JavaLang


1   /*
2    * Enhydra Java Application Server Project
3    * 
4    * The contents of this file are subject to the Enhydra Public License
5    * Version 1.1 (the "License"); you may not use this file except in
6    * compliance with the License. You may obtain a copy of the License on
7    * the Enhydra web site ( http://www.enhydra.org/ ).
8    * 
9    * Software distributed under the License is distributed on an "AS IS"
10   * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See 
11   * the License for the specific terms governing rights and limitations
12   * under the License.
13   * 
14   * The Initial Developer of the Enhydra Application Server is Lutris
15   * Technologies, Inc. The Enhydra Application Server and portions created
16   * by Lutris Technologies, Inc. are Copyright Lutris Technologies, Inc.
17   * All Rights Reserved.
18   * 
19   * Contributor(s):
20   * 
21   * $Id: JavaLang.java,v 1.2 2005/01/26 08:29:24 jkjome Exp $
22   */
23  
24  package org.enhydra.xml.xmlc.codegen;
25  
26  import java.io.File  ;
27  import java.util.StringTokenizer  ;
28  
29  /**
30   * Collection of methods and constants dealing with the Java language.
31   */
32  public final class JavaLang {
33      /** 
34       * Indentation amount, as a string of blanks.
35       */
36      public static final String   INDENT_STR = "    ";
37  
38      /**
39       * Line seperator to use on this platform
40       */
41      public static final char lineSeparator;
42  
43      /*
44       * Class initializer.
45       */
46      static {
47          String   lineSepStr = System.getProperty("line.separator");
48          lineSeparator = ((lineSepStr != null) && (lineSepStr.length() > 0))
49              ? lineSepStr.charAt(0) : '\n';
50      }
51      
52      /**
53       * Prevent instanciation.
54       */
55      private JavaLang() {
56      }
57  
58      /*
59       * Parse a class or package name.
60       */
61      public static String  [] parseClassName(String   name) {
62          StringTokenizer   tokens = new StringTokenizer  (name, ".");
63          String  [] names = new String  [tokens.countTokens()];
64  
65          for (int i = 0; i < names.length; i++) {
66              names[i] = tokens.nextToken();
67          }
68          return names;
69      }
70  
71      /*
72       * Get the class name without the package.
73       * @param obj Any object or class object.
74       */
75      public static String   simpleClassName(Object   obj) {
76          if (obj instanceof Class  ) {
77              return simpleClassName(((Class  )obj).getName());
78          } else {
79              return simpleClassName(obj.getClass().getName());
80          }
81      }
82  
83      /*
84       * Get the class name without the package.
85       */
86      public static String   simpleClassName(String   className) {
87          int lastDot = className.lastIndexOf('.');
88          if (lastDot < 0) {
89              return className;
90          } else {
91              return className.substring(lastDot+1);
92          }
93      }
94  
95      /*
96       * Get the package name of a class, or null if the default
97       * package is used.
98       */
99      public static String   getPackageName(String   className) {
100         int lastDot = className.lastIndexOf('.');
101         if (lastDot < 0) {
102             return "";
103         } else {
104             return className.substring(0, lastDot);
105         }
106     }
107 
108     /**
109      * Convert a package name to a relative platform file name.
110      */
111     public static String   packageNameToFileName(String   packageName) {
112         return packageName.replace('.', File.separatorChar);
113     }
114 
115     /**
116      * Convert a package name to a relative Unix file name.
117      */
118     public static String   packageNameToUnixFileName(String   packageName) {
119         return packageName.replace('.', '/');
120     }
121 
122     /**
123      * Convert a unicode character to its \\uXXXX representation
124      * and append to a buffer.
125      */
126     private static void toUnicodeEncoding(char ch, StringBuffer   buf) {
127         String   numStr = Integer.toHexString(ch);
128         buf.append("\\u");
129         for (int cnt = 4-numStr.length(); cnt > 0; cnt--) {
130             buf.append('0');
131         }
132         buf.append(numStr);
133     }
134 
135     /**
136      * Generate a Java string constant, quoting `\' and `"' and converting
137      * newlines.
138      *
139      * @param text Text to quote.
140      * @return The quoted string.
141      */
142     public static String   createStringConst(String   text) {
143         if (text == null) {
144             return "null";
145         }
146 
147         StringBuffer   str = new StringBuffer  ();
148         int len = text.length ();
149 
150         str.append ("\"");
151         for (int idx = 0; idx < len; idx++) {
152             char textChar = text.charAt (idx);
153             switch (textChar) {
154             case '\\':
155             case '"':
156                 str.append ('\\');
157                 str.append (textChar);
158                 break;
159             case '\t':
160                 str.append ("\\t");
161                 break;
162             case '\n':
163                 str.append ("\\n");
164                 break;
165             case '\r':
166                 str.append ("\\r");
167                 break;
168             default:
169                 if ((textChar > 127) || (Character.isISOControl(textChar))) {
170                     toUnicodeEncoding(textChar, str);
171                 } else {
172                     str.append (textChar);
173                 }
174                 break;
175             }
176         }
177         str.append ("\"");
178         return str.toString();
179     }
180 
181     /*
182      * Determine if a string is a legal Java identifier
183      */
184     public static boolean legalJavaIdentifier(String   str) {
185         if (str.length() == 0) {
186             return false;
187         }
188         if (!Character.isJavaIdentifierStart(str.charAt(0))) {
189             return false;
190         }
191         for (int j = 1; j < str.length(); j++) {
192             if (!Character.isJavaIdentifierPart(str.charAt(j))) {
193                 return false;
194             }
195         }
196         return true;
197     }
198 
199     /**
200      * Construct a white-space string of a given length to use
201      * for indentation.
202      */
203     public static String   makeIndent(int len) {
204         StringBuffer   prefix = new StringBuffer  ();
205         for (int idx = 0; idx < len; idx++) {
206             prefix.append(' ');
207         }
208         return prefix.toString();
209     }
210 
211 }
212
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