package-info.java revision 3825:6b18edbd77b7 
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 Ah&eacute;
110 * @since 1.6
111 */
112package javax.lang.model.element;
113