1 /*

     2  * Copyright (c) 2009, 2013, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package sun.nio.fs;

    27 

    28 import java.util.*;

    29 import java.nio.file.*;

    30 import java.nio.charset.Charset;

    31 import java.security.*;

    32 import sun.security.action.*;

    33 

    34 /**

    35  * Utility methods

    36  */

    37 

    38 class Util {

    39     private Util() { }

    40 

    41     private static final Charset jnuEncoding = Charset.forName(

    42         AccessController.doPrivileged(new GetPropertyAction("sun.jnu.encoding")));

    43 

    44     /**

    45      * Returns {@code Charset} corresponding to the sun.jnu.encoding property

    46      */

    47     static Charset jnuEncoding() {

    48         return jnuEncoding;

    49     }

    50 

    51     /**

    52      * Encodes the given String into a sequence of bytes using the {@code Charset}

    53      * specified by the sun.jnu.encoding property.

    54      */

    55     static byte[] toBytes(String s) {

    56         return s.getBytes(jnuEncoding);

    57     }

    58 

    59     /**

    60      * Constructs a new String by decoding the specified array of bytes using the

    61      * {@code Charset} specified by the sun.jnu.encoding property.

    62      */

    63     static String toString(byte[] bytes) {

    64         return new String(bytes, jnuEncoding);

    65     }

    66 

    67 

    68     /**

    69      * Splits a string around the given character. The array returned by this

    70      * method contains each substring that is terminated by the character. Use

    71      * for simple string spilting cases when needing to avoid loading regex.

    72      */

    73     static String[] split(String s, char c) {

    74         int count = 0;

    75         for (int i=0; i<s.length(); i++) {

    76             if (s.charAt(i) == c)

    77                 count++;

    78         }

    79         String[] result = new String[count+1];

    80         int n = 0;

    81         int last = 0;

    82         for (int i=0; i<s.length(); i++) {

    83             if (s.charAt(i) == c) {

    84                 result[n++] = s.substring(last, i);

    85                 last = i + 1;

    86             }

    87         }

    88         result[n] = s.substring(last, s.length());

    89         return result;

    90     }

    91 

    92     /**

    93      * Returns a Set containing the given elements.

    94      */

    95     @SafeVarargs

    96     static <E> Set<E> newSet(E... elements) {

    97         HashSet<E> set = new HashSet<>();

    98         for (E e: elements) {

    99             set.add(e);

   100         }

   101         return set;

   102     }

   103 

   104     /**

   105      * Returns a Set containing all the elements of the given Set plus

   106      * the given elements.

   107      */

   108     @SafeVarargs

   109     static <E> Set<E> newSet(Set<E> other, E... elements) {

   110         HashSet<E> set = new HashSet<>(other);

   111         for (E e: elements) {

   112             set.add(e);

   113         }

   114         return set;

   115     }

   116 

   117     /**

   118      * Returns {@code true} if symbolic links should be followed

   119      */

   120     static boolean followLinks(LinkOption... options) {

   121         boolean followLinks = true;

   122         for (LinkOption option: options) {

   123             if (option == LinkOption.NOFOLLOW_LINKS) {

   124                 followLinks = false;

   125             } else if (option == null) {

   126                 throw new NullPointerException();

   127             } else {

   128                 throw new AssertionError("Should not get here");

   129             }

   130         }

   131         return followLinks;

   132     }

   133 }