io.appulse.utils

Class AnnotationUtils

java.lang.Object

io.appulse.utils.AnnotationUtils

public final class AnnotationUtils
extends Object

Different annotation helpers.

Since:

1.7.0

Author:

Artem Labazin

Method Summary

Modifier and Type	Method and Description
static <T extends Annotation> Optional<T>	findAnnotation(AnnotatedElement annotatedElement, Class<T> annotationType) Find a single Annotation of annotationType on the supplied AnnotatedElement.
static <T extends Annotation> Optional<T>	findAnnotation(Class<?> clazz, Class<T> annotationType) Find a single Annotation of annotationType on the supplied Class, traversing its interfaces, annotations, and superclasses if the annotation is not directly present on the given class itself.
static <T extends Annotation> Optional<T>	findAnnotation(Method method, Class<T> annotationType) Find a single Annotation of annotationType on the supplied Method, traversing its super methods (i.e., from superclasses and interfaces) if the annotation is not directly present on the given method itself.
static boolean	isInJavaLangAnnotationPackage(Annotation annotation) Determine if the supplied Annotation is defined in the core JDK java.lang.annotation package.
static boolean	isInJavaLangAnnotationPackage(Class<? extends Annotation> annotationType) Determine if the Annotation with the supplied name is defined in the core JDK java.lang.annotation package.
static boolean	isInJavaLangAnnotationPackage(String annotationType) Determine if the Annotation with the supplied name is defined in the core JDK java.lang.annotation package.

Methods inherited from class java.lang.Object

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

Method Detail

findAnnotation

public static <T extends Annotation> Optional<T> findAnnotation(Class<?> clazz,
                                                                Class<T> annotationType)

Find a single Annotation of annotationType on the supplied Class, traversing its interfaces, annotations, and superclasses if the annotation is not directly present on the given class itself.

This method explicitly handles class-level annotations which are not declared as inherited as well as meta-annotations and annotations on interfaces.

The algorithm operates as follows:

1. Search for the annotation on the given class and return it if found.
2. Recursively search through all annotations that the given class declares.
3. Recursively search through all interfaces that the given class declares.
4. Recursively search through the superclass hierarchy of the given class.

Note: in this context, the term recursively 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.

Parameters:

clazz - the class to look for annotations on

annotationType - the annotation type to look for, both locally and as a meta-annotation

Returns:

the first matching annotation

Since:

1.7.0

findAnnotation

public static <T extends Annotation> Optional<T> findAnnotation(AnnotatedElement annotatedElement,
                                                                Class<T> annotationType)

Find a single Annotation of annotationType on the supplied AnnotatedElement.

Meta-annotations will be searched if the annotation is not directly present on the supplied element.

Warning: 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 findAnnotation(Class, Class) or findAnnotation(Method, Class), invoke one of those methods instead.

Parameters:

annotatedElement - the AnnotatedElement on which to find the annotation

annotationType - the annotation type to look for, both locally and as a meta-annotation

Returns:

the first matching annotation

Since:

1.7.0

findAnnotation

public static <T extends Annotation> Optional<T> findAnnotation(Method method,
                                                                Class<T> annotationType)

Find a single Annotation of annotationType on the supplied Method, traversing its super methods (i.e., from superclasses and interfaces) if the annotation is not directly present on the given method itself.

Correctly handles bridge Methods generated by the compiler.

Meta-annotations will be searched if the annotation is not directly present on the method.

Annotations on methods are not inherited by default, so we need to handle this explicitly.

Parameters:

method - the method to look for annotations on

annotationType - the annotation type to look for

Returns:

the first matching annotation

Since:

1.7.0

isInJavaLangAnnotationPackage

public static boolean isInJavaLangAnnotationPackage(Annotation annotation)

Determine if the supplied Annotation is defined in the core JDK java.lang.annotation package.

Parameters:

annotation - the annotation to check

Returns:

true if the annotation is in the java.lang.annotation package

Since:

1.7.0

isInJavaLangAnnotationPackage

public static boolean isInJavaLangAnnotationPackage(Class<? extends Annotation> annotationType)

Determine if the Annotation with the supplied name is defined in the core JDK java.lang.annotation package.

Parameters:

annotationType - the annotation type to check

Returns:

true if the annotation is in the java.lang.annotation package

Since:

1.7.0

isInJavaLangAnnotationPackage

public static boolean isInJavaLangAnnotationPackage(String annotationType)

Determine if the Annotation with the supplied name is defined in the core JDK java.lang.annotation package.

Parameters:

annotationType - the name of the annotation type to check

Returns:

true if the annotation is in the java.lang.annotation package

Since:

1.7.0