1 /*
2 * Copyright 2012 The Netty Project
3 *
4 * The Netty Project licenses this file to you under the Apache License,
5 * version 2.0 (the "License"); you may not use this file except in compliance
6 * with the License. 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, WITHOUT
12 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
13 * License for the specific language governing permissions and limitations
14 * under the License.
15 */
16 package io.netty.util;
17
18 import io.netty.util.internal.InternalThreadLocalMap;
19 import static io.netty.util.internal.ObjectUtil.checkNotNull;
20
21 import java.nio.charset.Charset;
22 import java.nio.charset.CharsetDecoder;
23 import java.nio.charset.CharsetEncoder;
24 import java.nio.charset.CodingErrorAction;
25 import java.util.Map;
26
27 /**
28 * A utility class that provides various common operations and constants
29 * related with {@link Charset} and its relevant classes.
30 */
31 public final class CharsetUtil {
32
33 /**
34 * 16-bit UTF (UCS Transformation Format) whose byte order is identified by
35 * an optional byte-order mark
36 */
37 public static final Charset UTF_16 = Charset.forName("UTF-16");
38
39 /**
40 * 16-bit UTF (UCS Transformation Format) whose byte order is big-endian
41 */
42 public static final Charset UTF_16BE = Charset.forName("UTF-16BE");
43
44 /**
45 * 16-bit UTF (UCS Transformation Format) whose byte order is little-endian
46 */
47 public static final Charset UTF_16LE = Charset.forName("UTF-16LE");
48
49 /**
50 * 8-bit UTF (UCS Transformation Format)
51 */
52 public static final Charset UTF_8 = Charset.forName("UTF-8");
53
54 /**
55 * ISO Latin Alphabet No. 1, as known as <tt>ISO-LATIN-1</tt>
56 */
57 public static final Charset ISO_8859_1 = Charset.forName("ISO-8859-1");
58
59 /**
60 * 7-bit ASCII, as known as ISO646-US or the Basic Latin block of the
61 * Unicode character set
62 */
63 public static final Charset US_ASCII = Charset.forName("US-ASCII");
64
65 /**
66 * @deprecated Use {@link #encoder(Charset)}.
67 */
68 @Deprecated
69 public static CharsetEncoder getEncoder(Charset charset) {
70 return encoder(charset);
71 }
72
73 /**
74 * Returns a new {@link CharsetEncoder} for the {@link Charset} with specified error actions.
75 *
76 * @param charset The specified charset
77 * @param malformedInputAction The encoder's action for malformed-input errors
78 * @param unmappableCharacterAction The encoder's action for unmappable-character errors
79 * @return The encoder for the specified {@code charset}
80 */
81 public static CharsetEncoder encoder(Charset charset, CodingErrorAction malformedInputAction,
82 CodingErrorAction unmappableCharacterAction) {
83 checkNotNull(charset, "charset");
84 CharsetEncoder e = charset.newEncoder();
85 e.onMalformedInput(malformedInputAction).onUnmappableCharacter(unmappableCharacterAction);
86 return e;
87 }
88
89 /**
90 * Returns a new {@link CharsetEncoder} for the {@link Charset} with the specified error action.
91 *
92 * @param charset The specified charset
93 * @param codingErrorAction The encoder's action for malformed-input and unmappable-character errors
94 * @return The encoder for the specified {@code charset}
95 */
96 public static CharsetEncoder encoder(Charset charset, CodingErrorAction codingErrorAction) {
97 return encoder(charset, codingErrorAction, codingErrorAction);
98 }
99
100 /**
101 * Returns a cached thread-local {@link CharsetEncoder} for the specified {@link Charset}.
102 *
103 * @param charset The specified charset
104 * @return The encoder for the specified {@code charset}
105 */
106 public static CharsetEncoder encoder(Charset charset) {
107 checkNotNull(charset, "charset");
108
109 Map<Charset, CharsetEncoder> map = InternalThreadLocalMap.get().charsetEncoderCache();
110 CharsetEncoder e = map.get(charset);
111 if (e != null) {
112 e.reset().onMalformedInput(CodingErrorAction.REPLACE).onUnmappableCharacter(CodingErrorAction.REPLACE);
113 return e;
114 }
115
116 e = encoder(charset, CodingErrorAction.REPLACE, CodingErrorAction.REPLACE);
117 map.put(charset, e);
118 return e;
119 }
120
121 /**
122 * @deprecated Use {@link #decoder(Charset)}.
123 */
124 @Deprecated
125 public static CharsetDecoder getDecoder(Charset charset) {
126 return decoder(charset);
127 }
128
129 /**
130 * Returns a new {@link CharsetDecoder} for the {@link Charset} with specified error actions.
131 *
132 * @param charset The specified charset
133 * @param malformedInputAction The decoder's action for malformed-input errors
134 * @param unmappableCharacterAction The decoder's action for unmappable-character errors
135 * @return The decoder for the specified {@code charset}
136 */
137 public static CharsetDecoder decoder(Charset charset, CodingErrorAction malformedInputAction,
138 CodingErrorAction unmappableCharacterAction) {
139 checkNotNull(charset, "charset");
140 CharsetDecoder d = charset.newDecoder();
141 d.onMalformedInput(malformedInputAction).onUnmappableCharacter(unmappableCharacterAction);
142 return d;
143 }
144
145 /**
146 * Returns a new {@link CharsetDecoder} for the {@link Charset} with the specified error action.
147 *
148 * @param charset The specified charset
149 * @param codingErrorAction The decoder's action for malformed-input and unmappable-character errors
150 * @return The decoder for the specified {@code charset}
151 */
152 public static CharsetDecoder decoder(Charset charset, CodingErrorAction codingErrorAction) {
153 return decoder(charset, codingErrorAction, codingErrorAction);
154 }
155
156 /**
157 * Returns a cached thread-local {@link CharsetDecoder} for the specified {@link Charset}.
158 *
159 * @param charset The specified charset
160 * @return The decoder for the specified {@code charset}
161 */
162 public static CharsetDecoder decoder(Charset charset) {
163 checkNotNull(charset, "charset");
164
165 Map<Charset, CharsetDecoder> map = InternalThreadLocalMap.get().charsetDecoderCache();
166 CharsetDecoder d = map.get(charset);
167 if (d != null) {
168 d.reset().onMalformedInput(CodingErrorAction.REPLACE).onUnmappableCharacter(CodingErrorAction.REPLACE);
169 return d;
170 }
171
172 d = decoder(charset, CodingErrorAction.REPLACE, CodingErrorAction.REPLACE);
173 map.put(charset, d);
174 return d;
175 }
176
177 private CharsetUtil() {
178 // Unused
179 }
180 }