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 }