Java example source code file (TypeKindVisitor6.java)

This example Java source code file (TypeKindVisitor6.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

assertionerror, bad, boolean, char, double, long, override, package, short, supportedsourceversion, typekindvisitor6, void

The TypeKindVisitor6.java Java example source code

/*
 * 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 javax.annotation.processing.SupportedSourceVersion;
import javax.lang.model.SourceVersion;
import javax.lang.model.type.*;
import static javax.lang.model.SourceVersion.*;

/**
 * A visitor of types based on their {@linkplain TypeKind kind} with
 * default behavior appropriate for the {@link SourceVersion#RELEASE_6
 * RELEASE_6} source version.  For {@linkplain
 * TypeMirror types} <tt>XYZ that may have more than one
 * kind, the <tt>visitXYZ methods in this class delegate
 * to the <tt>visitXYZKind method corresponding to the
 * first argument's kind.  The <tt>visitXYZKind methods
 * call {@link #defaultAction 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> WARNING: The {@code TypeVisitor} 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™ 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 type kind 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.  Use {@link
 *            Void} for visitors that do not need to return results.
 * @param <P> the type of the additional parameter to this visitor's
 *            methods.  Use {@code Void} for visitors that do not need an
 *            additional parameter.
 *
 * @author Joseph D. Darcy
 * @author Scott Seligman
 * @author Peter von der Ahé
 *
 * @see TypeKindVisitor7
 * @see TypeKindVisitor8
 * @since 1.6
 */
@SupportedSourceVersion(RELEASE_6)
public class TypeKindVisitor6<R, P> extends SimpleTypeVisitor6 {
    /**
     * Constructor for concrete subclasses to call; uses {@code null}
     * for the default value.
     */
    protected TypeKindVisitor6() {
        super(null);
    }


    /**
     * Constructor for concrete subclasses to call; uses the argument
     * for the default value.
     *
     * @param defaultValue the value to assign to {@link #DEFAULT_VALUE}
     */
    protected TypeKindVisitor6(R defaultValue) {
        super(defaultValue);
    }

    /**
     * Visits a primitive type, dispatching to the visit method for
     * the specific {@linkplain TypeKind kind} of primitive type:
     * {@code BOOLEAN}, {@code BYTE}, etc.
     *
     * @param t {@inheritDoc}
     * @param p {@inheritDoc}
     * @return  the result of the kind-specific visit method
     */
    @Override
    public R visitPrimitive(PrimitiveType t, P p) {
        TypeKind k = t.getKind();
        switch (k) {
        case BOOLEAN:
            return visitPrimitiveAsBoolean(t, p);

        case BYTE:
            return visitPrimitiveAsByte(t, p);

        case SHORT:
            return visitPrimitiveAsShort(t, p);

        case INT:
            return visitPrimitiveAsInt(t, p);

        case LONG:
            return visitPrimitiveAsLong(t, p);

        case CHAR:
            return visitPrimitiveAsChar(t, p);

        case FLOAT:
            return visitPrimitiveAsFloat(t, p);

        case DOUBLE:
            return visitPrimitiveAsDouble(t, p);

        default:
            throw new AssertionError("Bad kind " + k + " for PrimitiveType" + t);
        }
    }

    /**
     * Visits a {@code BOOLEAN} primitive type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitPrimitiveAsBoolean(PrimitiveType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@code BYTE} primitive type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitPrimitiveAsByte(PrimitiveType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@code SHORT} primitive type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitPrimitiveAsShort(PrimitiveType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits an {@code INT} primitive type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitPrimitiveAsInt(PrimitiveType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@code LONG} primitive type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitPrimitiveAsLong(PrimitiveType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@code CHAR} primitive type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitPrimitiveAsChar(PrimitiveType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@code FLOAT} primitive type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitPrimitiveAsFloat(PrimitiveType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@code DOUBLE} primitive type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitPrimitiveAsDouble(PrimitiveType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@link NoType} instance, dispatching to the visit method for
     * the specific {@linkplain TypeKind kind} of pseudo-type:
     * {@code VOID}, {@code PACKAGE}, or {@code NONE}.
     *
     * @param t {@inheritDoc}
     * @param p {@inheritDoc}
     * @return  the result of the kind-specific visit method
     */
    @Override
    public R visitNoType(NoType t, P p) {
        TypeKind k = t.getKind();
        switch (k) {
        case VOID:
            return visitNoTypeAsVoid(t, p);

        case PACKAGE:
            return visitNoTypeAsPackage(t, p);

        case NONE:
            return visitNoTypeAsNone(t, p);

        default:
            throw new AssertionError("Bad kind " + k + " for NoType" + t);
        }
    }

    /**
     * Visits a {@link TypeKind#VOID VOID} pseudo-type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitNoTypeAsVoid(NoType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@link TypeKind#PACKAGE PACKAGE} pseudo-type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitNoTypeAsPackage(NoType t, P p) {
        return defaultAction(t, p);
    }

    /**
     * Visits a {@link TypeKind#NONE NONE} pseudo-type by calling
     * {@code defaultAction}.
     *
     * @param t the type to visit
     * @param p a visitor-specified parameter
     * @return  the result of {@code defaultAction}
     */
    public R visitNoTypeAsNone(NoType t, P p) {
        return defaultAction(t, p);
    }
}