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Java > Open Source Codes > org > netbeans > modules > lexer > gen > util > LexerGenUtilitiesImpl


1 /*
2  * The contents of this file are subject to the terms of the Common Development
3  * and Distribution License (the License). You may not use this file except in
4  * compliance with the License.
5  *
6  * You can obtain a copy of the License at http://www.netbeans.org/cddl.html
7  * or http://www.netbeans.org/cddl.txt.
8  *
9  * When distributing Covered Code, include this CDDL Header Notice in each file
10  * and include the License file at http://www.netbeans.org/cddl.txt.
11  * If applicable, add the following below the CDDL Header, with the fields
12  * enclosed by brackets [] replaced by your own identifying information:
13  * "Portions Copyrighted [year] [name of copyright owner]"
14  *
15  * The Original Software is NetBeans. The Initial Developer of the Original
16  * Software is Sun Microsystems, Inc. Portions Copyright 1997-2007 Sun
17  * Microsystems, Inc. All Rights Reserved.
18  */
19
20 package org.netbeans.modules.lexer.gen.util;
21
22 /**
23  * Implementation of some lengthy methods in LexerUtil.
24  *
25  * @author Miloslav Metelka
26  * @version 1.00
27  */
28
29 class LexerGenUtilitiesImpl {
30
31     private static final char[] HEX_DIGIT = {'0','1','2','3','4','5','6','7',
32          '8','9','A','B','C','D','E','F'};
33
34
35     /** Convert string from the shape as it appears
36      * in the source file into regular java string.
37      */
38     public static String JavaDoc fromSource(String JavaDoc s) {
39         StringBuffer JavaDoc sb = new StringBuffer JavaDoc();
40
41         int len = s.length();
42         for (int i = 0; i < len; i++) {
43             char ch = s.charAt(i);
44             if (ch == '\\') {
45                 if (++i >= len) {
46                     throwIAE(s);
47                 }
48                 
49                 ch = s.charAt(i);
50                 switch (ch) {
51                     case 'n':
52                         ch = '\n';
53                         break;
54
55                     case 'r':
56                         ch = '\r';
57                         break;
58
59                     case 't':
60                         ch = '\t';
61                         break;
62
63                     case 'b':
64                         ch = '\b';
65                         break;
66
67                     case 'f':
68                         ch = '\f';
69                         break;
70                         
71                     case 'u':
72                         int uEnd = ++i + 4;
73                         if (uEnd > len) {
74                             throwIAE(s);
75                         }
76                         
77                         int val = 0;
78                         while (i < uEnd) {
79                             ch = s.charAt(i++);
80                             if (ch >= '0' && ch <= '9') {
81                                 val = (val << 4) + ch - '0';
82                                 
83                             } else {
84                                 ch = Character.toLowerCase(ch);
85                                 if (ch >= 'a' && ch <= 'f') {
86                                     val = (val << 4) + 10 + ch - 'a';
87                                     
88                                 } else {
89                                     throw new IllegalArgumentException JavaDoc(
90                                         "Malformed \\uxxxx encoding in string='"
91                                         + s + "'");
92                                 }
93                             }
94                         }
95                         ch = (char)val;
96                         break;
97                         
98                     default:
99                         // Convert octal constants
100 if (ch >= '0' && ch <= '7') {
101                             val = ch - '0';
102                             int maxDigCnt = (val < 4) ? 2 : 1;
103                             while (maxDigCnt-- > 0) {
104                                 ch = s.charAt(++i);
105                                 if (ch < '0' || ch > '7') {
106                                     i--;
107                                     break;
108                                 }
109                                 val = (val << 3) + (val - '0');
110                             }
111                             ch = (char)val;
112                         }
113                 }
114             }
115             
116             sb.append(ch);
117         }
118         
119         return sb.toString();
120     }
121
122     private static void throwIAE(String JavaDoc s) {
123         throw new IllegalArgumentException JavaDoc("Unexpected end of string s='" + s + "'");
124     }
125
126     static String JavaDoc toElementContent(String JavaDoc text) {
127         if (text == null) {
128             throw new NullPointerException JavaDoc();
129         }
130         
131         if (checkContentCharacters(text)) return text;
132         
133         StringBuffer JavaDoc buf = new StringBuffer JavaDoc();
134                 
135         for (int i = 0; i<text.length(); i++) {
136             char ch = text.charAt(i);
137             if ('<' == ch) {
138                 buf.append("&lt;");
139                 continue;
140             } else if ('&' == ch) {
141                 buf.append("&amp;");
142                 continue;
143             } else if ('>' == ch && i>1 && text.charAt(i-2) == ']' && text.charAt(i-1) == ']') {
144                 buf.append("&gt;");
145                 continue;
146             }
147             buf.append(ch);
148         }
149         return buf.toString();
150     }
151
152     /**
153      * Check if all passed characters match XML expression [2].
154      * @return true if no escaping necessary
155      * @throws IllegalArgumentException if contains invalid chars
156      */
157     private static boolean checkContentCharacters(String JavaDoc chars) {
158         boolean escape = false;
159         for (int i = 0; i<chars.length(); i++) {
160             char ch = chars.charAt(i);
161             if (((int)ch) <= 93) { // we are UNICODE ']'
162 switch (ch) {
163                     case 0x9:
164                     case 0xA:
165                     case 0xD:
166                         continue;
167                     case '>': // only ]]> is dangerous
168 if (escape) continue;
169                         escape = i > 0 && (chars.charAt(i - 1) == ']');
170                         continue;
171                     case '<':
172                     case '&':
173                         escape = true;
174                         continue;
175                     default:
176                         if (((int) ch) < 0x20) {
177                             throw new IllegalArgumentException JavaDoc(
178                                 "Invalid XML character &#" + ((int)ch) + ";.");
179                         }
180                 }
181             }
182         }
183         return escape == false;
184     }
185
186 }
187
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