22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.lang.model;
27
28 import java.lang.annotation.*;
29 import java.util.List;
30 import javax.lang.model.element.*;
31 import javax.lang.model.type.*;
32
33 /**
34 * Represents a construct that can be annotated.
35 *
36 * A construct is either an {@linkplain
37 * javax.lang.model.element.Element element} or a {@linkplain
38 * javax.lang.model.type.TypeMirror type}. Annotations on an element
39 * are on a <em>declaration</em>, whereas annotations on a type are on
40 * a specific <em>use</em> of a type name.
41 *
42 * The terms <em>directly present</em> and <em>present</em> are used
43 * throughout this interface to describe precisely which annotations
44 * are returned by methods:
45 *
46 * <p>An annotation <i>A</i> is <em>directly present</em> on a
47 * construct <i>E</i> if <i>E</i> is annotated, and:
48 *
49 * <ul>
50 *
51 * <li> for an invocation of {@code getAnnotation(Class<T>)} or
52 * {@code getAnnotationMirrors()}, <i>E</i>'s annotations contain <i>A</i>.
53 *
54 * <li> for an invocation of {@code getAnnotationsByType(Class<T>)},
55 * <i>E</i>'s annotations either contain <i>A</i> or, if the type of
56 * <i>A</i> is repeatable, contain exactly one annotation whose value
57 * element contains <i>A</i> and whose type is the containing
58 * annotation type of <i>A</i>'s type.
59 *
60 * </ul>
61 *
62 * <p>An annotation A is <em>present</em> on a construct E if either:
63 *
64 * <ul>
65 * <li> <i>A</i> is <em>directly present</em> on <i>E</i>; or
66 *
67 * <li> <i>A</i> is not <em>directly present</em> on <i>E</i>, and
68 * <i>E</i> is an element representing a class, and <i>A</i>'s type
69 * is inheritable, and <i>A</i> is <em>present</em> on the element
70 * representing the superclass of <i>E</i>.
71 *
72 * </ul>
73 *
74 * @since 1.8
75 * @jls 9.6 Annotation Types
76 * @jls 9.6.3.3 @Inherited
77 */
78 public interface AnnotatedConstruct {
79 /**
80 * Returns the annotations that are <em>directly present</em> on
81 * this construct.
82 *
83 * @return the annotations <em>directly present</em> on this
84 * construct; an empty list if there are none
85 */
86 List<? extends AnnotationMirror> getAnnotationMirrors();
87
88 /**
89 * Returns this construct's annotation of the
90 * specified type if such an annotation is <em>present</em>, else {@code
91 * null}.
92 *
93 * <p> The annotation returned by this method could contain an element
94 * whose value is of type {@code Class}.
95 * This value cannot be returned directly: information necessary to
96 * locate and load a class (such as the class loader to use) is
97 * not available, and the class might not be loadable at all.
98 * Attempting to read a {@code Class} object by invoking the relevant
99 * method on the returned annotation
100 * will result in a {@link MirroredTypeException},
101 * from which the corresponding {@link TypeMirror} may be extracted.
102 * Similarly, attempting to read a {@code Class[]}-valued element
103 * will result in a {@link MirroredTypesException}.
104 *
105 * <blockquote>
106 * <i>Note:</i> This method is unlike others in this and related
107 * interfaces. It operates on runtime reflective information —
108 * representations of annotation types currently loaded into the
109 * VM — rather than on the representations defined by and used
110 * throughout these interfaces. Consequently, calling methods on
111 * the returned annotation object can throw many of the exceptions
112 * that can be thrown when calling methods on an annotation object
113 * returned by core reflection. This method is intended for
114 * callers that are written to operate on a known, fixed set of
115 * annotation types.
116 * </blockquote>
117 *
118 * @param <A> the annotation type
119 * @param annotationType the {@code Class} object corresponding to
120 * the annotation type
121 * @return this element's or type use's annotation for the
122 * specified annotation type if present on this element, else
123 * {@code null}
124 *
125 * @see #getAnnotationMirrors()
126 * @see java.lang.reflect.AnnotatedElement#getAnnotation
127 * @see EnumConstantNotPresentException
128 * @see AnnotationTypeMismatchException
129 * @see IncompleteAnnotationException
130 * @see MirroredTypeException
131 * @see MirroredTypesException
132 * @jls 9.6.1 Annotation Type Elements
133 */
134 <A extends Annotation> A getAnnotation(Class<A> annotationType);
135
136 /**
137 * Returns annotations that are <em>present</em> on this construct.
138 *
139 * If there are no annotations <em>present</em> on this construct,
140 * the return value is an array of length 0.
141 *
142 * The difference between this method and {@link #getAnnotation(Class)}
143 * is that this method detects if its argument is a <em>repeatable
144 * annotation type</em>, and if so, attempts to find one or more
145 * annotations of that type by "looking through" a container annotation.
146 *
147 * <p> The annotations returned by this method could contain an element
148 * whose value is of type {@code Class}.
149 * This value cannot be returned directly: information necessary to
150 * locate and load a class (such as the class loader to use) is
151 * not available, and the class might not be loadable at all.
152 * Attempting to read a {@code Class} object by invoking the relevant
153 * method on the returned annotation
154 * will result in a {@link MirroredTypeException},
155 * from which the corresponding {@link TypeMirror} may be extracted.
156 * Similarly, attempting to read a {@code Class[]}-valued element
157 * will result in a {@link MirroredTypesException}.
158 *
159 * <blockquote>
160 * <i>Note:</i> This method is unlike others in this and related
161 * interfaces. It operates on runtime reflective information —
162 * representations of annotation types currently loaded into the
163 * VM — rather than on the representations defined by and used
164 * throughout these interfaces. Consequently, calling methods on
165 * the returned annotation object can throw many of the exceptions
166 * that can be thrown when calling methods on an annotation object
167 * returned by core reflection. This method is intended for
168 * callers that are written to operate on a known, fixed set of
169 * annotation types.
170 * </blockquote>
171 *
172 * @param <A> the annotation type
173 * @param annotationType the {@code Class} object corresponding to
174 * the annotation type
175 * @return this element's annotations for the specified annotation
176 * type if present on this element, else an empty array
177 *
178 * @see #getAnnotationMirrors()
179 * @see #getAnnotation(java.lang.Class)
180 * @see java.lang.reflect.AnnotatedElement#getAnnotationsByType
181 * @see EnumConstantNotPresentException
182 * @see AnnotationTypeMismatchException
183 * @see IncompleteAnnotationException
184 * @see MirroredTypeException
185 * @see MirroredTypesException
186 * @jls 9.6 Annotation Types
187 * @jls 9.6.1 Annotation Type Elements
188 */
189 <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationType);
190 }
|
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.lang.model;
27
28 import java.lang.annotation.*;
29 import java.util.List;
30 import javax.lang.model.element.*;
31 import javax.lang.model.type.*;
32
33 /**
34 * Represents a construct that can be annotated.
35 *
36 * A construct is either an {@linkplain
37 * javax.lang.model.element.Element element} or a {@linkplain
38 * javax.lang.model.type.TypeMirror type}. Annotations on an element
39 * are on a <em>declaration</em>, whereas annotations on a type are on
40 * a specific <em>use</em> of a type name.
41 *
42 * The terms <em>directly present</em>, <em>present</em>,
43 * <em>indirectly present</em>, and <em>associated </em> are used
44 * throughout this interface to describe precisely which annotations
45 * are returned by the methods defined herein.
46 *
47 * <p>In the definitions below, an annotation <i>A</i> has an
48 * annotation type <i>AT</i>. If <i>AT</i> is a repeatable annotation
49 * type, the type of the containing annotation is <i>ATC</i>.
50 *
51 * <p>Annotation <i>A</i> is <em>directly present</em> on a construct
52 * <i>C</i> if either:
53 *
54 * <ul>
55 *
56 * <li><i>A</i> is explicitly or implicitly declared as applying to
57 * the source code representation of <i>C</i>.
58 *
59 * <p>Typically, if exactly one annotation of type <i>AT</i> appears in
60 * the source code of representation of <i>C</i>, then <i>A</i> is
61 * explicitly declared as applying to <i>C</i>.
62 *
63 * If there are multiple annotations of type <i>AT</i> present on
64 * <i>C</i>, then if <i>AT</i> is repeatable annotation type, an
65 * annotation of type <i>ATC</i> is implicitly declared on <i>C</i>.
66 *
67 * <li> A representation of <i>A</i> appears in the executable output
68 * for <i>C</i>, such as the {@code RuntimeVisibleAnnotations} or
69 * {@code RuntimeVisibleParameterAnnotations} attributes of a class
70 * file.
71 *
72 * </ul>
73 *
74 * <p>An annotation <i>A</i> is <em>present</em> on a
75 * construct <i>C</i> if either:
76 * <ul>
77 *
78 * <li><i>A</i> is directly present on <i>C</i>.
79 *
80 * <li>No annotation of type <i>AT</i> is directly present on
81 * <i>C</i>, and <i>C</i> is a class and <i>AT</i> is inheritable
82 * and <i>A</i> is present on the superclass of <i>C</i>.
83 *
84 * </ul>
85 *
86 * An annotation <i>A</i> is <em>indirectly present</em> on a construct
87 * <i>C</i> if both:
88 *
89 * <ul>
90 *
91 * <li><i>AT</i> is a repeatable annotation type with a containing
92 * annotation type <i>ATC</i>.
93 *
94 * <li>An annotation of type <i>ATC</i> is directly present on
95 * <i>C</i> and <i>A</i> is an annotation included in the result of
96 * calling the {@code value} method of the directly present annotation
97 * of type <i>ATC</i>.
98 *
99 * </ul>
100 *
101 * An annotation <i>A</i> is <em>associated</em> with a construct
102 * <i>C</i> if either:
103 *
104 * <ul>
105 *
106 * <li> <i>A</i> is directly or indirectly present on <i>C</i>.
107 *
108 * <li> No annotation of type <i>AT</i> is directly or indirectly
109 * present on <i>C</i>, and <i>C</i> is a class, and <i>AT</i> is
110 * inheritable, and <i>A</i> is associated with the superclass of
111 * <i>C</i>.
112 *
113 * </ul>
114 *
115 * @since 1.8
116 * @jls 9.6 Annotation Types
117 * @jls 9.6.3.3 @Inherited
118 */
119 public interface AnnotatedConstruct {
120 /**
121 * Returns the annotations that are <em>directly present</em> on
122 * this construct.
123 *
124 * @return the annotations <em>directly present</em> on this
125 * construct; an empty list if there are none
126 */
127 List<? extends AnnotationMirror> getAnnotationMirrors();
128
129 /**
130 * Returns this construct's annotation of the specified type if
131 * such an annotation is <em>present</em>, else {@code null}.
132 *
133 * <p> The annotation returned by this method could contain an element
134 * whose value is of type {@code Class}.
135 * This value cannot be returned directly: information necessary to
136 * locate and load a class (such as the class loader to use) is
137 * not available, and the class might not be loadable at all.
138 * Attempting to read a {@code Class} object by invoking the relevant
139 * method on the returned annotation
140 * will result in a {@link MirroredTypeException},
141 * from which the corresponding {@link TypeMirror} may be extracted.
142 * Similarly, attempting to read a {@code Class[]}-valued element
143 * will result in a {@link MirroredTypesException}.
144 *
145 * <blockquote>
146 * <i>Note:</i> This method is unlike others in this and related
147 * interfaces. It operates on runtime reflective information —
148 * representations of annotation types currently loaded into the
149 * VM — rather than on the representations defined by and used
150 * throughout these interfaces. Consequently, calling methods on
151 * the returned annotation object can throw many of the exceptions
152 * that can be thrown when calling methods on an annotation object
153 * returned by core reflection. This method is intended for
154 * callers that are written to operate on a known, fixed set of
155 * annotation types.
156 * </blockquote>
157 *
158 * @param <A> the annotation type
159 * @param annotationType the {@code Class} object corresponding to
160 * the annotation type
161 * @return this construct's annotation for the specified
162 * annotation type if present, else {@code null}
163 *
164 * @see #getAnnotationMirrors()
165 * @see java.lang.reflect.AnnotatedElement#getAnnotation
166 * @see EnumConstantNotPresentException
167 * @see AnnotationTypeMismatchException
168 * @see IncompleteAnnotationException
169 * @see MirroredTypeException
170 * @see MirroredTypesException
171 * @jls 9.6.1 Annotation Type Elements
172 */
173 <A extends Annotation> A getAnnotation(Class<A> annotationType);
174
175 /**
176 * Returns annotations that are <em>associated</em> with this construct.
177 *
178 * If there are no annotations associated with this construct, the
179 * return value is an array of length 0.
180 *
181 * The order of annotations which are directly or indirectly
182 * present on a construct <i>C</i> is computed as if indirectly present
183 * annotations on <i>C</i> are directly present on <i>C</i> in place of their
184 * container annotation, in the order in which they appear in the
185 * value element of the container annotation.
186 *
187 * The difference between this method and {@link #getAnnotation(Class)}
188 * is that this method detects if its argument is a <em>repeatable
189 * annotation type</em>, and if so, attempts to find one or more
190 * annotations of that type by "looking through" a container annotation.
191 *
192 * <p> The annotations returned by this method could contain an element
193 * whose value is of type {@code Class}.
194 * This value cannot be returned directly: information necessary to
195 * locate and load a class (such as the class loader to use) is
196 * not available, and the class might not be loadable at all.
197 * Attempting to read a {@code Class} object by invoking the relevant
198 * method on the returned annotation
199 * will result in a {@link MirroredTypeException},
200 * from which the corresponding {@link TypeMirror} may be extracted.
201 * Similarly, attempting to read a {@code Class[]}-valued element
202 * will result in a {@link MirroredTypesException}.
203 *
204 * <blockquote>
205 * <i>Note:</i> This method is unlike others in this and related
206 * interfaces. It operates on runtime reflective information —
207 * representations of annotation types currently loaded into the
208 * VM — rather than on the representations defined by and used
209 * throughout these interfaces. Consequently, calling methods on
210 * the returned annotation object can throw many of the exceptions
211 * that can be thrown when calling methods on an annotation object
212 * returned by core reflection. This method is intended for
213 * callers that are written to operate on a known, fixed set of
214 * annotation types.
215 * </blockquote>
216 *
217 * @param <A> the annotation type
218 * @param annotationType the {@code Class} object corresponding to
219 * the annotation type
220 * @return this construct's annotations for the specified annotation
221 * type if present on this construct, else an empty array
222 *
223 * @see #getAnnotationMirrors()
224 * @see #getAnnotation(java.lang.Class)
225 * @see java.lang.reflect.AnnotatedElement#getAnnotationsByType
226 * @see EnumConstantNotPresentException
227 * @see AnnotationTypeMismatchException
228 * @see IncompleteAnnotationException
229 * @see MirroredTypeException
230 * @see MirroredTypesException
231 * @jls 9.6 Annotation Types
232 * @jls 9.6.1 Annotation Type Elements
233 */
234 <A extends Annotation> A[] getAnnotationsByType(Class<A> annotationType);
235 }
|