annotation instance.
*
* @param annotation the annotation instance from which to retrieve the value
* @param attributeName the name of the attribute value to retrieve
* @return the attribute value, or {@code null} if not found
* @see #getValue(Annotation)
*/
public static Object getValue(Annotation annotation, String attributeName) {
if (annotation == null || !StringUtils.isNotBlank(attributeName)) {
return null;
}
try {
Method method = annotation.annotationType().getDeclaredMethod(attributeName);
ReflectionHelper.makeAccessible(method);
return method.invoke(annotation);
} catch (Exception ex) {
return null;
}
}
/**
* Retrieve the <em>default value</em> of the {@code value} attribute
* of a single-element Annotation, given an annotation instance.
*
* @param annotation the annotation instance from which to retrieve the default value
* @return the default value, or {@code null} if not found
* @see #getDefaultValue(Annotation, String)
*/
public static Object getDefaultValue(Annotation annotation) {
return getDefaultValue(annotation, VALUE);
}
/**
* Retrieve the <em>default value</em> of a named attribute, given an annotation instance.
*
* @param annotation the annotation instance from which to retrieve the default value
* @param attributeName the name of the attribute value to retrieve
* @return the default value of the named attribute, or {@code null} if not found
* @see #getDefaultValue(Class, String)
*/
public static Object getDefaultValue(Annotation annotation, String attributeName) {
if (annotation == null) {
return null;
}
return getDefaultValue(annotation.annotationType(), attributeName);
}
/**
* Retrieve the <em>default value</em> of the {@code value} attribute
* of a single-element Annotation, given the {@link Class annotation type}.
*
* @param annotationType the <em>annotation type</em> for which the default value should be retrieved
* @return the default value, or {@code null} if not found
* @see #getDefaultValue(Class, String)
*/
public static Object getDefaultValue(Class<? extends Annotation> annotationType) {
return getDefaultValue(annotationType, VALUE);
}
/**
* Retrieve the <em>default value</em> of a named attribute, given the
* {@link Class annotation type}.
*
* @param annotationType the <em>annotation type</em> for which the default value should be retrieved
* @param attributeName the name of the attribute value to retrieve.
* @return the default value of the named attribute, or {@code null} if not found
* @see #getDefaultValue(Annotation, String)
*/
public static Object getDefaultValue(Class<? extends Annotation> annotationType, String attributeName) {
if (annotationType == null || !StringUtils.isNotBlank(attributeName)) {
return null;
}
try {
return annotationType.getDeclaredMethod(attributeName).getDefaultValue();
} catch (Exception ex) {
return null;
}
}
/**
* Get all methods declared in the supplied {@code annotationType} that
* match Java's requirements for annotation <em>attributes</em>.
* <p>All methods in the returned list will be
* {@linkplain ReflectionHelper#makeAccessible(Method) made accessible}.
*
* @param annotationType the type in which to search for attribute methods;
* never {@code null}
* @return all annotation attribute methods in the specified annotation
* type (never {@code null}, though potentially <em>empty</em>)
* @since 4.2
*/
static List<Method> getAttributeMethods(Class<? extends Annotation> annotationType) {
List<Method> methods = attributeMethodsCache.get(annotationType);
if (methods != null) {
return methods;
}
methods = new ArrayList<>();
for (Method method : annotationType.getDeclaredMethods()) {
if (isAttributeMethod(method)) {
ReflectionHelper.makeAccessible(method);
methods.add(method);
}
}
attributeMethodsCache.put(annotationType, methods);
return methods;
}
/**
* Get the annotation with the supplied {@code annotationName} on the
* supplied {@code element}.
*
* @param element the element to search on
* @param annotationName the fully qualified class name of the annotation
* type to find
* @return the annotation if found; {@code null} otherwise
* @since 4.2
*/
static Annotation getAnnotation(AnnotatedElement element, String annotationName) {
for (Annotation annotation : element.getAnnotations()) {
if (annotation.annotationType().getName().equals(annotationName)) {
return annotation;
}
}
return null;
}
/**
* Determine if the supplied {@code method} is an annotation attribute method.
*
* @param method the method to check
* @return {@code true} if the method is an attribute method
* @since 4.2
*/
static boolean isAttributeMethod(Method method) {
return (method != null && method.getParameterCount() == 0 && method.getReturnType() != void.class);
}
/**
* Determine if the supplied method is an "annotationType" method.
*
* @return {@code true} if the method is an "annotationType" method
* @see Annotation#annotationType()
* @since 4.2
*/
static boolean isAnnotationTypeMethod(Method method) {
return (method != null && method.getName().equals("annotationType") && method.getParameterCount() == 0);
}
/**
* Resolve the container type for the supplied repeatable {@code annotationType}.
* <p>Automatically detects a <em>container annotation</em> declared via
* {@link Repeatable}. If the supplied annotation type
* is not annotated with {@code @Repeatable}, this method simply returns
* {@code null}.
*
* @since 4.2
*/
static Class<? extends Annotation> resolveContainerAnnotationType(Class<? extends Annotation> annotationType) {
Repeatable repeatable = getAnnotation(annotationType, Repeatable.class);
return (repeatable != null ? repeatable.value() : null);
}
/**
* If the supplied throwable is an {@link},
* it will be cast to an {@code AnnotationConfigurationException} and thrown,
* allowing it to propagate to the caller.
* <p>Otherwise, this method does nothing.
*
* @param ex the throwable to inspect
* @since 4.2
*/
static void rethrowAnnotationConfigurationException(Throwable ex) {
}
/**
* Handle the supplied annotation introspection exception.
* it will simply be thrown, allowing it to propagate to the caller, and
* nothing will be logged.
* <p>Otherwise, this method logs an introspection failure (in particular
* {@code TypeNotPresentExceptions}) before moving on, assuming nested
* Class values were not resolvable within annotation attributes and
* thereby effectively pretending there were no annotations on the specified
* element.
*
* @param element the element that we tried to introspect annotations on
* @param ex the exception that we encountered
* @see #rethrowAnnotationConfigurationException
*/
static void handleIntrospectionFailure(AnnotatedElement element, Throwable ex) {
rethrowAnnotationConfigurationException(ex);
Logger loggerToUse = logger;
if (loggerToUse == null) {
loggerToUse = LoggerFactory.getLogger(AnnotationUtils.class);
logger = loggerToUse;
}
if (element instanceof Class && Annotation.class.isAssignableFrom((Class<?>) element)) {
// Meta-annotation lookup on an annotation type
if (loggerToUse.isDebugEnabled()) {
loggerToUse.debug("Failed to introspect meta-annotations on [" + element + "]: " + ex);
}
} else {
// Direct annotation lookup on regular Class, Method, Field
if (loggerToUse.isInfoEnabled()) {
loggerToUse.info("Failed to introspect annotations on [" + element + "]: " + ex);
}
}
}
/**
* Cache key for the AnnotatedElement cache.
*/
private static final class AnnotationCacheKey implements Comparable<AnnotationCacheKey> {
private final AnnotatedElement element;
private final Class<? extends Annotation> annotationType;
public AnnotationCacheKey(AnnotatedElement element, Class<? extends Annotation> annotationType) {
this.element = element;
this.annotationType = annotationType;
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (!(other instanceof AnnotationCacheKey)) {
return false;
}
AnnotationCacheKey otherKey = (AnnotationCacheKey) other;
return (this.element.equals(otherKey.element) && this.annotationType.equals(otherKey.annotationType));
}
@Override
public int hashCode() {
return (this.element.hashCode() * 29 + this.annotationType.hashCode());
}
@Override
public String toString() {
return "@" + this.annotationType + " on " + this.element;
}
@Override
public int compareTo(AnnotationCacheKey other) {
int result = this.element.toString().compareTo(other.element.toString());
if (result == 0) {
result = this.annotationType.getName().compareTo(other.annotationType.getName());
}
return result;
}
}
private static class AnnotationCollector<A extends Annotation> {
private final Class<A> annotationType;
private final Class<? extends Annotation> containerAnnotationType;
private final boolean declaredMode;
private final Set<AnnotatedElement> visited = new HashSet<>();
private final Set<A> result = new LinkedHashSet<>();
AnnotationCollector(Class<A> annotationType, Class<? extends Annotation> containerAnnotationType, boolean declaredMode) {
this.annotationType = annotationType;
this.containerAnnotationType = (containerAnnotationType != null ? containerAnnotationType :
resolveContainerAnnotationType(annotationType));
this.declaredMode = declaredMode;
}
Set<A> getResult(AnnotatedElement element) {
process(element);
return Collections.unmodifiableSet(this.result);
}
@SuppressWarnings("unchecked")
private void process(AnnotatedElement element) {
if (this.visited.add(element)) {
try {
Annotation[] annotations = (this.declaredMode ? element.getDeclaredAnnotations() : element.getAnnotations());
for (Annotation ann : annotations) {
Class<? extends Annotation> currentAnnotationType = ann.annotationType();
if (Objects.equals(this.annotationType, currentAnnotationType)) {
this.result.add((A) ann);
} else if (Objects.equals(this.containerAnnotationType, currentAnnotationType)) {
this.result.addAll(getValue(element, ann));
} else if (!isInJavaLangAnnotationPackage(ann)) {
process(currentAnnotationType);
}
}
} catch (Throwable ex) {
handleIntrospectionFailure(element, ex);
}
}
}
@SuppressWarnings("unchecked")
private List<A> getValue(AnnotatedElement element, Annotation annotation) {
try {
return new ArrayList<>(Arrays.asList((A[]) AnnotationUtils.getValue(annotation)));
} catch (Throwable ex) {
handleIntrospectionFailure(element, ex);
}
// Unable to read value from repeating annotation container -> ignore it.
return Collections.emptyList();
}
}
private static class DefaultValueHolder {
final Object defaultValue;
public DefaultValueHolder(Object defaultValue) {
this.defaultValue = defaultValue;
}
}
}
