simpleannotationvaluevisitor6.java

java1.6众多例子参考

/*
 * @(#)SimpleAnnotationValueVisitor6.java	1.6 06/08/15
 *
 * Copyright 2006 Sun Microsystems, Inc. All rights reserved.
 * SUN PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 */

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.
 *
 * @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;
 * @version 1.6 06/08/15
 * @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);
    }    
}