01 /*
02 * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved.
03 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
04 *
05 * This code is free software; you can redistribute it and/or modify it
06 * under the terms of the GNU General Public License version 2 only, as
07 * published by the Free Software Foundation. Sun designates this
08 * particular file as subject to the "Classpath" exception as provided
09 * 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.type;
27
28 import javax.lang.model.element.Element;
29 import javax.lang.model.element.TypeParameterElement;
30 import javax.lang.model.util.Types;
31
32 /**
33 * Represents a type variable.
34 * A type variable may be explicitly declared by a
35 * {@linkplain TypeParameterElement type parameter} of a
36 * type, method, or constructor.
37 * A type variable may also be declared implicitly, as by
38 * the capture conversion of a wildcard type argument
39 * (see chapter 5 of <i>The Java Language Specification, Third
40 * Edition</i>).
41 *
42 * @author Joseph D. Darcy
43 * @author Scott Seligman
44 * @author Peter von der Ahé
45 * @version 1.10 07/05/05
46 * @see TypeParameterElement
47 * @since 1.6
48 */
49 public interface TypeVariable extends ReferenceType {
50
51 /**
52 * Returns the element corresponding to this type variable.
53 *
54 * @return the element corresponding to this type variable
55 */
56 Element asElement();
57
58 /**
59 * Returns the upper bound of this type variable.
60 *
61 * <p> If this type variable was declared with no explicit
62 * upper bounds, the result is {@code java.lang.Object}.
63 * If it was declared with multiple upper bounds,
64 * the result is an intersection type (modeled as a
65 * {@link DeclaredType}).
66 * Individual bounds can be found by examining the result's
67 * {@linkplain Types#directSupertypes(TypeMirror) supertypes}.
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 }
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