jdk8-mips64-public/langtools: src/share/classes/javax/lang/model/util/SimpleAnnotationValueVisitor6.java@09f65aad4759 (annotated)

src/share/classes/javax/lang/model/util/SimpleAnnotationValueVisitor6.java@09f65aad4759 (annotated)

src/share/classes/javax/lang/model/util/SimpleAnnotationValueVisitor6.java

Wed, 23 Jan 2013 20:11:07 -0800

author: darcy
date: Wed, 23 Jan 2013 20:11:07 -0800
changeset 1522: 09f65aad4759
parent 1054: 111bbf1ad913
child 2525: 2eb010b6cb22
permissions: -rw-r--r--

8006264: Add explanation of why default methods cannot be used in JDK 8 javax.lang.model
Reviewed-by: jjg

 /*
  * Copyright (c) 2005, 2013, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */
 package javax.lang.model.util;
 import java.util.List;
 import javax.lang.model.element.*;
 import javax.lang.model.type.TypeMirror;
 import static javax.lang.model.SourceVersion.*;
 import javax.lang.model.SourceVersion;
 import javax.annotation.processing.SupportedSourceVersion;
 /**
  * A simple visitor for annotation values with default behavior
  * appropriate for the {@link SourceVersion#RELEASE_6 RELEASE_6}
  * source version.  Visit methods call {@link
  * #defaultAction} passing their arguments to {@code defaultAction}'s
  * corresponding parameters.
  *
  * <p> Methods in this class may be overridden subject to their
  * general contract.  Note that annotating methods in concrete
  * subclasses with {@link java.lang.Override @Override} will help
  * ensure that methods are overridden as intended.
  *
  * <p> <b>WARNING:</b> The {@code AnnotationValueVisitor} interface
  * implemented by this class may have methods added to it in the
  * future to accommodate new, currently unknown, language structures
  * added to future versions of the Java&trade; programming language.
  * Therefore, methods whose names begin with {@code "visit"} may be
  * added to this class in the future; to avoid incompatibilities,
  * classes which extend this class should not declare any instance
  * methods with names beginning with {@code "visit"}.
  *
  * <p>When such a new visit method is added, the default
  * implementation in this class will be to call the {@link
  * #visitUnknown visitUnknown} method.  A new simple annotation
  * value visitor class will also be introduced to correspond to the
  * new language level; this visitor will have different default
  * behavior for the visit method in question.  When the new visitor is
  * introduced, all or portions of this visitor may be deprecated.
  *
  * <p>Note that adding a default implementation of a new visit method
  * in a visitor class will occur instead of adding a <em>default
  * method</em> directly in the visitor interface since a Java SE 8
  * language feature cannot be used to this version of the API since
  * this version is required to be runnable on Java SE 7
  * implementations.  Future versions of the API that are only required
  * to run on Java SE 8 and later may take advantage of default methods
  * in this situation.
  *
  * @param <R> the return type of this visitor's methods
  * @param <P> the type of the additional parameter to this visitor's methods.
  *
  * @author Joseph D. Darcy
  * @author Scott Seligman
  * @author Peter von der Ah&eacute;
  *
  * @see SimpleAnnotationValueVisitor7
  * @see SimpleAnnotationValueVisitor8
  * @since 1.6
  */
 @SupportedSourceVersion(RELEASE_6)
 public class SimpleAnnotationValueVisitor6<R, P>
     extends AbstractAnnotationValueVisitor6<R, P> {
     /**
      * Default value to be returned; {@link #defaultAction
      * defaultAction} returns this value unless the method is
      * overridden.
      */
     protected final R DEFAULT_VALUE;
     /**
      * Constructor for concrete subclasses; uses {@code null} for the
      * default value.
      */
     protected SimpleAnnotationValueVisitor6() {
         super();
         DEFAULT_VALUE = null;
     }
     /**
      * Constructor for concrete subclasses; uses the argument for the
      * default value.
      *
      * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
      */
     protected SimpleAnnotationValueVisitor6(R defaultValue) {
         super();
         DEFAULT_VALUE = defaultValue;
     }
     /**
      * The default action for visit methods.  The implementation in
      * this class just returns {@link #DEFAULT_VALUE}; subclasses will
      * commonly override this method.
      *
      * @param o the value of the annotation
      * @param p a visitor-specified parameter
      * @return {@code DEFAULT_VALUE} unless overridden
      */
     protected R defaultAction(Object o, P p) {
         return DEFAULT_VALUE;
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param b {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitBoolean(boolean b, P p) {
         return defaultAction(b, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param b {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitByte(byte b, P p) {
         return defaultAction(b, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param c {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitChar(char c, P p) {
         return defaultAction(c, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param d {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitDouble(double d, P p) {
         return defaultAction(d, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param f {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitFloat(float f, P p) {
         return defaultAction(f, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param i {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitInt(int i, P p) {
         return defaultAction(i, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param i {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitLong(long i, P p) {
         return defaultAction(i, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param s {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitShort(short s, P p) {
         return defaultAction(s, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param s {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitString(String s, P p) {
         return defaultAction(s, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param t {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitType(TypeMirror t, P p) {
         return defaultAction(t, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param c {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitEnumConstant(VariableElement c, P p) {
         return defaultAction(c, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param a {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitAnnotation(AnnotationMirror a, P p) {
         return defaultAction(a, p);
     }
     /**
      * {@inheritDoc} This implementation calls {@code defaultAction}.
      *
      * @param vals {@inheritDoc}
      * @param p {@inheritDoc}
      * @return  the result of {@code defaultAction}
      */
     public R visitArray(List<? extends AnnotationValue> vals, P p) {
         return defaultAction(vals, p);
     }
 }

Mercurial > jdk8-mips64-public > langtools / annotate

src/share/classes/javax/lang/model/util/SimpleAnnotationValueVisitor6.java@09f65aad4759 (annotated)

src/share/classes/javax/lang/model/util/SimpleAnnotationValueVisitor6.java