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1
21 package org.lobobrowser.util;
22
23 import java.io.*;
24 import java.security.*;
25 import java.util.ArrayList  ;
26
27
30 public class Strings
31 {
32 private static final MessageDigest MESSAGE_DIGEST;
33 public static final String [] EMPTY_ARRAY = new String [0];
34
35 static {
36 MessageDigest md;
37 try {
38 md = MessageDigest.getInstance("MD5");
39 } catch(NoSuchAlgorithmException err) {
40 throw new IllegalStateException ();
41 }
42 MESSAGE_DIGEST = md;
43 }
44
45 private Strings() {}
46
47 public static int compareVersions(String version1, String version2) {
48 return version1.compareTo(version2);
49 }
50
51 public static boolean isBlank(String text) {
52 return text == null || "".equals(text);
53 }
54
55 public static int countLines(String text)
56 {
57 int startIdx = 0;
58 int lineCount = 1;
59 for(;;)
60 {
61 int lbIdx = text.indexOf('\n', startIdx);
62 if(lbIdx == -1)
63 {
64 break;
65 }
66 lineCount++;
67 startIdx = lbIdx + 1;
68 }
69 return lineCount;
70 }
71
72 public static boolean isJavaIdentifier(String id)
73 {
74 if(id == null)
75 {
76 return false;
77 }
78 int len = id.length();
79 if(len == 0)
80 {
81 return false;
82 }
83 if(!Character.isJavaIdentifierStart(id.charAt(0)))
84 {
85 return false;
86 }
87 for(int i = 1; i < len; i++)
88 {
89 if(!Character.isJavaIdentifierPart(id.charAt(i)))
90 {
91 return false;
92 }
93 }
94 return true;
95 }
96
97 public static String getTextFromStream(InputStream in) throws IOException {
98 Reader reader = new InputStreamReader(in, "UTF-8");
99 char[] buffer = new char[256];
100 int numRead;
101 int offset = 0;
102 while((numRead = reader.read(buffer, offset, buffer.length - offset)) != -1) {
103 offset += numRead;
104 if(offset >= (buffer.length * 2) / 3) {
105 char[] newBuffer = new char[buffer.length * 2];
106 System.arraycopy(buffer, 0, newBuffer, 0, offset);
107 buffer = newBuffer;
108 }
109 }
110 return new String (buffer, 0, offset);
111 }
112
113 public static String getJavaStringLiteral(String text) {
114 StringBuffer buf = new StringBuffer ();
115 buf.append('"');
116 int len = text.length();
117 for(int i = 0; i < len; i++) {
118 char ch = text.charAt(i);
119 switch(ch) {
120 case '\\':
121 buf.append("\\\\");
122 break;
123 case '\n':
124 buf.append("\\n");
125 break;
126 case '\r':
127 buf.append("\\r");
128 break;
129 case '\t':
130 buf.append("\\t");
131 break;
132 case '"':
133 buf.append("\\\"");
134 break;
135 default:
136 buf.append(ch);
137 break;
138 }
139 }
140 buf.append('"');
141 return buf.toString();
142 }
143
144 public static String getJavaIdentifier(String candidateID) {
145 int len = candidateID.length();
146 StringBuffer buf = new StringBuffer ();
147 for(int i = 0; i < len; i++)
148 {
149 char ch = candidateID.charAt(i);
150 boolean good = i == 0 ? Character.isJavaIdentifierStart(ch) : Character.isJavaIdentifierPart(ch);
151 if(good)
152 {
153 buf.append(ch);
154 }
155 else {
156 buf.append('_');
157 }
158 }
159 return buf.toString();
160 }
161
162 private static final String HEX_CHARS = "0123456789ABCDEF";
163
164 public static String getMD5(String source) throws UnsupportedEncodingException {
165 byte[] bytes = source.getBytes("UTF8");
166 byte[] result;
167 synchronized(MESSAGE_DIGEST) {
168 MESSAGE_DIGEST.update(bytes);
169 result = MESSAGE_DIGEST.digest();
170 }
171 char[] resChars = new char[32];
172 int len = result.length;
173 for(int i = 0; i < len; i++) {
174 byte b = result[i];
175 int lo4 = b & 0x0F;
176 int hi4 = (b & 0xF0) >> 4;
177 resChars[i*2] = HEX_CHARS.charAt(hi4);
178 resChars[i*2 + 1] = HEX_CHARS.charAt(lo4);
179 }
180 return new String (resChars);
181 }
182
183 public static String getHash32(String source) throws UnsupportedEncodingException {
184 String md5 = getMD5(source);
185 return md5.substring(0, 8);
186 }
187
188 public static String getHash64(String source) throws UnsupportedEncodingException {
189 String md5 = getMD5(source);
190 return md5.substring(0, 16);
191 }
192
193 public static int countChars(String text, char ch) {
194 int len = text.length();
195 int count = 0;
196 for(int i = 0; i < len; i++) {
197 if(ch == text.charAt(i)) {
198 count++;
199 }
200 }
201 return count;
202 }
203
204
239 public static String unquote(String text) {
240 if(text.startsWith("\"") && text.endsWith("\"")) {
241 return text.substring(1, text.length() - 2);
242 }
243 return text;
244 }
245
246 public static String [] split(String phrase) {
247 int length = phrase.length();
248 ArrayList wordList = new ArrayList ();
249 StringBuffer word = null;
250 for(int i = 0; i < length; i++) {
251 char ch = phrase.charAt(i);
252 switch(ch) {
253 case ' ':
254 case '\t':
255 case '\r':
256 case '\n':
257 if(word != null) {
258 wordList.add(word.toString());
259 word = null;
260 }
261 break;
262 default:
263 if(word == null) {
264 word = new StringBuffer ();
265 }
266 word.append(ch);
267 }
268 }
269 if(word != null) {
270 wordList.add(word.toString());
271 }
272 return (String []) wordList.toArray(EMPTY_ARRAY);
273 }
274
275 public static String truncate(String text, int maxLength) {
276 if(text == null) {
277 return null;
278 }
279 if(text.length() <= maxLength) {
280 return text;
281 }
282 return text.substring(0, Math.max(maxLength - 3, 0)) + "...";
283 }
284
285 public static String strictHtmlEncode(String rawText) {
286 StringBuffer output = new StringBuffer ();
287 int length = rawText.length();
288 for(int i = 0; i < length; i++) {
289 char ch = rawText.charAt(i);
290 switch(ch) {
291 case '&':
292 output.append("&");
293 break;
294 case '"':
295 output.append(""");
296 break;
297 case '<':
298 output.append("<");
299 break;
300 case '>':
301 output.append(">");
302 break;
303 default:
304 output.append(ch);
305 }
306 }
307 return output.toString();
308 }
309
310 public static String trimForAlphaNumDash(String rawText) {
311 int length = rawText.length();
312 for(int i = 0; i < length; i++) {
313 char ch = rawText.charAt(i);
314 if((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z') || (ch >= '0' && ch <= '9') || ch == '-') {
315 continue;
316 }
317 return rawText.substring(0, i);
318 }
319 return rawText;
320 }
321 }
322 |
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