Java example source code file (Chmod.java)

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Java - Java tags/keywords

basicfileattributes, changer, continue, filevisitor, filevisitresult, hashset, illegalargumentexception, invalid, ioexception, override, path, set, string, treevisitor, util

The Chmod.java Java example source code

/*
 * Copyright (c) 2008, 2011, Oracle and/or its affiliates. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *   - Redistributions of source code must retain the above copyright
 *     notice, this list of conditions and the following disclaimer.
 *
 *   - Redistributions in binary form must reproduce the above copyright
 *     notice, this list of conditions and the following disclaimer in the
 *     documentation and/or other materials provided with the distribution.
 *
 *   - Neither the name of Oracle nor the names of its
 *     contributors may be used to endorse or promote products derived
 *     from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
 * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/*
 * This source code is provided to illustrate the usage of a given feature
 * or technique and has been deliberately simplified. Additional steps
 * required for a production-quality application, such as security checks,
 * input validation and proper error handling, might not be present in
 * this sample code.
 */


import java.nio.file.*;
import java.nio.file.attribute.*;
import static java.nio.file.attribute.PosixFilePermission.*;
import static java.nio.file.FileVisitResult.*;
import java.io.IOException;
import java.util.*;

/**
 * Sample code that changes the permissions of files in a similar manner to the
 * chmod(1) program.
 */

public class Chmod {

    /**
     * Compiles a list of one or more <em>symbolic mode expressions that
     * may be used to change a set of file permissions. This method is
     * intended for use where file permissions are required to be changed in
     * a manner similar to the UNIX <i>chmod program.
     *
     * <p> The {@code exprs} parameter is a comma separated list of expressions
     * where each takes the form:
     * <blockquote>
     * <i>who operator [permissions]
     * </blockquote>
     * where <i>who is one or more of the characters {@code 'u'}, {@code 'g'},
     * {@code 'o'}, or {@code 'a'} meaning the owner (user), group, others, or
     * all (owner, group, and others) respectively.
     *
     * <p> operator is the character {@code '+'}, {@code '-'}, or {@code
     * '='} signifying how permissions are to be changed. {@code '+'} means the
     * permissions are added, {@code '-'} means the permissions are removed, and
     * {@code '='} means the permissions are assigned absolutely.
     *
     * <p> permissions is a sequence of zero or more of the following:
     * {@code 'r'} for read permission, {@code 'w'} for write permission, and
     * {@code 'x'} for execute permission. If <i>permissions is omitted
     * when assigned absolutely, then the permissions are cleared for
     * the owner, group, or others as identified by <i>who. When omitted
     * when adding or removing then the expression is ignored.
     *
     * <p> The following examples demonstrate possible values for the {@code
     * exprs} parameter:
     *
     * <table border="0">
     * <tr>
     *   <td> {@code u=rw}