1 /*
2 * Copyright (c) 2005, 2016, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package javax.lang.model.util;
27
28
29 import java.util.List;
30 import java.util.Map;
31
32 import javax.lang.model.element.*;
33
34
35 /**
36 * Utility methods for operating on program elements.
37 *
38 * <p><b>Compatibility Note:</b> Methods may be added to this interface
39 * in future releases of the platform.
40 *
41 * @author Joseph D. Darcy
42 * @author Scott Seligman
43 * @author Peter von der Ahé
44 * @see javax.annotation.processing.ProcessingEnvironment#getElementUtils
45 * @since 1.6
46 */
47 public interface Elements {
48
49 /**
50 * Returns a package given its fully qualified name.
51 *
52 * @param name fully qualified package name, or an empty string for an unnamed package
53 * @return the named package, or {@code null} if it cannot be found
54 */
55 PackageElement getPackageElement(CharSequence name);
56
57 /**
58 * Returns a package given its fully qualified name, as seen from the given module.
59 *
60 * @param name fully qualified package name, or an empty string for an unnamed package
61 * @param module module relative to which the lookup should happen
62 * @return the named package, or {@code null} if it cannot be found
63 * @since 9
64 */
65 PackageElement getPackageElement(ModuleElement module, CharSequence name);
66
67 /**
68 * Returns a type element given its canonical name.
69 *
70 * @param name the canonical name
71 * @return the named type element, or {@code null} if it cannot be found
72 */
73 TypeElement getTypeElement(CharSequence name);
74
75 /**
76 * Returns a type element given its canonical name, as seen from the given module.
77 *
78 * @param name the canonical name
79 * @param module module relative to which the lookup should happen
80 * @return the named type element, or {@code null} if it cannot be found
81 * @since 9
82 */
83 TypeElement getTypeElement(ModuleElement module, CharSequence name);
84
85 /**
86 * Returns a module element given its fully qualified name.
87 *
88 * @param name the name
89 * @return the named module element, or {@code null} if it cannot be found
90 * @since 9
91 */
92 ModuleElement getModuleElement(CharSequence name);
93
94 /**
95 * Returns the values of an annotation's elements, including defaults.
96 *
97 * @see AnnotationMirror#getElementValues()
98 * @param a annotation to examine
99 * @return the values of the annotation's elements, including defaults
100 */
101 Map<? extends ExecutableElement, ? extends AnnotationValue>
102 getElementValuesWithDefaults(AnnotationMirror a);
103
104 /**
105 * Returns the text of the documentation ("Javadoc")
106 * comment of an element.
107 *
108 * <p> A documentation comment of an element is a comment that
109 * begins with "{@code /**}" , ends with a separate
110 * "<code>*/</code>", and immediately precedes the element,
111 * ignoring white space. Therefore, a documentation comment
112 * contains at least three"{@code *}" characters. The text
113 * returned for the documentation comment is a processed form of
114 * the comment as it appears in source code. The leading "{@code
115 * /**}" and trailing "<code>*/</code>" are removed. For lines
116 * of the comment starting after the initial "{@code /**}",
117 * leading white space characters are discarded as are any
118 * consecutive "{@code *}" characters appearing after the white
119 * space or starting the line. The processed lines are then
120 * concatenated together (including line terminators) and
121 * returned.
122 *
123 * @param e the element being examined
124 * @return the documentation comment of the element, or {@code null}
125 * if there is none
126 * @jls 3.6 White Space
127 */
128 String getDocComment(Element e);
129
130 /**
131 * Returns {@code true} if the element is deprecated, {@code false} otherwise.
132 *
133 * @param e the element being examined
134 * @return {@code true} if the element is deprecated, {@code false} otherwise
135 */
136 boolean isDeprecated(Element e);
137
138 /**
139 * Returns the <i>binary name</i> of a type element.
140 *
141 * @param type the type element being examined
142 * @return the binary name
143 *
144 * @see TypeElement#getQualifiedName
145 * @jls 13.1 The Form of a Binary
146 */
147 Name getBinaryName(TypeElement type);
148
149
150 /**
151 * Returns the package of an element. The package of a package is
152 * itself.
153 *
154 * @param type the element being examined
155 * @return the package of an element
156 */
157 PackageElement getPackageOf(Element type);
158
159 /**
160 * Returns the module of an element. The module of a module is
161 * itself.
162 *
163 * @param type the element being examined
164 * @return the module of an element
165 * @since 9
166 */
167 ModuleElement getModuleOf(Element type);
168
169 /**
170 * Returns all members of a type element, whether inherited or
171 * declared directly. For a class the result also includes its
172 * constructors, but not local or anonymous classes.
173 *
174 * <p>Note that elements of certain kinds can be isolated using
175 * methods in {@link ElementFilter}.
176 *
177 * @param type the type being examined
178 * @return all members of the type
179 * @see Element#getEnclosedElements
180 */
181 List<? extends Element> getAllMembers(TypeElement type);
182
183 /**
184 * Returns all annotations <i>present</i> on an element, whether
185 * directly present or present via inheritance.
186 *
187 * @param e the element being examined
188 * @return all annotations of the element
189 * @see Element#getAnnotationMirrors
190 * @see javax.lang.model.AnnotatedConstruct
191 */
192 List<? extends AnnotationMirror> getAllAnnotationMirrors(Element e);
193
194 /**
195 * Tests whether one type, method, or field hides another.
196 *
197 * @param hider the first element
198 * @param hidden the second element
199 * @return {@code true} if and only if the first element hides
200 * the second
201 */
202 boolean hides(Element hider, Element hidden);
203
204 /**
205 * Tests whether one method, as a member of a given type,
206 * overrides another method.
207 * When a non-abstract method overrides an abstract one, the
208 * former is also said to <i>implement</i> the latter.
209 *
210 * <p> In the simplest and most typical usage, the value of the
211 * {@code type} parameter will simply be the class or interface
212 * directly enclosing {@code overrider} (the possibly-overriding
213 * method). For example, suppose {@code m1} represents the method
214 * {@code String.hashCode} and {@code m2} represents {@code
215 * Object.hashCode}. We can then ask whether {@code m1} overrides
216 * {@code m2} within the class {@code String} (it does):
217 *
218 * <blockquote>
219 * {@code assert elements.overrides(m1, m2,
220 * elements.getTypeElement("java.lang.String")); }
221 * </blockquote>
222 *
223 * A more interesting case can be illustrated by the following example
224 * in which a method in type {@code A} does not override a
225 * like-named method in type {@code B}:
226 *
227 * <blockquote>
228 * {@code class A { public void m() {} } }<br>
229 * {@code interface B { void m(); } }<br>
230 * ...<br>
231 * {@code m1 = ...; // A.m }<br>
232 * {@code m2 = ...; // B.m }<br>
233 * {@code assert ! elements.overrides(m1, m2,
234 * elements.getTypeElement("A")); }
235 * </blockquote>
236 *
237 * When viewed as a member of a third type {@code C}, however,
238 * the method in {@code A} does override the one in {@code B}:
239 *
240 * <blockquote>
241 * {@code class C extends A implements B {} }<br>
242 * ...<br>
243 * {@code assert elements.overrides(m1, m2,
244 * elements.getTypeElement("C")); }
245 * </blockquote>
246 *
247 * @param overrider the first method, possible overrider
248 * @param overridden the second method, possibly being overridden
249 * @param type the type of which the first method is a member
250 * @return {@code true} if and only if the first method overrides
251 * the second
252 * @jls 8.4.8 Inheritance, Overriding, and Hiding
253 * @jls 9.4.1 Inheritance and Overriding
254 */
255 boolean overrides(ExecutableElement overrider, ExecutableElement overridden,
256 TypeElement type);
257
258 /**
259 * Returns the text of a <i>constant expression</i> representing a
260 * primitive value or a string.
261 * The text returned is in a form suitable for representing the value
262 * in source code.
263 *
264 * @param value a primitive value or string
265 * @return the text of a constant expression
266 * @throws IllegalArgumentException if the argument is not a primitive
267 * value or string
268 *
269 * @see VariableElement#getConstantValue()
270 */
271 String getConstantExpression(Object value);
272
273 /**
274 * Prints a representation of the elements to the given writer in
275 * the specified order. The main purpose of this method is for
276 * diagnostics. The exact format of the output is <em>not</em>
277 * specified and is subject to change.
278 *
279 * @param w the writer to print the output to
280 * @param elements the elements to print
281 */
282 void printElements(java.io.Writer w, Element... elements);
283
284 /**
285 * Return a name with the same sequence of characters as the
286 * argument.
287 *
288 * @param cs the character sequence to return as a name
289 * @return a name with the same sequence of characters as the argument
290 */
291 Name getName(CharSequence cs);
292
293 /**
294 * Returns {@code true} if the type element is a functional interface, {@code false} otherwise.
295 *
296 * @param type the type element being examined
297 * @return {@code true} if the element is a functional interface, {@code false} otherwise
298 * @jls 9.8 Functional Interfaces
299 * @since 1.8
300 */
301 boolean isFunctionalInterface(TypeElement type);
302 }