src/share/classes/java/lang/reflect/AnnotatedElement.java
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@@ -30,67 +30,120 @@
/**
* 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. It is permissible for the caller to modify the
- * arrays returned by accessors for array-valued enum members; it will
- * have no affect on the arrays returned to other callers.
+ * 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) which was generated at
- * compile-time to wrap multiple annotations of the argument type.
- *
- * <p>The terms <em>directly present</em> and <em>present</em> are used
- * throughout this interface to describe precisely which annotations are
- * returned by methods:
+ * 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 A is <em>directly present</em> on an element E if E is
- * associated with a RuntimeVisibleAnnotations or
- * RuntimeVisibleParameterAnnotations attribute, and:
+ *
+ * <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>for an invocation of {@code get[Declared]Annotation(Class<T>)} or
- * {@code get[Declared]Annotations()}, the attribute contains A.
*
- * <li>for an invocation of {@code get[Declared]AnnotationsByType(Class<T>)}, the
- * attribute either contains A or, if the type of A is repeatable, contains
- * exactly one annotation whose value element contains A and whose type is the
- * containing annotation type of A's type (JLS 9.6).
+ * <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>
*
- * <p>
- * <li>An annotation A is <em>present</em> on an element E if either:
+ * <li>An annotation <i>A</i> is <em>associated</em> with an element <i>E</i>
+ * if either:
*
* <ul>
- * <li>A is <em>directly present</em> on E; or
*
- * <li>A is not <em>directly present</em> on E, and E is a class, and A's type
- * is inheritable (JLS 9.6.3.3), and A is <em>present</em> on the superclass of
- * E.
+ * <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></th><th colspan=4>Kind of Presence</th>
+ * <tr><th>Method</th><th>Directly Present</th><th>Indirectly Present</th><th>Present</th><th>Associated</th>
+ * <tr><td>{@link #getAnnotation(Class) T getAnnotation(Class<T>)}
+ * <td></td><td></td><td>X</td><td></td>
+ * </tr>
+ * <tr><td>{@link #getAnnotations Annotation[] getAnnotations()}
+ * <td></td><td></td><td>X</td><td></td>
+ * </tr>
+ * <tr><td>{@link #getAnnotationsByType(Class) T[] getAnnotationsByType(Class<T>}
+ * <td></td><td></td><td></td><td>X</td>
+ * </tr>
+ * <tr><td>{@link #getDeclaredAnnotation(Class) T getDeclaredAnnotation(Class<T>)}
+ * <td>X</td><td></td><td></td><td></td>
+ * </tr>
+ * <tr><td>{@link #getDeclaredAnnotationsByType(Class) T[] getDeclaredAnnotationsByType(Class<T>)}
+ * <td>X</td><td>X</td><td></td><td></td>
+ * </tr>
+ * <tr><td>{@link #getDeclaredAnnotations Annotation[] getDeclaredAnnotations()}
+ * <td>X</td><td></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>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>Attempting to read annotations of a repeatable annotation type T
- * that are contained in an annotation whose type is not, in fact, the
- * containing annotation type of T, will result in an {@link
- * AnnotationFormatError}.
+ * <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}.
@@ -104,11 +157,11 @@
* @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 <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}
*
@@ -126,11 +179,11 @@
return getAnnotation(annotationClass) != null;
}
/**
* Returns this element's annotation for the specified type if
- * such an annotation is present, else null.
+ * 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
@@ -144,10 +197,24 @@
* 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.
@@ -157,69 +224,58 @@
*
* @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
- * present on this element, else an array of length zero
+ * associated with this element, else an array of length zero
* @throws NullPointerException if the given annotation class is null
* @since 1.8
*/
<T extends Annotation> T[] getAnnotationsByType(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 this element's annotation for the specified type if
- * such an annotation is present, else null.
+ * 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.)
*
- * @param <T> the type of the annotation to query for and return if present
+ * @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
- * present on this element, else null
+ * directly present on this element, else null
* @throws NullPointerException if the given annotation class is null
* @since 1.8
*/
<T extends Annotation> T getDeclaredAnnotation(Class<T> 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.
+ * 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.
+ * 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.
*
* @param <T> the type of the annotation to query for and return
- * if directly present
+ * 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
- * present on this element, else an array of length zero
+ * 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
*/
<T extends Annotation> T[] getDeclaredAnnotationsByType(Class<T> annotationClass);