1 | /* |
2 | * Copyright 2005-2006 Sun Microsystems, Inc. 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. Sun designates this |
8 | * particular file as subject to the "Classpath" exception as provided |
9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
23 | * have any questions. |
24 | */ |
25 | |
26 | package javax.lang.model.util; |
27 | |
28 | import javax.lang.model.type.*; |
29 | |
30 | /** |
31 | * A skeletal visitor of types with default behavior appropriate for |
32 | * the version 6 language level. |
33 | * |
34 | * <p> <b>WARNING:</b> The {@code TypeVisitor} interface implemented |
35 | * by this class may have methods added to it in the future to |
36 | * accommodate new, currently unknown, language structures added to |
37 | * future versions of the Java™ programming language. |
38 | * Therefore, methods whose names begin with {@code "visit"} may be |
39 | * added to this class in the future; to avoid incompatibilities, |
40 | * classes which extend this class should not declare any instance |
41 | * methods with names beginning with {@code "visit"}. |
42 | * |
43 | * <p>When such a new visit method is added, the default |
44 | * implementation in this class will be to call the {@link |
45 | * #visitUnknown visitUnknown} method. A new abstract type visitor |
46 | * class will also be introduced to correspond to the new language |
47 | * level; this visitor will have different default behavior for the |
48 | * visit method in question. When the new visitor is introduced, all |
49 | * or portions of this visitor may be deprecated. |
50 | * |
51 | * @param <R> the return type of this visitor's methods. Use {@link |
52 | * Void} for visitors that do not need to return results. |
53 | * @param <P> the type of the additional parameter to this visitor's |
54 | * methods. Use {@code Void} for visitors that do not need an |
55 | * additional parameter. |
56 | * |
57 | * @author Joseph D. Darcy |
58 | * @author Scott Seligman |
59 | * @author Peter von der Ahé |
60 | * @since 1.6 |
61 | */ |
62 | public abstract class AbstractTypeVisitor6<R, P> implements TypeVisitor<R, P> { |
63 | /** |
64 | * Constructor for concrete subclasses to call. |
65 | */ |
66 | protected AbstractTypeVisitor6() {} |
67 | |
68 | /** |
69 | * Visits any type mirror as if by passing itself to that type |
70 | * mirror's {@link TypeMirror#accept accept} method. The |
71 | * invocation {@code v.visit(t, p)} is equivalent to {@code |
72 | * t.accept(v, p)}. |
73 | * |
74 | * @param t the type to visit |
75 | * @param p a visitor-specified parameter |
76 | * @return a visitor-specified result |
77 | */ |
78 | public final R visit(TypeMirror t, P p) { |
79 | return t.accept(this, p); |
80 | } |
81 | |
82 | /** |
83 | * Visits any type mirror as if by passing itself to that type |
84 | * mirror's {@link TypeMirror#accept accept} method and passing |
85 | * {@code null} for the additional parameter. The invocation |
86 | * {@code v.visit(t)} is equivalent to {@code t.accept(v, null)}. |
87 | * |
88 | * @param t the type to visit |
89 | * @return a visitor-specified result |
90 | */ |
91 | public final R visit(TypeMirror t) { |
92 | return t.accept(this, null); |
93 | } |
94 | |
95 | /** |
96 | * {@inheritDoc} |
97 | * |
98 | * <p> The default implementation of this method in {@code |
99 | * AbstractTypeVisitor6} will always throw {@code |
100 | * UnknownTypeException}. This behavior is not required of a |
101 | * subclass. |
102 | * |
103 | * @param t the type to visit |
104 | * @return a visitor-specified result |
105 | * @throws UnknownTypeException |
106 | * a visitor implementation may optionally throw this exception |
107 | */ |
108 | public R visitUnknown(TypeMirror t, P p) { |
109 | throw new UnknownTypeException(t, p); |
110 | } |
111 | } |