Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
UnicodeReader |
|
| 3.0;3 |
1 | /** | |
2 | * Copyright (c) 2008-2011, http://www.snakeyaml.org | |
3 | * | |
4 | * Licensed under the Apache License, Version 2.0 (the "License"); | |
5 | * you may not use this file except in compliance with the License. | |
6 | * You may obtain a copy of the License at | |
7 | * | |
8 | * http://www.apache.org/licenses/LICENSE-2.0 | |
9 | * | |
10 | * Unless required by applicable law or agreed to in writing, software | |
11 | * distributed under the License is distributed on an "AS IS" BASIS, | |
12 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. | |
13 | * See the License for the specific language governing permissions and | |
14 | * limitations under the License. | |
15 | */ | |
16 | ||
17 | package org.yaml.snakeyaml.reader; | |
18 | ||
19 | /** | |
20 | version: 1.1 / 2007-01-25 | |
21 | - changed BOM recognition ordering (longer boms first) | |
22 | ||
23 | Original pseudocode : Thomas Weidenfeller | |
24 | Implementation tweaked: Aki Nieminen | |
25 | Implementation changed: Andrey Somov | |
26 | * UTF-32 removed because it is not supported by YAML | |
27 | * no default encoding | |
28 | ||
29 | http://www.unicode.org/unicode/faq/utf_bom.html | |
30 | BOMs: | |
31 | 00 00 FE FF = UTF-32, big-endian | |
32 | FF FE 00 00 = UTF-32, little-endian | |
33 | EF BB BF = UTF-8, | |
34 | FE FF = UTF-16, big-endian | |
35 | FF FE = UTF-16, little-endian | |
36 | ||
37 | Win2k Notepad: | |
38 | Unicode format = UTF-16LE | |
39 | ***/ | |
40 | ||
41 | import java.io.IOException; | |
42 | import java.io.InputStream; | |
43 | import java.io.InputStreamReader; | |
44 | import java.io.PushbackInputStream; | |
45 | import java.io.Reader; | |
46 | ||
47 | /** | |
48 | * Generic unicode textreader, which will use BOM mark to identify the encoding | |
49 | * to be used. If BOM is not found then use a given default or system encoding. | |
50 | */ | |
51 | public class UnicodeReader extends Reader { | |
52 | PushbackInputStream internalIn; | |
53 | 1342 | InputStreamReader internalIn2 = null; |
54 | ||
55 | private static final int BOM_SIZE = 3; | |
56 | ||
57 | /** | |
58 | * @param in | |
59 | * InputStream to be read | |
60 | */ | |
61 | 1342 | public UnicodeReader(InputStream in) { |
62 | 1342 | internalIn = new PushbackInputStream(in, BOM_SIZE); |
63 | 1342 | } |
64 | ||
65 | /** | |
66 | * Get stream encoding or NULL if stream is uninitialized. Call init() or | |
67 | * read() method to initialize it. | |
68 | */ | |
69 | public String getEncoding() { | |
70 | 4 | return internalIn2.getEncoding(); |
71 | } | |
72 | ||
73 | /** | |
74 | * Read-ahead four bytes and check for BOM marks. Extra bytes are unread | |
75 | * back to the stream, only BOM bytes are skipped. | |
76 | */ | |
77 | protected void init() throws IOException { | |
78 | 2659 | if (internalIn2 != null) |
79 | 1317 | return; |
80 | ||
81 | String encoding; | |
82 | 1342 | byte bom[] = new byte[BOM_SIZE]; |
83 | int n, unread; | |
84 | 1342 | n = internalIn.read(bom, 0, bom.length); |
85 | ||
86 | 1341 | if ((bom[0] == (byte) 0xEF) && (bom[1] == (byte) 0xBB) && (bom[2] == (byte) 0xBF)) { |
87 | 2 | encoding = "UTF-8"; |
88 | 2 | unread = n - 3; |
89 | 1339 | } else if ((bom[0] == (byte) 0xFE) && (bom[1] == (byte) 0xFF)) { |
90 | 2 | encoding = "UTF-16BE"; |
91 | 2 | unread = n - 2; |
92 | 1337 | } else if ((bom[0] == (byte) 0xFF) && (bom[1] == (byte) 0xFE)) { |
93 | 1 | encoding = "UTF-16LE"; |
94 | 1 | unread = n - 2; |
95 | } else { | |
96 | // Unicode BOM mark not found, unread all bytes | |
97 | 1336 | encoding = "UTF-8"; |
98 | 1336 | unread = n; |
99 | } | |
100 | ||
101 | 1341 | if (unread > 0) |
102 | 1334 | internalIn.unread(bom, (n - unread), unread); |
103 | ||
104 | // Use given encoding | |
105 | 1341 | internalIn2 = new InputStreamReader(internalIn, encoding); |
106 | 1341 | } |
107 | ||
108 | public void close() throws IOException { | |
109 | 1 | init(); |
110 | 1 | internalIn2.close(); |
111 | 1 | } |
112 | ||
113 | public int read(char[] cbuf, int off, int len) throws IOException { | |
114 | 2658 | init(); |
115 | 2657 | return internalIn2.read(cbuf, off, len); |
116 | } | |
117 | } |