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1
23 package org.enhydra.xml.io;
24
25 import java.io.BufferedReader  ;
26 import java.io.IOException ;
27 import java.io.InputStream ;
28 import java.io.InputStreamReader ;
29 import java.lang.reflect.Constructor ;
30 import java.util.HashMap ;
31 import java.util.Iterator ;
32 import java.util.StringTokenizer ;
33
34
38
41 public final class Encodings {
42
45 public static final String ISO_8859_1 = "ISO_8859-1";
46 public static final String US_ASCII = "US-ASCII";
47 public static final String SHIFT_JIS = "Shift_JIS";
48
49
52 private final String CHAR_SET_TABLE
53 = "org/enhydra/xml/io/character-sets.tbl";
54
55
58 private final String NULL_STR = "null";
59
60
63 private static Encodings fSingleton;
64
65
68 private static final String [] fEmptyAliases = new String [0];
69
70
74 private final HashMap fCharSets = new HashMap ();
75
76 private static final Class CHARSET_CONSTRUCTOR_TYPES[] = {
77 String .class, Integer.TYPE, String .class, String [].class
78 };
79
80
83 private void parseError(String msg,
84 String line) {
85 throw new XMLIOError(msg + "; parsing line in " + CHAR_SET_TABLE
86 + "\"" + line + "\"");
87 }
88
89
92 private CharacterSet parseCharSetEntry(String line) {
93 StringTokenizer tokens = new StringTokenizer (line);
94 int numTokens = tokens.countTokens();
95 if (numTokens < 4) {
96 parseError("must have at least 4 entries", line);
97 }
98
99 String className = tokens.nextToken();
100 String name = tokens.nextToken();
101 Integer charSetSize = null;
102 try {
103 charSetSize = new Integer (tokens.nextToken());
104 } catch (NumberFormatException nfe) {
105 parseError("invalid character set size", line);
106 }
107 String mimePreferred = tokens.nextToken();;
108 if (mimePreferred.equals(NULL_STR)) {
109 mimePreferred = null;
110 }
111 String [] aliases = fEmptyAliases;
112
113 if (numTokens > 4) {
114 aliases = new String [numTokens - 4];
115 int idx = 0;
116 while (tokens.hasMoreTokens()) {
117 aliases[idx++] = tokens.nextToken();
118 }
119 }
120
121 try {
123 Class clazz = Class.forName(className);
124 Constructor ctr = clazz.getConstructor(CHARSET_CONSTRUCTOR_TYPES);
125 Object params[] = { name, charSetSize, mimePreferred, aliases };
126 return (CharacterSet)ctr.newInstance(params);
127 } catch (Exception e) {
128 parseError("Exception loading character set class '" + className + "': " +
129 e.toString(), line);
130 }
131 throw new IllegalStateException ("Ooops. This should never happen. Please debug");
133 }
134
135
138 private void addEntry(CharacterSet charSet) {
139 fCharSets.put(charSet.getName().toUpperCase().intern(), charSet);
140
141 String [] aliases = charSet.getAliases();
142 int len = (aliases == null) ? 0 : aliases.length;
143 for (int idx = 0; idx < len; idx++) {
144 fCharSets.put(aliases[idx].toUpperCase().intern(), charSet);
145 }
146 }
147
148
151 private void parseCharacterSetTable(BufferedReader in) throws IOException {
152 String line;
153 while ((line = in.readLine()) != null) {
154 addEntry(parseCharSetEntry(line));
155 }
156 }
157
158
161 private void parseCharacterSetTable() {
162 ClassLoader loader = Encodings.class.getClassLoader();
163 if (loader == null) {
164 loader = ClassLoader.getSystemClassLoader();
166 }
167 InputStream inStream = loader.getResourceAsStream(CHAR_SET_TABLE);
168 if (inStream == null) {
169 throw new XMLIOError("can't find \"" + CHAR_SET_TABLE + "\" on class path");
170 }
171 try {
172 try {
173 BufferedReader in = new BufferedReader (new InputStreamReader (inStream));
174 parseCharacterSetTable(in);
175 } finally {
176 inStream.close();
177 }
178 } catch (IOException except) {
179 throw new XMLIOError("error reading " + CHAR_SET_TABLE);
180 }
181 }
182
183
186 private Encodings() {
187 parseCharacterSetTable();
188 }
189
190
193 public CharacterSet getCharacterSet(String encoding) {
194 return (CharacterSet)fCharSets.get(encoding.toUpperCase());
195 }
196
197
200 public boolean isValid(String encoding) {
201 return getCharacterSet(encoding) != null;
202 }
203
204
208 public String getName(String encoding) {
209 CharacterSet charSet = getCharacterSet(encoding);
210 if (charSet == null) {
211 return null;
212 } else {
213 return charSet.getName();
214 }
215 }
216
217
220 public String getMIMEPreferred(String encoding) {
221 CharacterSet charSet = getCharacterSet(encoding);
222 if (charSet == null) {
223 return null;
224 } else {
225 return charSet.getMIMEPreferred();
226 }
227 }
228
229
233 public String [] getAliases(String encoding) {
234 CharacterSet charSet = getCharacterSet(encoding);
235 if (charSet == null) {
236 return null;
237 } else {
238 return charSet.getAliases();
239 }
240 }
241
242
247 public int getMaxCharacterValue(String encoding) {
248 CharacterSet charSet = getCharacterSet(encoding);
249 if (charSet == null) {
250 return 0xFFFF; } else {
252 return charSet.getMaxCharValue();
253 }
254 }
255
256
260 public boolean sameEncodings(String encoding1,
261 String encoding2) {
262 if ((encoding1 == null) && (encoding2 == null)) {
263 return true;
264 } else if ((encoding1 == null) || (encoding2 == null)) {
265 return false;
266 } else {
267 return (getCharacterSet(encoding1) == getCharacterSet(encoding2));
268 }
269 }
270
271
274 public String toString() {
275 StringBuffer buf = new StringBuffer (4096); Iterator values = fCharSets.values().iterator();
277 while (values.hasNext()) {
278 buf.append(values.next().toString());
279 buf.append('\n');
280 }
281 return buf.toString();
282 }
283
284
287 public static Encodings getEncodings() {
288 if (fSingleton == null) {
289 fSingleton = new Encodings();
290 }
291 return fSingleton;
292 }
293 }
294 |
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