/* * Copyright (c) 2005, 2024, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ /** * Interfaces used to model elements of the Java programming language. * * The term "element" in this package is used to refer to program * elements, the declared entities that make up a program. Elements * include classes, interfaces, methods, constructors, and fields. * The interfaces in this package do not model the structure of a * program inside a method body; for example, there is no * representation of a {@code for} loop or {@code try}-{@code finally} * block. Concretely, there is no model of any abstract syntax tree * (AST) structure of a Java program. However, the interfaces can * model some structures only appearing inside method bodies, such as * {@linkplain ElementKind#LOCAL_VARIABLE local variables}, * {@linkplain NestingKind#ANONYMOUS anonymous classes}, and * {@linkplain ElementKind#EXCEPTION_PARAMETER exception parameters}. * Therefore, these interfaces can be used by an AST API to model the * declarations found in the method bodies of Java compilation units * (JLS {@jls 7.3}). * *

When used in the context of annotation * processing, an accurate model of the element being represented must * be returned. As this is a language model, the source code provides * the fiducial (reference) representation of the construct in * question rather than a representation in an executable output like * a class file. Executable output may serve as the basis for * creating a modeling element. However, the process of translating * source code to executable output may not permit recovering some * aspects of the source code representation. For example, * annotations with {@linkplain * java.lang.annotation.RetentionPolicy#SOURCE source} {@linkplain * java.lang.annotation.Retention retention} cannot be recovered from * class files and class files might not be able to provide source * position information. * * Names of {@linkplain * javax.lang.model.element.ExecutableElement#getParameters() * parameters} may not be recoverable from class files. * * The {@linkplain javax.lang.model.element.Modifier modifiers} on an * element created from a class file may differ in some cases from an * element for the same declaration created from a source file * including: * *

* * Some elements which are {@linkplain * javax.lang.model.util.Elements.Origin#MANDATED mandated} may not be * marked as such when created from class files. * * Additionally, {@linkplain * javax.lang.model.util.Elements.Origin#SYNTHETIC synthetic} * constructs in a class file, such as accessor methods used in * implementing nested classes and {@linkplain * javax.lang.model.util.Elements#isBridge(ExecutableElement) * bridge methods} used in implementing covariant returns, are * translation artifacts strictly outside of this model. However, when * operating on class files, it is helpful to be able to operate on such * elements, screening them out when appropriate. * *

During annotation processing, operating on incomplete or * erroneous programs is necessary; however, there are fewer * guarantees about the nature of the resulting model. If the source * code is not syntactically well-formed or has some other * irrecoverable error that could not be removed by the generation of * new classes or interfaces, a model may or may not be provided as a * quality of implementation issue. If a program for a class or * interface is syntactically valid but erroneous in some other * fashion, any returned model must have no less information than if * all the method bodies in the program were replaced by {@code "throw * new RuntimeException();"}. If a program refers to a missing class * or interface Xyz, the returned model must contain no less * information than if the declaration of class or interface Xyz were * assumed to be {@code "class Xyz {}"}, {@code "interface Xyz {}"}, * {@code "enum Xyz {}"}, {@code "@interface Xyz {}"}, or {@code * "record Xyz {}"}. If a program refers to a missing class or * interface {@code Xyz}, the returned model must contain * no less information than if the declaration of Xyz were assumed to * be {@code "class Xyz {}"} or {@code "interface Xyz {}"} * *

Unless otherwise specified in a particular implementation, the * collections returned by methods in this package should be expected * to be unmodifiable by the caller and unsafe for concurrent access. * *

Unless otherwise specified, methods in this package will throw * a {@code NullPointerException} if given a {@code null} argument. * * @see javax.lang.model.util.Elements * @see javax.lang.model##elementsAndTypes Elements and Types * @see * JSR 269: Pluggable Annotation Processing API * @jls 6.1 Declarations * @jls 7.4 Package Declarations * @jls 7.7 Module Declarations * @jls 8.1 Class Declarations * @jls 8.3 Field Declarations * @jls 8.4 Method Declarations * @jls 8.5 Member Class and Interface Declarations * @jls 8.8 Constructor Declarations * @jls 9.1 Interface Declarations * @since 1.6 */ package javax.lang.model.element;