AbstractAnnotationValueVisitor9.java

/*
 * Copyright (c) 2011, 2018, 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 javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;

import static javax.lang.model.SourceVersion.RELEASE_11;

/**
 * A skeletal visitor for annotation values with default behavior
 * appropriate for source versions {@link SourceVersion#RELEASE_9
 * RELEASE_9} through {@link SourceVersion#RELEASE_11 RELEASE_11}.
 *
 * <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 abstract 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.
 *
 * @param <R> the return type of this visitor's methods
 * @param <P> the type of the additional parameter to this visitor's methods.
 *
 * @see AbstractAnnotationValueVisitor6
 * @see AbstractAnnotationValueVisitor7
 * @see AbstractAnnotationValueVisitor8
 * @since 9
 */
// 注解值访问器的抽象实现（JDK9）
@SupportedSourceVersion(RELEASE_11)
public abstract class AbstractAnnotationValueVisitor9<R, P> extends AbstractAnnotationValueVisitor8<R, P> {
    
    /**
     * Constructor for concrete subclasses to call.
     */
    protected AbstractAnnotationValueVisitor9() {
        super();
    }
}