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
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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 {
Util()39     private Util() { }
40 
41     // Android-changed: Hard-code UTF-8 for jnuEncoding rather than requiring a system property.
42     // The system property sun.jnu.encoding is not set on Android; we just hard-code "UTF-8" here.
43     // private static final Charset jnuEncoding = Charset.forName(
44     //    AccessController.doPrivileged(new GetPropertyAction("sun.jnu.encoding")));
45     private static final Charset jnuEncoding = Charset.forName("UTF-8");
46 
47     /**
48      * Returns {@code Charset} corresponding to the sun.jnu.encoding property
49      */
jnuEncoding()50     static Charset jnuEncoding() {
51         return jnuEncoding;
52     }
53 
54     /**
55      * Encodes the given String into a sequence of bytes using the {@code Charset}
56      * specified by the sun.jnu.encoding property.
57      */
toBytes(String s)58     static byte[] toBytes(String s) {
59         return s.getBytes(jnuEncoding);
60     }
61 
62     /**
63      * Constructs a new String by decoding the specified array of bytes using the
64      * {@code Charset} specified by the sun.jnu.encoding property.
65      */
toString(byte[] bytes)66     static String toString(byte[] bytes) {
67         return new String(bytes, jnuEncoding);
68     }
69 
70 
71     /**
72      * Splits a string around the given character. The array returned by this
73      * method contains each substring that is terminated by the character. Use
74      * for simple string spilting cases when needing to avoid loading regex.
75      */
split(String s, char c)76     static String[] split(String s, char c) {
77         int count = 0;
78         for (int i=0; i<s.length(); i++) {
79             if (s.charAt(i) == c)
80                 count++;
81         }
82         String[] result = new String[count+1];
83         int n = 0;
84         int last = 0;
85         for (int i=0; i<s.length(); i++) {
86             if (s.charAt(i) == c) {
87                 result[n++] = s.substring(last, i);
88                 last = i + 1;
89             }
90         }
91         result[n] = s.substring(last, s.length());
92         return result;
93     }
94 
95     /**
96      * Returns a Set containing the given elements.
97      */
98     @SafeVarargs
newSet(E... elements)99     static <E> Set<E> newSet(E... elements) {
100         HashSet<E> set = new HashSet<>();
101         for (E e: elements) {
102             set.add(e);
103         }
104         return set;
105     }
106 
107     /**
108      * Returns a Set containing all the elements of the given Set plus
109      * the given elements.
110      */
111     @SafeVarargs
newSet(Set<E> other, E... elements)112     static <E> Set<E> newSet(Set<E> other, E... elements) {
113         HashSet<E> set = new HashSet<>(other);
114         for (E e: elements) {
115             set.add(e);
116         }
117         return set;
118     }
119 
120     /**
121      * Returns {@code true} if symbolic links should be followed
122      */
followLinks(LinkOption... options)123     static boolean followLinks(LinkOption... options) {
124         boolean followLinks = true;
125         for (LinkOption option: options) {
126             if (option == LinkOption.NOFOLLOW_LINKS) {
127                 followLinks = false;
128             } else if (option == null) {
129                 throw new NullPointerException();
130             } else {
131                 throw new AssertionError("Should not get here");
132             }
133         }
134         return followLinks;
135     }
136 }
137