TypeVariable.java revision 2571:10fc81ac75b4 
1/*
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8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
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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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24 */
25
26package javax.lang.model.type;
27
28
29import javax.lang.model.element.Element;
30import javax.lang.model.element.TypeParameterElement;
31import javax.lang.model.util.Types;
32
33
34/**
35 * Represents a type variable.
36 * A type variable may be explicitly declared by a
37 * {@linkplain TypeParameterElement type parameter} of a
38 * type, method, or constructor.
39 * A type variable may also be declared implicitly, as by
40 * the capture conversion of a wildcard type argument
41 * (see chapter 5 of
42 * <cite>The Java&trade; Language Specification</cite>).
43 *
44 * @author Joseph D. Darcy
45 * @author Scott Seligman
46 * @author Peter von der Ah&eacute;
47 * @see TypeParameterElement
48 * @since 1.6
49 */
50public interface TypeVariable extends ReferenceType {
51
52    /**
53     * Returns the element corresponding to this type variable.
54     *
55     * @return the element corresponding to this type variable
56     */
57    Element asElement();
58
59    /**
60     * Returns the upper bound of this type variable.
61     *
62     * <p> If this type variable was declared with no explicit
63     * upper bounds, the result is {@code java.lang.Object}.
64     * If it was declared with multiple upper bounds,
65     * the result is an {@linkplain IntersectionType intersection type};
66     * individual bounds can be found by examining the result's
67     * {@linkplain IntersectionType#getBounds() bounds}.
68     *
69     * @return the upper bound of this type variable
70     */
71    TypeMirror getUpperBound();
72
73    /**
74     * Returns the lower bound of this type variable.  While a type
75     * parameter cannot include an explicit lower bound declaration,
76     * capture conversion can produce a type variable with a
77     * non-trivial lower bound.  Type variables otherwise have a
78     * lower bound of {@link NullType}.
79     *
80     * @return the lower bound of this type variable
81     */
82    TypeMirror getLowerBound();
83}
84