package com.github.valdr.thirdparty.spring;
/*
* This class was copied and modified from the Spring framework. Thanks!
*/
/*
* Copyright 2002-2013 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.
*/
import java.lang.annotation.Annotation;
import java.lang.reflect.AnnotatedElement;
import java.lang.reflect.Method;
import java.util.List;
import java.util.Map;
import java.util.WeakHashMap;
/**
* General utility methods for working with annotations, handling bridge methods (which the compiler
* generates for generic declarations) as well as super methods (for optional "annotation inheritance").
* Note that none of this is provided by the JDK's introspection facilities themselves.
*
* <p>As a general rule for runtime-retained annotations (e.g. for transaction control, authorization or service
* exposure), always use the lookup methods on this class (e.g., {@code #findAnnotation(java.lang.reflect.Method,
* Class)}, {@code
* #getAnnotation(java.lang.reflect.Method, Class)}, and {@code #getAnnotations(java.lang.reflect.Method)}) instead of
* the plain annotation lookup
* methods in the JDK. You can still explicitly choose between lookup on the given class level only ({@code
* #getAnnotation(java.lang.reflect.Method, Class)}) and lookup in the entire inheritance hierarchy of the given method ({@link
* #findAnnotation(java.lang.reflect.Method, Class)}).
*
* @author Rob Harrop
* @author Juergen Hoeller
* @author Sam Brannen
* @author Mark Fisher
* @author Chris Beams
* @since 2.0
* @see java.lang.reflect.Method#getAnnotations()
* @see java.lang.reflect.Method#getAnnotation(Class)
*/
public abstract class AnnotationUtils {
/** The attribute name for annotations with a single element */
static final String VALUE = "value";
private static final Map<Class<?>, Boolean> annotatedInterfaceCache = new WeakHashMap<Class<?>, Boolean>();
/**
* Get a single {@link java.lang.annotation.Annotation} of {@code annotationType} from the supplied
* Method, Constructor or Field. Meta-annotations will be searched if the annotation
* is not declared locally on the supplied element.
* @param ae the Method, Constructor or Field from which to get the annotation
* @param annotationType the annotation class to look for, both locally and as a meta-annotation
* @param <T> annotation type
* @return the matching annotation or {@code null} if not found
* @since 3.1
*/
public static <T extends Annotation> T getAnnotation(AnnotatedElement ae, Class<T> annotationType) {
T ann = ae.getAnnotation(annotationType);
if (ann == null) {
for (Annotation metaAnn : ae.getAnnotations()) {
ann = metaAnn.annotationType().getAnnotation(annotationType);
if (ann != null) {
break;
}
}
}
return ann;
}
/**
* Get a single {@link java.lang.annotation.Annotation} of {@code annotationType} from the supplied {@link java.lang.reflect.Method},
* traversing its super methods if no annotation can be found on the given method itself.
* <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 class to look for
* @param <A> annotation type
* @return the annotation found, or {@code null} if none found
*/
public static <A extends Annotation> A findAnnotation(Method method, Class<A> annotationType) {
A annotation = getAnnotation(method, annotationType);
Class<?> clazz = method.getDeclaringClass();
if (annotation == null) {
annotation = searchOnInterfaces(method, annotationType, clazz.getInterfaces());
}
while (annotation == null) {
clazz = clazz.getSuperclass();
if (clazz == null || clazz.equals(Object.class)) {
break;
}
try {
Method equivalentMethod = clazz.getDeclaredMethod(method.getName(), method.getParameterTypes());
annotation = getAnnotation(equivalentMethod, annotationType);
}
catch (NoSuchMethodException ex) {
// No equivalent method found
}
if (annotation == null) {
annotation = searchOnInterfaces(method, annotationType, clazz.getInterfaces());
}
}
return annotation;
}
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;
}
private static boolean isInterfaceWithAnnotatedMethods(Class<?> iface) {
synchronized (annotatedInterfaceCache) {
Boolean flag = annotatedInterfaceCache.get(iface);
if (flag != null) {
return flag;
}
boolean found = false;
for (Method ifcMethod : iface.getMethods()) {
if (ifcMethod.getAnnotations().length > 0) {
found = true;
break;
}
}
annotatedInterfaceCache.put(iface, found);
return found;
}
}
/**
* Find a single {@link java.lang.annotation.Annotation} of {@code annotationType} from the supplied {@link Class},
* traversing its interfaces and superclasses if no annotation can be found on the given class itself.
* <p>This method explicitly handles class-level annotations which are not declared as
* {@link java.lang.annotation.Inherited inherited} <i>as well as annotations on interfaces</i>.
* <p>The algorithm operates as follows: Searches for an annotation on the given class and returns
* it if found. Else searches all interfaces that the given class declares, returning the annotation
* from the first matching candidate, if any. Else proceeds with introspection of the superclass
* of the given class, checking the superclass itself; if no annotation found there, proceeds
* with the interfaces that the superclass declares. Recursing up through the entire superclass
* hierarchy if no match is found.
* @param clazz the class to look for annotations on
* @param annotationType the annotation class to look for
* @param <A> annotation type
* @return the annotation found, or {@code null} if none found
*/
public static <A extends Annotation> A findAnnotation(Class<?> clazz, Class<A> annotationType) {
A annotation = clazz.getAnnotation(annotationType);
if (annotation != null) {
return annotation;
}
for (Class<?> ifc : clazz.getInterfaces()) {
annotation = findAnnotation(ifc, annotationType);
if (annotation != null) {
return annotation;
}
}
if (!Annotation.class.isAssignableFrom(clazz)) {
for (Annotation ann : clazz.getAnnotations()) {
annotation = findAnnotation(ann.annotationType(), annotationType);
if (annotation != null) {
return annotation;
}
}
}
Class<?> superClass = clazz.getSuperclass();
if (superClass == null || superClass.equals(Object.class)) {
return null;
}
return findAnnotation(superClass, annotationType);
}
/**
* Find the first {@link Class} in the inheritance hierarchy of the specified {@code clazz}
* (including the specified {@code clazz} itself) which declares an annotation for the
* specified {@code annotationType}, or {@code null} if not found. If the supplied
* {@code clazz} is {@code null}, {@code null} will be returned.
* <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>The standard {@link Class} API does not provide a mechanism for determining which class
* in an inheritance hierarchy actually declares an {@link java.lang.annotation.Annotation}, so we need to handle
* this explicitly.
* @param annotationType the Class object corresponding to the annotation type
* @param clazz the Class object corresponding to the class on which to check for the annotation,
* or {@code null}
* @return the first {@link Class} in the inheritance hierarchy of the specified {@code clazz}
* which declares an annotation for the specified {@code annotationType}, or {@code null}
* if not found
* @see Class#isAnnotationPresent(Class)
* @see Class#getDeclaredAnnotations()
* @see #findAnnotationDeclaringClassForTypes(java.util.List, Class)
* @see #isAnnotationDeclaredLocally(Class, Class)
*/
public static Class<?> findAnnotationDeclaringClass(Class<? extends Annotation> annotationType, Class<?> clazz) {
if (clazz == null || clazz.equals(Object.class)) {
return null;
}
return (isAnnotationDeclaredLocally(annotationType, clazz)) ? clazz : findAnnotationDeclaringClass(
annotationType, clazz.getSuperclass());
}
/**
* Find the first {@link Class} in the inheritance hierarchy of the specified
* {@code clazz} (including the specified {@code clazz} itself) which declares
* at least one of the specified {@code annotationTypes}, or {@code null} if
* none of the specified annotation types could be found.
* <p>If the supplied {@code clazz} is {@code null}, {@code null} will be
* returned.
* <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>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 java.lang.annotation.Annotation annotations}, so we need to handle this
* explicitly.
* @param annotationTypes the list of Class objects corresponding to the
* annotation types
* @param clazz the Class object corresponding to the class on which to check
* for the annotations, or {@code null}
* @return the first {@link Class} in the inheritance hierarchy of the specified
* {@code clazz} which declares an annotation of at least one of the specified
* {@code annotationTypes}, or {@code null} if not found
* @since 3.2.2
* @see Class#isAnnotationPresent(Class)
* @see Class#getDeclaredAnnotations()
* @see #findAnnotationDeclaringClass(Class, Class)
* @see #isAnnotationDeclaredLocally(Class, Class)
*/
public static Class<?> findAnnotationDeclaringClassForTypes(List<Class<? extends Annotation>> annotationTypes, Class<?> clazz) {
if (clazz == null || clazz.equals(Object.class)) {
return null;
}
for (Class<? extends Annotation> annotationType : annotationTypes) {
if (isAnnotationDeclaredLocally(annotationType, clazz)) {
return clazz;
}
}
return findAnnotationDeclaringClassForTypes(annotationTypes, clazz.getSuperclass());
}
/**
* Determine whether an annotation for the specified {@code annotationType} is
* declared locally on the supplied {@code clazz}. The supplied {@link Class}
* may represent any type.
* <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 Class object corresponding to the annotation type
* @param clazz the Class object corresponding to the class on which to check for the annotation
* @return {@code true} if an annotation for the specified {@code annotationType}
* is declared locally on the supplied {@code clazz}
* @see Class#getDeclaredAnnotations()
* @see #isAnnotationInherited(Class, Class)
*/
public static boolean isAnnotationDeclaredLocally(Class<? extends Annotation> annotationType, Class<?> clazz) {
boolean declaredLocally = false;
for (Annotation annotation : clazz.getDeclaredAnnotations()) {
if (annotation.annotationType().equals(annotationType)) {
declaredLocally = true;
break;
}
}
return declaredLocally;
}
/**
* Determine whether an annotation for the specified {@code annotationType} is present
* on the supplied {@code clazz} and is {@linkplain java.lang.annotation.Inherited inherited}
* (i.e., not declared locally for the class).
* <p>If the supplied {@code clazz} is an interface, only the interface itself will be checked.
* In accordance with standard meta-annotation semantics, 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 Class object corresponding to the annotation type
* @param clazz the Class object corresponding to the class on which to check for the annotation
* @return {@code true} if an annotation for the specified {@code annotationType} is present
* on the supplied {@code clazz} and is <em>inherited</em>
* @see Class#isAnnotationPresent(Class)
* @see #isAnnotationDeclaredLocally(Class, Class)
*/
public static boolean isAnnotationInherited(Class<? extends Annotation> annotationType, Class<?> clazz) {
return (clazz.isAnnotationPresent(annotationType) && !isAnnotationDeclaredLocally(annotationType, clazz));
}
/**
* Retrieve the given annotation's attributes as a Map, preserving all attribute types
* as-is.
* <p>Note: As of Spring 3.1.1, the returned map is actually an
* {@code org.springframework.core.annotation.AnnotationAttributes} instance, however the Map signature of this
* methodhas
* 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
*/
public static Map<String, Object> getAnnotationAttributes(Annotation annotation) {
return getAnnotationAttributes(annotation, false, false);
}
/**
* Retrieve the given annotation's attributes as a Map. Equivalent to calling
* {@link #getAnnotationAttributes(java.lang.annotation.Annotation, boolean, boolean)} with
* the {@code nestedAnnotationsAsMap} parameter set to {@code false}.
* <p>Note: As of Spring 3.1.1, the returned map is actually an
* {@code org.springframework.core.annotation.AnnotationAttributes} instance, however the Map signature of this
* methodhas
* been preserved for binary compatibility.
* @param annotation the annotation to retrieve the attributes for
* @param classValuesAsString whether to turn Class references into Strings (for
* compatibility with {@code org.springframework.core.type.AnnotationMetadata} or to
* preserve them as Class references
* @return the Map of annotation attributes, with attribute names as keys and
* corresponding attribute values as values
*/
public static Map<String, Object> getAnnotationAttributes(Annotation annotation, boolean classValuesAsString) {
return getAnnotationAttributes(annotation, classValuesAsString, false);
}
/**
* Retrieve the given annotation's attributes as an {@code org.springframework.core.annotation.AnnotationAttributes}
* map structure. Implemented in Spring 3.1.1 to provide fully recursive annotation
* reading capabilities on par with that of the reflection-based
* {@code org.springframework.core.type.StandardAnnotationMetadata}.
* @param annotation the annotation to retrieve the attributes for
* @param classValuesAsString whether to turn Class references into Strings (for
* compatibility with {@code org.springframework.core.type.AnnotationMetadata} or to
* preserve them as Class references
* @param nestedAnnotationsAsMap whether to turn nested Annotation instances into
* {@code org.springframework.core.annotation.AnnotationAttributes} maps (for compatibility with
* {@code org.springframework.core.type.AnnotationMetadata} or to preserve them as
* Annotation instances
* @return the annotation attributes (a specialized Map) with attribute names as keys
* and corresponding attribute values as values
* @since 3.1.1
*/
public static AnnotationAttributes getAnnotationAttributes(Annotation annotation, boolean classValuesAsString,
boolean nestedAnnotationsAsMap) {
AnnotationAttributes attrs = new AnnotationAttributes();
Method[] methods = annotation.annotationType().getDeclaredMethods();
for (Method method : methods) {
if (method.getParameterTypes().length == 0 && method.getReturnType() != void.class) {
try {
Object value = method.invoke(annotation);
if (classValuesAsString) {
if (value instanceof Class) {
value = ((Class<?>) value).getName();
}
else if (value instanceof Class[]) {
Class<?>[] clazzArray = (Class[]) value;
String[] newValue = new String[clazzArray.length];
for (int i = 0; i < clazzArray.length; i++) {
newValue[i] = clazzArray[i].getName();
}
value = newValue;
}
}
if (nestedAnnotationsAsMap && value instanceof Annotation) {
attrs.put(method.getName(),
getAnnotationAttributes((Annotation) value, classValuesAsString, nestedAnnotationsAsMap));
}
else if (nestedAnnotationsAsMap && value instanceof Annotation[]) {
Annotation[] realAnnotations = (Annotation[]) value;
AnnotationAttributes[] mappedAnnotations = new AnnotationAttributes[realAnnotations.length];
for (int i = 0; i < realAnnotations.length; i++) {
mappedAnnotations[i] = getAnnotationAttributes(realAnnotations[i], classValuesAsString,
nestedAnnotationsAsMap);
}
attrs.put(method.getName(), mappedAnnotations);
}
else {
attrs.put(method.getName(), value);
}
}
catch (Exception ex) {
throw new IllegalStateException("Could not obtain annotation attribute values", ex);
}
}
}
return attrs;
}
/**
* 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(java.lang.annotation.Annotation, String)
*/
public static Object getValue(Annotation annotation) {
return getValue(annotation, VALUE);
}
/**
* Retrieve the <em>value</em> of a named Annotation 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(java.lang.annotation.Annotation)
*/
public static Object getValue(Annotation annotation, String attributeName) {
try {
Method method = annotation.annotationType().getDeclaredMethod(attributeName, new Class[0]);
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(java.lang.annotation.Annotation, String)
*/
public static Object getDefaultValue(Annotation annotation) {
return getDefaultValue(annotation, VALUE);
}
/**
* Retrieve the <em>default value</em> of a named Annotation 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) {
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 Annotation 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(java.lang.annotation.Annotation, String)
*/
public static Object getDefaultValue(Class<? extends Annotation> annotationType, String attributeName) {
try {
Method method = annotationType.getDeclaredMethod(attributeName, new Class[0]);
return method.getDefaultValue();
}
catch (Exception ex) {
return null;
}
}
}
