1/*
2 * Copyright (c) 2005, 2012, 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
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24 */
25
26package javax.annotation.processing;
27
28import java.util.Map;
29import java.util.Locale;
30import javax.lang.model.SourceVersion;
31import javax.lang.model.util.Elements;
32import javax.lang.model.util.Types;
33
34/**
35 * An annotation processing tool framework will {@linkplain
36 * Processor#init provide an annotation processor with an object
37 * implementing this interface} so the processor can use facilities
38 * provided by the framework to write new files, report error
39 * messages, and find other utilities.
40 *
41 * <p>Third parties may wish to provide value-add wrappers around the
42 * facility objects from this interface, for example a {@code Filer}
43 * extension that allows multiple processors to coordinate writing out
44 * a single source file.  To enable this, for processors running in a
45 * context where their side effects via the API could be visible to
46 * each other, the tool infrastructure must provide corresponding
47 * facility objects that are {@code .equals}, {@code Filer}s that are
48 * {@code .equals}, and so on.  In addition, the tool invocation must
49 * be able to be configured such that from the perspective of the
50 * running annotation processors, at least the chosen subset of helper
51 * classes are viewed as being loaded by the same class loader.
52 * (Since the facility objects manage shared state, the implementation
53 * of a wrapper class must know whether or not the same base facility
54 * object has been wrapped before.)
55 *
56 * @author Joseph D. Darcy
57 * @author Scott Seligman
58 * @author Peter von der Ah&eacute;
59 * @since 1.6
60 */
61public interface ProcessingEnvironment {
62    /**
63     * Returns the processor-specific options passed to the annotation
64     * processing tool.  Options are returned in the form of a map from
65     * option name to option value.  For an option with no value, the
66     * corresponding value in the map is {@code null}.
67     *
68     * <p>See documentation of the particular tool infrastructure
69     * being used for details on how to pass in processor-specific
70     * options.  For example, a command-line implementation may
71     * distinguish processor-specific options by prefixing them with a
72     * known string like {@code "-A"}; other tool implementations may
73     * follow different conventions or provide alternative mechanisms.
74     * A given implementation may also provide implementation-specific
75     * ways of finding options passed to the tool in addition to the
76     * processor-specific options.
77     *
78     * @return the processor-specific options passed to the tool
79     */
80    Map<String,String> getOptions();
81
82    /**
83     * Returns the messager used to report errors, warnings, and other
84     * notices.
85     *
86     * @return the messager
87     */
88    Messager getMessager();
89
90    /**
91     * Returns the filer used to create new source, class, or auxiliary
92     * files.
93     *
94     * @return the filer
95     */
96    Filer getFiler();
97
98    /**
99     * Returns an implementation of some utility methods for
100     * operating on elements
101     *
102     * @return element utilities
103     */
104    Elements getElementUtils();
105
106    /**
107     * Returns an implementation of some utility methods for
108     * operating on types.
109     *
110     * @return type utilities
111     */
112    Types getTypeUtils();
113
114    /**
115     * Returns the source version that any generated {@linkplain
116     * Filer#createSourceFile source} and {@linkplain
117     * Filer#createClassFile class} files should conform to.
118     *
119     * @return the source version to which generated source and class
120     *         files should conform to
121     * @see Processor#getSupportedSourceVersion
122     */
123    SourceVersion getSourceVersion();
124
125    /**
126     * Returns the current locale or {@code null} if no locale is in
127     * effect.  The locale can be be used to provide localized
128     * {@linkplain Messager messages}.
129     *
130     * @return the current locale or {@code null} if no locale is in
131     * effect
132     */
133    Locale getLocale();
134}
135