Package org.axonframework.common.annotation

Class AnnotationUtils

java.lang.Object

org.axonframework.common.annotation.AnnotationUtils

public final class AnnotationUtils
extends Object

Utility class for locating annotation and attribute values on elements.

Since:

3.0

Author:

Allard Buijze

Field Summary

Fields

Modifier and Type	Field	Description
static final boolean	ADD_ALL	Boolean specifying that a findAnnotationAttributes(AnnotatedElement, String, boolean) invocation should contain all attributes of the target annotation recursively taken into account attributes of other annotations the target is present on.
static final boolean	OVERRIDE_ONLY	Boolean specifying that a findAnnotationAttributes(AnnotatedElement, String, boolean) invocation should only contain the exact attributes of the target annotation, overridden by identical attributes on meta-annotated annotations.

Method Summary

Modifier and Type	Method	Description
static <T> Optional<T>	findAnnotationAttribute(AnnotatedElement element, Class<? extends Annotation> annotationType, String attributeName)	Find the attributeName of an annotation of type annotationType on the given element.
static Optional<Map<String,Object>>	findAnnotationAttributes(AnnotatedElement element, Class<? extends Annotation> annotationType)	Find the attributes of an annotation of type annotationType on the given element.
static Optional<Map<String,Object>>	findAnnotationAttributes(AnnotatedElement element, Class<? extends Annotation> annotationType, boolean overrideOnly)	Find the attributes of an annotation of type annotationType on the given element.
static Optional<Map<String,Object>>	findAnnotationAttributes(AnnotatedElement element, String annotationName)	Find the attributes of an annotation with given annotationName on the given element.
static Optional<Map<String,Object>>	findAnnotationAttributes(AnnotatedElement element, String annotationName, boolean overrideOnly)	Find the attributes of an annotation with given annotationName on the given element.
static Optional<Map<String,Object>>	findAnnotationAttributesOnType(Class<?> type, Class<? extends Annotation> annotationType, Predicate<Map<String,Object>> expectedAttributes)	Find the attributes of an annotation of type annotationType on the given type, following a layered search strategy.
static Predicate<Member>	isAnnotatedWith(Class<? extends Annotation> annotationType)	Creates a Predicate that checks whether the given Member is annotated with the given annotationType.
static boolean	isAnnotatedWith(Class<? extends Annotation> target, Class<? extends Annotation> subject, Set<Class<? extends Annotation>> annotatedWithSubject, Set<Class<? extends Annotation>> visited)	Validate whether the given target annotation Class is meta-annotated with the given subject.
static boolean	isAnnotationPresent(AnnotatedElement element, Class<? extends Annotation> annotationType)	Indicates whether an annotation of given annotationType is present on the given element, considering that the given annotationType may be present as a meta annotation on any other annotation on that element.
static boolean	isAnnotationPresent(AnnotatedElement element, String annotationType)	Indicates whether an annotation with given annotationType is present on the given element, considering that the given annotationType may be present as a meta annotation on any other annotation on that element.
static Predicate<Object>	isTypeAnnotatedWith(Class<? extends Annotation> annotationType)	Returns a predicate testing if a type of the given instance is annotated with provided annotation type.
static Predicate<Object>	isTypeAnnotatedWithHavingAttributeValue(Class<? extends Annotation> annotationType, String attributeName, @Nullable Object value)	Returns a predicate testing id a type of given instance us annotated with provided annotation type having a single attribute value equals to the provided one.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

OVERRIDE_ONLY

public static final boolean OVERRIDE_ONLY

Boolean specifying that a findAnnotationAttributes(AnnotatedElement, String, boolean) invocation should only contain the exact attributes of the target annotation, overridden by identical attributes on meta-annotated annotations.

See Also:

• Constant Field Values

ADD_ALL

public static final boolean ADD_ALL

Boolean specifying that a findAnnotationAttributes(AnnotatedElement, String, boolean) invocation should contain all attributes of the target annotation recursively taken into account attributes of other annotations the target is present on.

See Also:

• Constant Field Values

Method Details

isAnnotationPresent

public static boolean isAnnotationPresent(AnnotatedElement element,
 Class<? extends Annotation> annotationType)

Indicates whether an annotation of given annotationType is present on the given element, considering that the given annotationType may be present as a meta annotation on any other annotation on that element.

Parameters:

element - The element to inspect

annotationType - The type of annotation to find

Returns:

true if such annotation is present.

isAnnotationPresent

public static boolean isAnnotationPresent(AnnotatedElement element,
 String annotationType)

Indicates whether an annotation with given annotationType is present on the given element, considering that the given annotationType may be present as a meta annotation on any other annotation on that element.

Parameters:

element - The element to inspect

annotationType - The name of the annotation to find

Returns:

true if such annotation is present.

findAnnotationAttributes

public static Optional<Map<String,Object>> findAnnotationAttributes(AnnotatedElement element,
 Class<? extends Annotation> annotationType)

Find the attributes of an annotation of type annotationType on the given element. The returned optional has a value present if the annotation has been found, either directly on the element, or as a meta-annotation.

The map of attributes contains all the attributes found on the annotation, as well as attributes of any annotations on which the targeted annotation was placed (directly, or indirectly).

Note that the value property of annotations is reported as the simple class name (lowercase first character) of the annotation. This allows specific attribute overrides for annotations that have multiple meta-annotation with the value property.

Parameters:

element - The element for find the annotation on

annotationType - The type of the annotation to find

Returns:

an optional that resolved to a map with attribute names and value, if the annotation is found

findAnnotationAttributes

public static Optional<Map<String,Object>> findAnnotationAttributes(AnnotatedElement element,
 Class<? extends Annotation> annotationType,
 boolean overrideOnly)

Find the attributes of an annotation of type annotationType on the given element. The returned optional has a value present if the annotation has been found, either directly on the element, or as a meta-annotation.

The map of attributes contains all the attributes found on the annotation. The overrideOnly parameter defines whether all attributes of any annotation on which the targeted annotation was placed (directly, or indirectly) should be included. For OVERRIDE_ONLY, only attribute overrides will be added on top of that, whereas for ADD_ALL all attributes on any meta-annotated level will be included in the result.

Note that the value property of annotations is reported as the simple class name (lowercase first character) of the annotation. This allows specific attribute overrides for annotations that have multiple meta-annotation with the value property.

Parameters:

element - the element for find the annotation on

annotationType - the type of the annotation to find

overrideOnly - boolean defining whether or not to only take attribute overrides from meta-annotations into account for the result or to include all attributes from every level

Returns:

an optional that resolved to a map with attribute names and value, if the annotation is found

findAnnotationAttributes

public static Optional<Map<String,Object>> findAnnotationAttributes(AnnotatedElement element,
 String annotationName)

Find the attributes of an annotation with given annotationName on the given element. The returned optional has a value present if the annotation has been found, either directly on the element, or as a meta-annotation.

The map of attributes contains all the attributes found on the annotation, as well as attributes of any annotations on which the targeted annotation was placed (directly, or indirectly).

Parameters:

element - The element for find the annotation on

annotationName - The name of the annotation to find

Returns:

an optional that resolved to a map with attribute names and value, if the annotation is found

findAnnotationAttributes

public static Optional<Map<String,Object>> findAnnotationAttributes(AnnotatedElement element,
 String annotationName,
 boolean overrideOnly)

Find the attributes of an annotation with given annotationName on the given element. The returned optional has a value present if the annotation has been found, either directly on the element, or as a meta-annotation.

The map of attributes contains all the attributes found on the annotation. The overrideOnly parameter defines whether all attributes of any annotation on which the targeted annotation was placed (directly, or indirectly) should be included. For OVERRIDE_ONLY, only attribute overrides will be added on top of that, whereas for ADD_ALL all attributes on any meta-annotated level will be included in the result.

Note that the value property of annotations is reported as the simple class name (lowercase first character) of the annotation. This allows specific attribute overrides for annotations that have multiple meta-annotation with the value property.

Parameters:

element - the element for find the annotation on

annotationName - the name of the annotation to find

overrideOnly - boolean defining whether or not to only take attribute overrides from meta-annotations into account for the result or to include all attributes from every level

Returns:

an optional that resolved to a map with attribute names and value, if the annotation is found

findAnnotationAttribute

public static <T> Optional<T> findAnnotationAttribute(AnnotatedElement element,
 Class<? extends Annotation> annotationType,
 String attributeName)

Find the attributeName of an annotation of type annotationType on the given element. The returned optional has a value present if the annotation has been found, either directly on the element, or as a meta-annotation, if the named attribute exist.

Parameters:

element - the element to find the annotation on

annotationType - the type of the annotation to find

attributeName - the name of the attribute to find

Returns:

an optional that resolved to the attribute value, if the annotation is found and if the attribute exists

findAnnotationAttributesOnType

public static Optional<Map<String,Object>> findAnnotationAttributesOnType(Class<?> type,
 Class<? extends Annotation> annotationType,
 Predicate<Map<String,Object>> expectedAttributes)

Find the attributes of an annotation of type annotationType on the given type, following a layered search strategy. The search stops as soon as the expectedAttributes predicate returns true for the found attributes.

The search follows this ordering:

1. The type itself
2. The enclosing classes (from innermost to outermost) of the type
3. The package of the type
4. The module of the type

Parameters:

type - the type to search for the annotation on taking the described ordering

annotationType - the type of the annotation to find

expectedAttributes - a predicate that returns true when the desired attribute is found in the attributes map, indicating the search should stop. For example, to search until a non-empty "namespace" attribute is found: attrs -> !StringUtils.emptyOrNull((String) attrs.get("namespace"))

Returns:

an optional containing the attributes map if the annotation was found and the predicate was satisfied, or an empty optional if the annotation was not found at any level

isAnnotatedWith

public static boolean isAnnotatedWith(Class<? extends Annotation> target,
 Class<? extends Annotation> subject,
 Set<Class<? extends Annotation>> annotatedWithSubject,
 Set<Class<? extends Annotation>> visited)

Validate whether the given target annotation Class is meta-annotated with the given subject. If this is the case for the target itself or any meta-annotation on any level of the target, true will be returned.

Any Annotation classes which are directly annotated or meta-annotated with the given subject will be stored in the annotatedWithSubject Set. The visited Set is used to ignore annotations which have already been validated.

Parameters:

target - the annotation Class to validate if it is annotated with the given subject

subject - the annotation Class to check whether it is present on the given target, directly or through meta-annotations

annotatedWithSubject - a Set to store all class' in which are annotated with the subject, either directly or through meta-annotations

visited - a Set containing all annotation class' which have been visited in the process to overcome an endless validation loop

Returns:

true if the target or any meta-annotations of the target are annotated with the subject, false otherwise

isAnnotatedWith

public static Predicate<Member> isAnnotatedWith(Class<? extends Annotation> annotationType)

Creates a Predicate that checks whether the given Member is annotated with the given annotationType.

Parameters:

annotationType - The annotation type to check.

Returns:

Predicate that checks whether the given annotation is present.

isTypeAnnotatedWith

public static Predicate<Object> isTypeAnnotatedWith(Class<? extends Annotation> annotationType)

Returns a predicate testing if a type of the given instance is annotated with provided annotation type.

Parameters:

annotationType - An annotated type to check for.

Returns:

The predicate.

isTypeAnnotatedWithHavingAttributeValue

public static Predicate<Object> isTypeAnnotatedWithHavingAttributeValue(Class<? extends Annotation> annotationType,
 String attributeName,
 @Nullable Object value)

Returns a predicate testing id a type of given instance us annotated with provided annotation type having a single attribute value equals to the provided one.

Parameters:

annotationType - The annotation type to check for.

attributeName - The name of the attribute.

value - The value of the attribute.

Returns:

The predicate.