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 * 61 * @see AbstractTypeVisitor7 62 * @since 1.6 63 */ 64 public abstract class AbstractTypeVisitor6<R, P> implements TypeVisitor<R, P> { 65 /** 66 * Constructor for concrete subclasses to call. 67 */ 68 protected AbstractTypeVisitor6() {} 69 70 /** 71 * Visits any type mirror as if by passing itself to that type 72 * mirror's {@link TypeMirror#accept accept} method. The 73 * invocation {@code v.visit(t, p)} is equivalent to {@code 74 * t.accept(v, p)}. 75 * 76 * @param t the type to visit 77 * @param p a visitor-specified parameter 78 * @return a visitor-specified result 79 */ 80 public final R visit(TypeMirror t, P p) { 81 return t.accept(this, p); 82 } 83 84 /** 85 * Visits any type mirror as if by passing itself to that type 86 * mirror's {@link TypeMirror#accept accept} method and passing 87 * {@code null} for the additional parameter. The invocation 88 * {@code v.visit(t)} is equivalent to {@code t.accept(v, null)}. 89 * 90 * @param t the type to visit 91 * @return a visitor-specified result 92 */ 93 public final R visit(TypeMirror t) { 94 return t.accept(this, null); 95 } 96 97 /** 98 * {@inheritDoc} 99 * 100 * <p> The default implementation of this method in {@code 101 * AbstractTypeVisitor6} will always throw {@code 102 * UnknownTypeException}. This behavior is not required of a 103 * subclass. 104 * 105 * @param t the type to visit 106 * @return a visitor-specified result 107 * @throws UnknownTypeException 108 * a visitor implementation may optionally throw this exception 109 */ 110 public R visitUnknown(TypeMirror t, P p) { 111 throw new UnknownTypeException(t, p); 112 } 113 }