1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
|
/*
* Copyright (C) 2009 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.util;
import android.os.Build;
import android.text.TextUtils;
import java.nio.charset.Charset;
import java.nio.charset.IllegalCharsetNameException;
import java.nio.charset.UnsupportedCharsetException;
import java.util.HashMap;
import java.util.Map;
/**
* <p>
* A class containing utility methods related to character sets. This
* class is primarily useful for code that wishes to be vendor-aware
* in its interpretation of Japanese charset names (used in DoCoMo,
* KDDI, and SoftBank).
* </p>
*
* <p>
* <b>Note:</b> Developers will need to add an appropriate mapping for
* each vendor-specific charset. You may need to modify the C libraries
* like icu4c in order to let Android support an additional charset.
* </p>
*
* @hide
*/
public final class CharsetUtils {
/**
* name of the vendor "DoCoMo". <b>Note:</b> This isn't a public
* constant, in order to keep this class from becoming a de facto
* reference list of vendor names.
*/
private static final String VENDOR_DOCOMO = "docomo";
/**
* Name of the vendor "KDDI".
*/
private static final String VENDOR_KDDI = "kddi";
/**
* Name of the vendor "SoftBank".
*/
private static final String VENDOR_SOFTBANK = "softbank";
/**
* Represents one-to-one mapping from a vendor name to a charset specific to the vendor.
*/
private static final Map<String, String> sVendorShiftJisMap = new HashMap<String, String>();
static {
// These variants of Shift_JIS come from icu's mapping data (convrtrs.txt)
sVendorShiftJisMap.put(VENDOR_DOCOMO, "docomo-shift_jis-2007");
sVendorShiftJisMap.put(VENDOR_KDDI, "kddi-shift_jis-2007");
sVendorShiftJisMap.put(VENDOR_SOFTBANK, "softbank-shift_jis-2007");
}
/**
* This class is uninstantiable.
*/
private CharsetUtils() {
// This space intentionally left blank.
}
/**
* Returns the name of the vendor-specific character set
* corresponding to the given original character set name and
* vendor. If there is no vendor-specific character set for the
* given name/vendor pair, this returns the original character set name.
*
* @param charsetName the base character set name
* @param vendor the vendor to specialize for. All characters should be lower-cased.
* @return the specialized character set name, or {@code charsetName} if
* there is no specialized name
*/
public static String nameForVendor(String charsetName, String vendor) {
if (!TextUtils.isEmpty(charsetName) && !TextUtils.isEmpty(vendor)) {
// You can add your own mapping here.
if (isShiftJis(charsetName)) {
final String vendorShiftJis = sVendorShiftJisMap.get(vendor);
if (vendorShiftJis != null) {
return vendorShiftJis;
}
}
}
return charsetName;
}
/**
* Returns the name of the vendor-specific character set
* corresponding to the given original character set name and the
* default vendor (that is, the targeted vendor of the device this
* code is running on). This method merely calls through to
* {@link #nameForVendor(String,String)}, passing the default vendor
* as the second argument.
*
* @param charsetName the base character set name
* @return the specialized character set name, or {@code charsetName} if
* there is no specialized name
*/
public static String nameForDefaultVendor(String charsetName) {
return nameForVendor(charsetName, getDefaultVendor());
}
/**
* Returns the vendor-specific character set corresponding to the
* given original character set name and vendor. If there is no
* vendor-specific character set for the given name/vendor pair,
* this returns the character set corresponding to the original
* name. The vendor name is matched case-insensitively. This
* method merely calls {@code Charset.forName()} on a name
* transformed by a call to {@link #nameForVendor(String,String)}.
*
* @param charsetName the base character set name
* @param vendor the vendor to specialize for
* @return the specialized character set, or the one corresponding
* directly to {@code charsetName} if there is no specialized
* variant
* @throws UnsupportedCharsetException thrown if the named character
* set is not supported by the system
* @throws IllegalCharsetNameException thrown if {@code charsetName}
* has invalid syntax
*/
public static Charset charsetForVendor(String charsetName, String vendor)
throws UnsupportedCharsetException, IllegalCharsetNameException {
charsetName = nameForVendor(charsetName, vendor);
return Charset.forName(charsetName);
}
/**
* Returns the vendor-specific character set corresponding to the
* given original character set name and default vendor (that is,
* the targeted vendor of the device this code is running on).
* This method merely calls through to {@link
* #charsetForVendor(String,String)}, passing the default vendor
* as the second argument.
*
* @param charsetName the base character set name
* @return the specialized character set, or the one corresponding
* directly to {@code charsetName} if there is no specialized
* variant
* @throws UnsupportedCharsetException thrown if the named character
* set is not supported by the system
* @throws IllegalCharsetNameException thrown if {@code charsetName}
* has invalid syntax
*/
public static Charset charsetForVendor(String charsetName)
throws UnsupportedCharsetException, IllegalCharsetNameException {
return charsetForVendor(charsetName, getDefaultVendor());
}
/**
* Returns whether the given character set name indicates the Shift-JIS
* encoding. Returns false if the name is null.
*
* @param charsetName the character set name
* @return {@code true} if the name corresponds to Shift-JIS or
* {@code false} if not
*/
private static boolean isShiftJis(String charsetName) {
// Bail quickly if the length doesn't match.
if (charsetName == null) {
return false;
}
int length = charsetName.length();
if (length != 4 && length != 9) {
return false;
}
return charsetName.equalsIgnoreCase("shift_jis")
|| charsetName.equalsIgnoreCase("shift-jis")
|| charsetName.equalsIgnoreCase("sjis");
}
/**
* Gets the default vendor for this build.
*
* @return the default vendor name
*/
private static String getDefaultVendor() {
return Build.BRAND;
}
}
|
