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 /** 27 * Interfaces used to model elements of the Java programming language. 28 * 29 * The term "element" in this package is used to refer to program 30 * elements, the declared entities that make up a program. Elements 31 * include classes, interfaces, methods, constructors, and fields. 32 * The interfaces in this package do not model the structure of a 33 * program inside a method body; for example there is no 34 * representation of a {@code for} loop or {@code try}-{@code finally} 35 * block. However, the interfaces can model some structures only 36 * appearing inside method bodies, such as local variables and 37 * anonymous classes. 38 * 39 * <p>When used in the context of annotation processing, an accurate 40 * model of the element being represented must be returned. As this 41 * is a language model, the source code provides the fiducial 42 * (reference) representation of the construct in question rather than 43 * a representation in an executable output like a class file. 44 * Executable output may serve as the basis for creating a modeling 45 * element. However, the process of translating source code to 46 * executable output may not permit recovering some aspects of the 47 * source code representation. For example, annotations with 48 * {@linkplain java.lang.annotation.RetentionPolicy#SOURCE source} 49 * {@linkplain java.lang.annotation.Retention retention} cannot be 50 * recovered from class files and class files might not be able to 51 * provide source position information. 52 * 53 * Names of parameters may not be recoverable from class files. 54 * 55 * The {@linkplain javax.lang.model.element.Modifier modifiers} on an 56 * element created from a class file may differ in some cases from an 57 * element for the same declaration created from a source file 58 * including: 59 * 60 * <ul> 61 * <li> {@code strictfp} on a class or interface 62 * <li> {@code final} on a parameter 63 * <li> {@code protected}, {@code private}, and {@code static} on classes and interfaces 64 * </ul> 65 * 66 * Some elements which are {@linkplain 67 * javax.lang.model.util.Elements.Origin#MANDATED mandated} may not be 68 * marked as such when created from class files. 69 * 70 * Additionally, {@linkplain 71 * javax.lang.model.util.Elements.Origin#SYNTHETIC synthetic} 72 * constructs in a class file, such as accessor methods used in 73 * implementing nested classes and {@linkplain 74 * javax.lang.model.util.Elements.Origin#isBridge(ExecutableElement) 75 * bridge methods} used in implementing covariant returns, are 76 * translation artifacts strictly outside of this model. However, when 77 * operating on class files, it is helpful be able to operate on such 78 * elements, screening them out when appropriate. 79 * 80 * <p>During annotation processing, operating on incomplete or 81 * erroneous programs is necessary; however, there are fewer 82 * guarantees about the nature of the resulting model. If the source 83 * code is not syntactically well-formed or has some other 84 * irrecoverable error that could not be removed by the generation of 85 * new types, a model may or may not be provided as a quality of 86 * implementation issue. 87 * If a program is syntactically valid but erroneous in some other 88 * fashion, any returned model must have no less information than if 89 * all the method bodies in the program were replaced by {@code "throw 90 * new RuntimeException();"}. If a program refers to a missing type XYZ, 91 * the returned model must contain no less information than if the 92 * declaration of type XYZ were assumed to be {@code "class XYZ {}"}, 93 * {@code "interface XYZ {}"}, {@code "enum XYZ {}"}, or {@code 94 * "@interface XYZ {}"}. If a program refers to a missing type {@code 95 * XYZ<K1, ... ,Kn>}, the returned model must contain no less 96 * information than if the declaration of XYZ were assumed to be 97 * {@code "class XYZ<T1, ... ,Tn> {}"} or {@code "interface XYZ<T1, 98 * ... ,Tn> {}"} 99 * 100 * <p> Unless otherwise specified in a particular implementation, the 101 * collections returned by methods in this package should be expected 102 * to be unmodifiable by the caller and unsafe for concurrent access. 103 * 104 * <p> Unless otherwise specified, methods in this package will throw 105 * a {@code NullPointerException} if given a {@code null} argument. 106 * 107 * @author Joseph D. Darcy 108 * @author Scott Seligman 109 * @author Peter von der Ahé 110 * @since 1.6 111 */ 112 package javax.lang.model.element;