/*

 * 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

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 */

package java.nio.file;

import java.nio.file.attribute.BasicFileAttributes;

import java.io.IOException;

import java.util.Objects;

/**

 * A simple visitor of files with default behavior to visit all files and to

 * re-throw I/O errors.

 *

 * <p> Methods in this class may be overridden subject to their general contract.

 *

 * @param   <T>     The type of reference to the files

 *

 * @since 1.7

 */

public class SimpleFileVisitor<T> implements FileVisitor<T> {

    /**

     * Initializes a new instance of this class.

     */

    protected SimpleFileVisitor() {

    }

    /**

     * Invoked for a directory before entries in the directory are visited.

     *

     * <p> Unless overridden, this method returns {@link FileVisitResult#CONTINUE

     * CONTINUE}.

     */

    @Override

    public FileVisitResult preVisitDirectory(T dir, BasicFileAttributes attrs)

        throws IOException

    {

        Objects.requireNonNull(dir);

        Objects.requireNonNull(attrs);

        return FileVisitResult.CONTINUE;

    }

    /**

     * Invoked for a file in a directory.

     *

     * <p> Unless overridden, this method returns {@link FileVisitResult#CONTINUE

     * CONTINUE}.

     */

    @Override

    public FileVisitResult visitFile(T file, BasicFileAttributes attrs)

        throws IOException

    {

        Objects.requireNonNull(file);

        Objects.requireNonNull(attrs);

        return FileVisitResult.CONTINUE;

    }

    /**

     * Invoked for a file that could not be visited.

     *

     * <p> Unless overridden, this method re-throws the I/O exception that prevented

     * the file from being visited.

     */

    @Override

    public FileVisitResult visitFileFailed(T file, IOException exc)

        throws IOException

    {

        Objects.requireNonNull(file);

        throw exc;

    }

    /**

     * Invoked for a directory after entries in the directory, and all of their

     * descendants, have been visited.

     *

     * <p> Unless overridden, this method returns {@link FileVisitResult#CONTINUE

     * CONTINUE} if the directory iteration completes without an I/O exception;

     * otherwise this method re-throws the I/O exception that caused the iteration

     * of the directory to terminate prematurely.

     */

    @Override

    public FileVisitResult postVisitDirectory(T dir, IOException exc)

        throws IOException

    {

        Objects.requireNonNull(dir);

        if (exc != null)

            throw exc;

        return FileVisitResult.CONTINUE;

    }

}