SimpleTypeVisitor7.java revision 2571:10fc81ac75b4 
1/*
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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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).
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19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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25
26package javax.lang.model.util;
27
28import javax.lang.model.type.*;
29import javax.annotation.processing.SupportedSourceVersion;
30import javax.lang.model.SourceVersion;
31import 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&trade; 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@SuppressWarnings("deprecation") // Superclass deprecated
85@SupportedSourceVersion(RELEASE_7)
86public class SimpleTypeVisitor7<R, P> extends SimpleTypeVisitor6<R, P> {
87    /**
88     * Constructor for concrete subclasses; uses {@code null} for the
89     * default value.
90     */
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    protected SimpleTypeVisitor7(R defaultValue){
102        super(defaultValue);
103    }
104
105    /**
106     * This implementation visits a {@code UnionType} by calling
107     * {@code defaultAction}.
108     *
109     * @param t  {@inheritDoc}
110     * @param p  {@inheritDoc}
111     * @return the result of {@code defaultAction}
112     */
113    @Override
114    public R visitUnion(UnionType t, P p) {
115        return defaultAction(t, p);
116    }
117}
118