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   * Copyright (C) 2016 The Android Open Source Project
   * 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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  package java.lang.reflect;
  
  import java.lang.annotation.Annotation;
  import java.lang.annotation.AnnotationFormatError;
  import java.util.Objects;
  import libcore.reflect.AnnotatedElements;
  
  // Android-changed: Removed some references to bytecode spec below that do not
  // apply to DEX and added a note about annotation ordering.
  
  /**
   * 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>Android note: methods that return multiple annotations of different types such as
   * {@link #getAnnotations()} and {@link #getDeclaredAnnotations()} can be affected
   * by the explicit character-code ordering of annotations types specified by the DEX format.
   * Annotations of different types on a single element are not guaranteed to be returned in the order
   * they are declared in source.
   *
   * <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> is annotated by <i>A</i> in the original source.
   *
   * <li>An annotation <i>A</i> is <em>indirectly present</em> on an
   * element <i>E</i> if <i>E</i> is annotated by a container annotation
   * of <i>A</i>.
   *
   * <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 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 EnumConstantNotPresentException
   * @see 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 <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 <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 <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 <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) {
          // Android-changed: Altered method implementation for getAnnotationsByType(Class).
          // Android's annotation code is customized because of the use of the DEX format on Android
          // and code sharing with the runtime.
          // This method does not handle inherited annotations and is intended for use for
          // {@code Method}, {@code Field}, {@code Package}. The {@link Class#getAnnotationsByType}
          // is implemented explicitly. Therefore this implementation does not fulfill the documented
          // default implementation for {@link AnnotatedElement#getAnnotationsByType(Class)} but in an
          // undetectable way because Class is final.
          return AnnotatedElements.getDirectOrIndirectAnnotationsByType(this, annotationClass);
      }
  
      /**
       * 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 <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) {
          // Android-changed: Altered method implementation for getAnnotationsByType(Class).
          // Android's annotation code is customized because of the use of the DEX format on Android
          // and code sharing with the runtime.
          return AnnotatedElements.getDirectOrIndirectAnnotationsByType(this, annotationClass);
      }
  
      /**
       * 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();
  }
  