https://openjdk.java.net/ 
/*
 * Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 * questions.
 */

package java.lang.reflect;

import java.lang.annotation.Annotation;
import java.lang.annotation.AnnotationFormatError;
import java.lang.annotation.Repeatable;
import java.util.Arrays;
import java.util.LinkedHashMap;
import java.util.Map;
import java.util.Objects;
import java.util.function.Function;
import java.util.stream.Collectors;
import sun.reflect.annotation.AnnotationSupport;
import sun.reflect.annotation.AnnotationType;


Represents an annotated element of the program currently running in this
VM.  This interface allows annotations to be read reflectively.  All
annotations returned by methods in this interface are immutable and
serializable. The arrays returned by methods of this interface may be modified
by callers without affecting the arrays returned to other callers.

The getAnnotationsByType(Class<Annotation>) and getDeclaredAnnotationsByType(Class<Annotation>) methods support multiple annotations of the same type on an element. If the argument to either method is a repeatable annotation type (JLS 9.6), then the method will "look through" a container annotation (JLS 9.7), if present, and return any annotations inside the container. Container annotations may be generated at compile-time to wrap multiple annotations of the argument type. 
The terms directly present, indirectly present,
present, and associated are used throughout this
interface to describe precisely which annotations are returned by
methods:

    

  •  An annotation A is directly present on an
element E if E has a 
RuntimeVisibleAnnotations or 
RuntimeVisibleParameterAnnotations or 
RuntimeVisibleTypeAnnotations attribute, and the attribute contains A.

  • An annotation A is indirectly present on an
element E if E has a RuntimeVisibleAnnotations or RuntimeVisibleParameterAnnotations or RuntimeVisibleTypeAnnotations attribute, and A 's type is repeatable, and the attribute contains
exactly one annotation whose value element contains A and whose
type is the containing annotation type of A 's type.

  • An annotation A is present on an element E if either:

      

    • A is directly present on E; or

    • No annotation of A 's type is directly present on
E, and E is a class, and A 's type is
inheritable, and A is present on the superclass of E.

    

  • An annotation A is associated with an element E
if either:

      

    • A is directly or indirectly present on E; or

    • No annotation of A 's type is directly or indirectly
present on E, and E is a class, and A's type
is inheritable, and A is associated with the superclass of
E.

    



The table below summarizes which kind of annotation presence
different methods in this interface examine.


Overview of kind of presence detected by different AnnotatedElement methods

Kind of Presence

MethodDirectly PresentIndirectly PresentPresentAssociated

TgetAnnotation(Class<T>) X



Annotation[]getAnnotations() X



T[]getAnnotationsByType(Class<T>) X



TgetDeclaredAnnotation(Class<T>) X



Annotation[]getDeclaredAnnotations() X



T[]getDeclaredAnnotationsByType(Class<T>) XX





For an invocation of get[Declared]AnnotationsByType( Class <
T >), the order of annotations which are directly or indirectly present on an element E is computed as if indirectly present
annotations on E are directly present on E in place
of their container annotation, in the order in which they appear in
the value element of the container annotation.

There are several compatibility concerns to keep in mind if an
annotation type T is originally not repeatable and
later modified to be repeatable.
The containing annotation type for T is TC.

    

  • Modifying T to be repeatable is source and binary
compatible with existing uses of T and with existing uses
of TC.
That is, for source compatibility, source code with annotations of
type T or of type TC will still compile. For binary
compatibility, class files with annotations of type T or of
type TC (or with other kinds of uses of type T or of
type TC) will link against the modified version of T
if they linked against the earlier version.
(An annotation type TC may informally serve as an acting
containing annotation type before T is modified to be
formally repeatable. Alternatively, when T is made
repeatable, TC can be introduced as a new type.)

  • If an annotation type TC is present on an element, and
T is modified to be repeatable with TC as its
containing annotation type then:

      

    • The change to T is behaviorally compatible with respect to the get[Declared]Annotation(Class<T>) (called with an argument of T or TC) and 
get[Declared]Annotations() methods because the results of the methods will not change due to TC becoming the containing
annotation type for T.

    • The change to T changes the results of the 
get[Declared]AnnotationsByType(Class<T>) methods called with an argument of T, because those methods will now recognize an
annotation of type TC as a container annotation for T
and will "look through" it to expose annotations of type T.

    

  • If an annotation of type T is present on an
element and T is made repeatable and more annotations of
type T are added to the element:

      

    •  The addition of the annotations of type T is both
source compatible and binary compatible.

    • The addition of the annotations of type T changes the results of the get[Declared]Annotation(Class<T>) methods and 
get[Declared]Annotations() methods, because those methods will now only see a container annotation on the element and not see an annotation of type T.

    • The addition of the annotations of type T changes the results of the get[Declared]AnnotationsByType(Class<T>) methods, because their results will expose the additional annotations of type T whereas previously they exposed only a
single annotation of type T.

    



If an annotation returned by a method in this interface contains (directly or indirectly) a Class-valued member referring to a class that is not accessible in this VM, attempting to read the class by calling the relevant Class-returning method on the returned annotation will result in a TypeNotPresentException. 
Similarly, attempting to read an enum-valued member will result in a EnumConstantNotPresentException if the enum constant in the annotation is no longer present in the enum type. 
If an annotation type T is (meta-)annotated with an @Repeatable annotation whose value element indicates a type TC, but TC does not declare a value() method with a return type of T[], then an exception of type AnnotationFormatError is thrown. 
Finally, attempting to read a member whose definition has evolved incompatibly will result in a AnnotationTypeMismatchException or an IncompleteAnnotationException. 
Author:Josh Bloch
See Also:
Since:1.5
/**
 * Represents an annotated element of the program currently running in this
 * VM.  This interface allows annotations to be read reflectively.  All
 * annotations returned by methods in this interface are immutable and
 * serializable. The arrays returned by methods of this interface may be modified
 * by callers without affecting the arrays returned to other callers.
 *
 * <p>The {@link #getAnnotationsByType(Class)} and {@link
 * #getDeclaredAnnotationsByType(Class)} methods support multiple
 * annotations of the same type on an element. If the argument to
 * either method is a repeatable annotation type (JLS 9.6), then the
 * method will "look through" a container annotation (JLS 9.7), if
 * present, and return any annotations inside the container. Container
 * annotations may be generated at compile-time to wrap multiple
 * annotations of the argument type.
 *
 * <p>The terms <em>directly present</em>, <em>indirectly present</em>,
 * <em>present</em>, and <em>associated</em> are used throughout this
 * interface to describe precisely which annotations are returned by
 * methods:
 *
 * <ul>
 *
 * <li> An annotation <i>A</i> is <em>directly present</em> on an
 * element <i>E</i> if <i>E</i> has a {@code
 * RuntimeVisibleAnnotations} or {@code
 * RuntimeVisibleParameterAnnotations} or {@code
 * RuntimeVisibleTypeAnnotations} attribute, and the attribute
 * contains <i>A</i>.
 *
 * <li>An annotation <i>A</i> is <em>indirectly present</em> on an
 * element <i>E</i> if <i>E</i> has a {@code RuntimeVisibleAnnotations} or
 * {@code RuntimeVisibleParameterAnnotations} or {@code RuntimeVisibleTypeAnnotations}
 * attribute, and <i>A</i> 's type is repeatable, and the attribute contains
 * exactly one annotation whose value element contains <i>A</i> and whose
 * type is the containing annotation type of <i>A</i> 's type.
 *
 * <li>An annotation <i>A</i> is present on an element <i>E</i> if either:
 *
 * <ul>
 *
 * <li><i>A</i> is directly present on <i>E</i>; or
 *
 * <li>No annotation of <i>A</i> 's type is directly present on
 * <i>E</i>, and <i>E</i> is a class, and <i>A</i> 's type is
 * inheritable, and <i>A</i> is present on the superclass of <i>E</i>.
 *
 * </ul>
 *
 * <li>An annotation <i>A</i> is <em>associated</em> with an element <i>E</i>
 * if either:
 *
 * <ul>
 *
 * <li><i>A</i> is directly or indirectly present on <i>E</i>; or
 *
 * <li>No annotation of <i>A</i> 's type is directly or indirectly
 * present on <i>E</i>, and <i>E</i> is a class, and <i>A</i>'s type
 * is inheritable, and <i>A</i> is associated with the superclass of
 * <i>E</i>.
 *
 * </ul>
 *
 * </ul>
 *
 * <p>The table below summarizes which kind of annotation presence
 * different methods in this interface examine.
 *
 * <table border>
 * <caption>Overview of kind of presence detected by different AnnotatedElement methods</caption>
 * <tr><th colspan=2></th><th colspan=4>Kind of Presence</th>
 * <tr><th colspan=2>Method</th><th>Directly Present</th><th>Indirectly Present</th><th>Present</th><th>Associated</th>
 * <tr><td align=right>{@code T}</td><td>{@link #getAnnotation(Class) getAnnotation(Class&lt;T&gt;)}
 * <td></td><td></td><td>X</td><td></td>
 * </tr>
 * <tr><td align=right>{@code Annotation[]}</td><td>{@link #getAnnotations getAnnotations()}
 * <td></td><td></td><td>X</td><td></td>
 * </tr>
 * <tr><td align=right>{@code T[]}</td><td>{@link #getAnnotationsByType(Class) getAnnotationsByType(Class&lt;T&gt;)}
 * <td></td><td></td><td></td><td>X</td>
 * </tr>
 * <tr><td align=right>{@code T}</td><td>{@link #getDeclaredAnnotation(Class) getDeclaredAnnotation(Class&lt;T&gt;)}
 * <td>X</td><td></td><td></td><td></td>
 * </tr>
 * <tr><td align=right>{@code Annotation[]}</td><td>{@link #getDeclaredAnnotations getDeclaredAnnotations()}
 * <td>X</td><td></td><td></td><td></td>
 * </tr>
 * <tr><td align=right>{@code T[]}</td><td>{@link #getDeclaredAnnotationsByType(Class) getDeclaredAnnotationsByType(Class&lt;T&gt;)}
 * <td>X</td><td>X</td><td></td><td></td>
 * </tr>
 * </table>
 *
 * <p>For an invocation of {@code get[Declared]AnnotationsByType( Class <
 * T >)}, the order of annotations which are directly or indirectly
 * present on an element <i>E</i> is computed as if indirectly present
 * annotations on <i>E</i> are directly present on <i>E</i> in place
 * of their container annotation, in the order in which they appear in
 * the value element of the container annotation.
 *
 * <p>There are several compatibility concerns to keep in mind if an
 * annotation type <i>T</i> is originally <em>not</em> repeatable and
 * later modified to be repeatable.
 *
 * The containing annotation type for <i>T</i> is <i>TC</i>.
 *
 * <ul>
 *
 * <li>Modifying <i>T</i> to be repeatable is source and binary
 * compatible with existing uses of <i>T</i> and with existing uses
 * of <i>TC</i>.
 *
 * That is, for source compatibility, source code with annotations of
 * type <i>T</i> or of type <i>TC</i> will still compile. For binary
 * compatibility, class files with annotations of type <i>T</i> or of
 * type <i>TC</i> (or with other kinds of uses of type <i>T</i> or of
 * type <i>TC</i>) will link against the modified version of <i>T</i>
 * if they linked against the earlier version.
 *
 * (An annotation type <i>TC</i> may informally serve as an acting
 * containing annotation type before <i>T</i> is modified to be
 * formally repeatable. Alternatively, when <i>T</i> is made
 * repeatable, <i>TC</i> can be introduced as a new type.)
 *
 * <li>If an annotation type <i>TC</i> is present on an element, and
 * <i>T</i> is modified to be repeatable with <i>TC</i> as its
 * containing annotation type then:
 *
 * <ul>
 *
 * <li>The change to <i>T</i> is behaviorally compatible with respect
 * to the {@code get[Declared]Annotation(Class<T>)} (called with an
 * argument of <i>T</i> or <i>TC</i>) and {@code
 * get[Declared]Annotations()} methods because the results of the
 * methods will not change due to <i>TC</i> becoming the containing
 * annotation type for <i>T</i>.
 *
 * <li>The change to <i>T</i> changes the results of the {@code
 * get[Declared]AnnotationsByType(Class<T>)} methods called with an
 * argument of <i>T</i>, because those methods will now recognize an
 * annotation of type <i>TC</i> as a container annotation for <i>T</i>
 * and will "look through" it to expose annotations of type <i>T</i>.
 *
 * </ul>
 *
 * <li>If an annotation of type <i>T</i> is present on an
 * element and <i>T</i> is made repeatable and more annotations of
 * type <i>T</i> are added to the element:
 *
 * <ul>
 *
 * <li> The addition of the annotations of type <i>T</i> is both
 * source compatible and binary compatible.
 *
 * <li>The addition of the annotations of type <i>T</i> changes the results
 * of the {@code get[Declared]Annotation(Class<T>)} methods and {@code
 * get[Declared]Annotations()} methods, because those methods will now
 * only see a container annotation on the element and not see an
 * annotation of type <i>T</i>.
 *
 * <li>The addition of the annotations of type <i>T</i> changes the
 * results of the {@code get[Declared]AnnotationsByType(Class<T>)}
 * methods, because their results will expose the additional
 * annotations of type <i>T</i> whereas previously they exposed only a
 * single annotation of type <i>T</i>.
 *
 * </ul>
 *
 * </ul>
 *
 * <p>If an annotation returned by a method in this interface contains
 * (directly or indirectly) a {@link Class}-valued member referring to
 * a class that is not accessible in this VM, attempting to read the class
 * by calling the relevant Class-returning method on the returned annotation
 * will result in a {@link TypeNotPresentException}.
 *
 * <p>Similarly, attempting to read an enum-valued member will result in
 * a {@link EnumConstantNotPresentException} if the enum constant in the
 * annotation is no longer present in the enum type.
 *
 * <p>If an annotation type <i>T</i> is (meta-)annotated with an
 * {@code @Repeatable} annotation whose value element indicates a type
 * <i>TC</i>, but <i>TC</i> does not declare a {@code value()} method
 * with a return type of <i>T</i>{@code []}, then an exception of type
 * {@link java.lang.annotation.AnnotationFormatError} is thrown.
 *
 * <p>Finally, attempting to read a member whose definition has evolved
 * incompatibly will result in a {@link
 * java.lang.annotation.AnnotationTypeMismatchException} or an
 * {@link java.lang.annotation.IncompleteAnnotationException}.
 *
 * @see java.lang.EnumConstantNotPresentException
 * @see java.lang.TypeNotPresentException
 * @see AnnotationFormatError
 * @see java.lang.annotation.AnnotationTypeMismatchException
 * @see java.lang.annotation.IncompleteAnnotationException
 * @since 1.5
 * @author Josh Bloch
 */
public interface AnnotatedElement {
    
Returns true if an annotation for the specified type
is present on this element, else false.  This method
is designed primarily for convenient access to marker annotations.

The truth value returned by this method is equivalent to: getAnnotation(annotationClass) != null 
The body of the default method is specified to be the code
above.

Params:
  • annotationClass – the Class object corresponding to the
       annotation type
Throws:
Returns:true if an annotation for the specified annotation
    type is present on this element, else false
Since:1.5
/**
     * Returns true if an annotation for the specified type
     * is <em>present</em> on this element, else false.  This method
     * is designed primarily for convenient access to marker annotations.
     *
     * <p>The truth value returned by this method is equivalent to:
     * {@code getAnnotation(annotationClass) != null}
     *
     * <p>The body of the default method is specified to be the code
     * above.
     *
     * @param annotationClass the Class object corresponding to the
     *        annotation type
     * @return true if an annotation for the specified annotation
     *     type is present on this element, else false
     * @throws NullPointerException if the given annotation class is null
     * @since 1.5
     */
    default boolean isAnnotationPresent(Class<? extends Annotation> annotationClass) {
        return getAnnotation(annotationClass) != null;
    }

   
Returns this element's annotation for the specified type if
such an annotation is present, else null.

Params:
  • annotationClass – the Class object corresponding to the
       annotation type
Type parameters:
  • <T> – the type of the annotation to query for and return if present
Throws:
Returns:this element's annotation for the specified annotation type if
    present on this element, else null
Since:1.5
/**
     * Returns this element's annotation for the specified type if
     * such an annotation is <em>present</em>, else null.
     *
     * @param <T> the type of the annotation to query for and return if present
     * @param annotationClass the Class object corresponding to the
     *        annotation type
     * @return this element's annotation for the specified annotation type if
     *     present on this element, else null
     * @throws NullPointerException if the given annotation class is null
     * @since 1.5
     */
    <T extends Annotation> T getAnnotation(Class<T> annotationClass);

    
Returns annotations that are present on this element.
If there are no annotations present on this element, the return
value is an array of length 0.
The caller of this method is free to modify the returned array; it will
have no effect on the arrays returned to other callers.

Returns:annotations present on this element
Since:1.5
/**
     * Returns annotations that are <em>present</em> on this element.
     *
     * If there are no annotations <em>present</em> on this element, the return
     * value is an array of length 0.
     *
     * The caller of this method is free to modify the returned array; it will
     * have no effect on the arrays returned to other callers.
     *
     * @return annotations present on this element
     * @since 1.5
     */
    Annotation[] getAnnotations();

    
Returns annotations that are associated with this element.
If there are no annotations associated with this element, the return value is an array of length 0. The difference between this method and getAnnotation(Class<Annotation>) is that this method detects if its argument is a repeatable
annotation type (JLS 9.6), and if so, attempts to find one or
more annotations of that type by "looking through" a container
annotation.
The caller of this method is free to modify the returned array; it will
have no effect on the arrays returned to other callers.

Params:
  • annotationClass – the Class object corresponding to the
       annotation type
Type parameters:
  • <T> – the type of the annotation to query for and return if present
Throws:
Implementation Requirements:The default implementation first calls getDeclaredAnnotationsByType(Class<Annotation>) passing 
annotationClass as the argument. If the returned array has length greater than zero, the array is returned. If the returned array is zero-length and this AnnotatedElement is a class and the argument type is an inheritable annotation type, and the superclass of this AnnotatedElement is non-null, then the returned result is the result of calling getAnnotationsByType(Class<Annotation>) on the superclass with 
annotationClass as the argument. Otherwise, a zero-length array is returned.
Returns:all this element's annotations for the specified annotation type if
    associated with this element, else an array of length zero
Since:1.8
/**
     * Returns annotations that are <em>associated</em> with this element.
     *
     * If there are no annotations <em>associated</em> with this element, the return
     * value is an array of length 0.
     *
     * The difference between this method and {@link #getAnnotation(Class)}
     * is that this method detects if its argument is a <em>repeatable
     * annotation type</em> (JLS 9.6), and if so, attempts to find one or
     * more annotations of that type by "looking through" a container
     * annotation.
     *
     * The caller of this method is free to modify the returned array; it will
     * have no effect on the arrays returned to other callers.
     *
     * @implSpec The default implementation first calls {@link
     * #getDeclaredAnnotationsByType(Class)} passing {@code
     * annotationClass} as the argument. If the returned array has
     * length greater than zero, the array is returned. If the returned
     * array is zero-length and this {@code AnnotatedElement} is a
     * class and the argument type is an inheritable annotation type,
     * and the superclass of this {@code AnnotatedElement} is non-null,
     * then the returned result is the result of calling {@link
     * #getAnnotationsByType(Class)} on the superclass with {@code
     * annotationClass} as the argument. Otherwise, a zero-length
     * array is returned.
     *
     * @param <T> the type of the annotation to query for and return if present
     * @param annotationClass the Class object corresponding to the
     *        annotation type
     * @return all this element's annotations for the specified annotation type if
     *     associated with this element, else an array of length zero
     * @throws NullPointerException if the given annotation class is null
     * @since 1.8
     */
    default <T extends Annotation> T[] getAnnotationsByType(Class<T> annotationClass) {
         /*
          * Definition of associated: directly or indirectly present OR
          * neither directly nor indirectly present AND the element is
          * a Class, the annotation type is inheritable, and the
          * annotation type is associated with the superclass of the
          * element.
          */
         T[] result = getDeclaredAnnotationsByType(annotationClass);

         if (result.length == 0 && // Neither directly nor indirectly present
             this instanceof Class && // the element is a class
             AnnotationType.getInstance(annotationClass).isInherited()) { // Inheritable
             Class<?> superClass = ((Class<?>) this).getSuperclass();
             if (superClass != null) {
                 // Determine if the annotation is associated with the
                 // superclass
                 result = superClass.getAnnotationsByType(annotationClass);
             }
         }

         return result;
     }

    
Returns this element's annotation for the specified type if
such an annotation is directly present, else null.
This method ignores inherited annotations. (Returns null if no
annotations are directly present on this element.)

Params:
  • annotationClass – the Class object corresponding to the
       annotation type
Type parameters:
  • <T> – the type of the annotation to query for and return if directly present
Throws:
Implementation Requirements:The default implementation first performs a null check and then loops over the results of getDeclaredAnnotations returning the first annotation whose annotation type matches the argument type.
Returns:this element's annotation for the specified annotation type if
    directly present on this element, else null
Since:1.8
/**
     * Returns this element's annotation for the specified type if
     * such an annotation is <em>directly present</em>, else null.
     *
     * This method ignores inherited annotations. (Returns null if no
     * annotations are directly present on this element.)
     *
     * @implSpec The default implementation first performs a null check
     * and then loops over the results of {@link
     * #getDeclaredAnnotations} returning the first annotation whose
     * annotation type matches the argument type.
     *
     * @param <T> the type of the annotation to query for and return if directly present
     * @param annotationClass the Class object corresponding to the
     *        annotation type
     * @return this element's annotation for the specified annotation type if
     *     directly present on this element, else null
     * @throws NullPointerException if the given annotation class is null
     * @since 1.8
     */
    default <T extends Annotation> T getDeclaredAnnotation(Class<T> annotationClass) {
         Objects.requireNonNull(annotationClass);
         // Loop over all directly-present annotations looking for a matching one
         for (Annotation annotation : getDeclaredAnnotations()) {
             if (annotationClass.equals(annotation.annotationType())) {
                 // More robust to do a dynamic cast at runtime instead
                 // of compile-time only.
                 return annotationClass.cast(annotation);
             }
         }
         return null;
     }

    
Returns this element's annotation(s) for the specified type if
such annotations are either directly present or
indirectly present. This method ignores inherited annotations. If there are no specified annotations directly or indirectly present on this element, the return value is an array of length 0. The difference between this method and getDeclaredAnnotation(Class<Annotation>) is that this method detects if its argument is a repeatable annotation type (JLS 9.6), and if so,
attempts to find one or more annotations of that type by "looking
through" a container annotation if one is present.
The caller of this method is free to modify the returned array; it will
have no effect on the arrays returned to other callers.

Params:
  • annotationClass – the Class object corresponding to the
       annotation type
Type parameters:
  • <T> – the type of the annotation to query for and return
if directly or indirectly present
Throws:
Implementation Requirements:The default implementation may call getDeclaredAnnotation(Class<Annotation>) one or more times to find a directly present annotation and, if the annotation type is repeatable, to find a container annotation. If annotations of the annotation type annotationClass are found to be both directly and indirectly present, then getDeclaredAnnotations() will get called to determine the order of the elements in the returned array. 
Alternatively, the default implementation may call getDeclaredAnnotations() a single time and the returned array examined for both directly and indirectly present annotations. The results of calling getDeclaredAnnotations() are assumed to be consistent with the results of calling getDeclaredAnnotation(Class<Annotation>).
Returns:all this element's annotations for the specified annotation type if
    directly or indirectly present on this element, else an array of length zero
Since:1.8
/**
     * Returns this element's annotation(s) for the specified type if
     * such annotations are either <em>directly present</em> or
     * <em>indirectly present</em>. This method ignores inherited
     * annotations.
     *
     * If there are no specified annotations directly or indirectly
     * present on this element, the return value is an array of length
     * 0.
     *
     * The difference between this method and {@link
     * #getDeclaredAnnotation(Class)} is that this method detects if its
     * argument is a <em>repeatable annotation type</em> (JLS 9.6), and if so,
     * attempts to find one or more annotations of that type by "looking
     * through" a container annotation if one is present.
     *
     * The caller of this method is free to modify the returned array; it will
     * have no effect on the arrays returned to other callers.
     *
     * @implSpec The default implementation may call {@link
     * #getDeclaredAnnotation(Class)} one or more times to find a
     * directly present annotation and, if the annotation type is
     * repeatable, to find a container annotation. If annotations of
     * the annotation type {@code annotationClass} are found to be both
     * directly and indirectly present, then {@link
     * #getDeclaredAnnotations()} will get called to determine the
     * order of the elements in the returned array.
     *
     * <p>Alternatively, the default implementation may call {@link
     * #getDeclaredAnnotations()} a single time and the returned array
     * examined for both directly and indirectly present
     * annotations. The results of calling {@link
     * #getDeclaredAnnotations()} are assumed to be consistent with the
     * results of calling {@link #getDeclaredAnnotation(Class)}.
     *
     * @param <T> the type of the annotation to query for and return
     * if directly or indirectly present
     * @param annotationClass the Class object corresponding to the
     *        annotation type
     * @return all this element's annotations for the specified annotation type if
     *     directly or indirectly present on this element, else an array of length zero
     * @throws NullPointerException if the given annotation class is null
     * @since 1.8
     */
    default <T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass) {
        Objects.requireNonNull(annotationClass);
        return AnnotationSupport.
            getDirectlyAndIndirectlyPresent(Arrays.stream(getDeclaredAnnotations()).
                                            collect(Collectors.toMap(Annotation::annotationType,
                                                                     Function.identity(),
                                                                     ((first,second) -> first),
                                                                     LinkedHashMap::new)),
                                            annotationClass);
    }

    
Returns annotations that are directly present on this element.
This method ignores inherited annotations.
If there are no annotations directly present on this element,
the return value is an array of length 0.
The caller of this method is free to modify the returned array; it will
have no effect on the arrays returned to other callers.

Returns:annotations directly present on this element
Since:1.5
/**
     * Returns annotations that are <em>directly present</em> on this element.
     * This method ignores inherited annotations.
     *
     * If there are no annotations <em>directly present</em> on this element,
     * the return value is an array of length 0.
     *
     * The caller of this method is free to modify the returned array; it will
     * have no effect on the arrays returned to other callers.
     *
     * @return annotations directly present on this element
     * @since 1.5
     */
    Annotation[] getDeclaredAnnotations();
}