1 /*
2 * Copyright (c) 2010, 2014, 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 import javax.lang.model.type.*;
29 import javax.annotation.processing.SupportedSourceVersion;
30 import javax.lang.model.SourceVersion;
31 import static javax.lang.model.SourceVersion.*;
32
33 /**
34 * A simple visitor of types with default behavior appropriate for the
35 * {@link SourceVersion#RELEASE_7 RELEASE_7} source version.
36 *
37 * Visit methods corresponding to {@code RELEASE_7} and earlier
38 * language constructs call {@link #defaultAction defaultAction},
39 * passing their arguments to {@code defaultAction}'s corresponding
40 * parameters.
41 *
42 * <p> Methods in this class may be overridden subject to their
43 * general contract. Note that annotating methods in concrete
44 * subclasses with {@link java.lang.Override @Override} will help
45 * ensure that methods are overridden as intended.
46 *
47 * <p> <b>WARNING:</b> The {@code TypeVisitor} interface implemented
48 * by this class may have methods added to it in the future to
49 * accommodate new, currently unknown, language structures added to
50 * future versions of the Java™ programming language.
51 * Therefore, methods whose names begin with {@code "visit"} may be
52 * added to this class in the future; to avoid incompatibilities,
53 * classes which extend this class should not declare any instance
54 * methods with names beginning with {@code "visit"}.
55 *
56 * <p>When such a new visit method is added, the default
57 * implementation in this class will be to call the {@link
58 * #visitUnknown visitUnknown} method. A new simple type visitor
59 * class will also be introduced to correspond to the new language
60 * level; this visitor will have different default behavior for the
61 * visit method in question. When the new visitor is introduced, all
62 * or portions of this visitor may be deprecated.
63 *
64 * <p>Note that adding a default implementation of a new visit method
65 * in a visitor class will occur instead of adding a <em>default
66 * method</em> directly in the visitor interface since a Java SE 8
67 * language feature cannot be used to this version of the API since
68 * this version is required to be runnable on Java SE 7
69 * implementations. Future versions of the API that are only required
70 * to run on Java SE 8 and later may take advantage of default methods
71 * in this situation.
72 *
73 * @param <R> the return type of this visitor's methods. Use {@link
74 * Void} for visitors that do not need to return results.
75 * @param <P> the type of the additional parameter to this visitor's
76 * methods. Use {@code Void} for visitors that do not need an
77 * additional parameter.
78 *
79 * @see SimpleTypeVisitor6
80 * @see SimpleTypeVisitor8
81 * @see SimpleTypeVisitor9
82 * @since 1.7
83 */
84 @SupportedSourceVersion(RELEASE_7)
85 public class SimpleTypeVisitor7<R, P> extends SimpleTypeVisitor6<R, P> {
86 /**
87 * Constructor for concrete subclasses; uses {@code null} for the
88 * default value.
89 */
90 @SuppressWarnings("deprecation") // Superclass constructor deprecated
91 protected SimpleTypeVisitor7(){
92 super(null);
93 }
94
95 /**
96 * Constructor for concrete subclasses; uses the argument for the
97 * default value.
98 *
99 * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
100 */
101 @SuppressWarnings("deprecation") // Superclass constructor deprecated
102 protected SimpleTypeVisitor7(R defaultValue){
103 super(defaultValue);
104 }
105
106 /**
107 * This implementation visits a {@code UnionType} by calling
108 * {@code defaultAction}.
109 *
110 * @param t {@inheritDoc}
111 * @param p {@inheritDoc}
112 * @return the result of {@code defaultAction}
113 */
114 @Override
115 public R visitUnion(UnionType t, P p) {
116 return defaultAction(t, p);
117 }
118 }