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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *     http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  
18  package org.apache.commons.configuration;
19  
20  import java.io.BufferedReader;
21  import java.io.File;
22  import java.io.IOException;
23  import java.io.PrintWriter;
24  import java.io.Reader;
25  import java.io.Writer;
26  import java.net.URL;
27  import java.util.Collection;
28  import java.util.Iterator;
29  import java.util.Set;
30  import java.util.TreeSet;
31  
32  import org.apache.commons.lang.StringUtils;
33  
34  /***
35   * <p>
36   * An initialization or ini file is a configuration file tpically found on
37   * Microsoft's Windows operating system and contains data for Windows based
38   * applications.
39   * </p>
40   *
41   * <p>
42   * Although popularized by Windows, ini files can be used on any system or
43   * platform due to the fact that they are merely text files that can easily be
44   * parsed and modified by both humans and computers.
45   * </p>
46   *
47   * <p>
48   * A typcial ini file could look something like:
49   * </p>
50   * <code>
51   * [section1]<br>
52   * ; this is a comment!<br>
53   * var1 = foo<br>
54   * var2 = bar<br>
55   *<br>
56   * [section2]<br>
57   * var1 = doo<br>
58   * </code>
59   *
60   * <p>
61   * The format of ini files is fairly straight forward and is composed of three
62   * components:<br>
63   * <ul>
64   * <li><b>Sections:</b> Ini files are split into sections, each section
65   * starting with a section declaration. A section declaration starts with a '['
66   * and ends with a ']'. Sections occur on one line only.</li>
67   * <li><b>Parameters:</b> Items in a section are known as parameters.
68   * Parameters have a typical <code>key = value</code> format.</li>
69   * <li><b>Comments:</b> Lines starting with a ';' are assumed to be comments.
70   * </li>
71   * </ul>
72   * </p>
73   *
74   * <p>
75   * There are various implementations of the ini file format by various vendors
76   * which has caused a number of differences to appear. As far as possible this
77   * configuration tries to be lenient and support most of the differences.
78   * </p>
79   *
80   * <p>
81   * Some of the differences supported are as follows:
82   * <ul>
83   * <li><b>Comments:</b> The '#' character is also accepted as a comment
84   * signifier.</li>
85   * <li><b>Key value separtor:</b> The ':' character is also accepted in place
86   * of '=' to separate keys and values in parameters, for example
87   * <code>var1 : foo</code>.</li>
88   * <li><b>Duplicate sections:</b> Typically duplicate sections are not allowed ,
89   * this configuration does however support it. In the event of a duplicate
90   * section, the two section's values are merged.</li>
91   * <li><b>Duplicate parameters:</b> Typically duplicate parameters are only
92   * allowed if they are in two different sections, thus they are local to
93   * sections; this configuration simply merges duplicates; if a section has a
94   * duplicate parameter the values are then added to the key as a list. </li>
95   * </ul>
96   * </p>
97   * <p>
98   * Global parameters are also allowed; any parameters declared before a section
99   * is declared are added to a global section. It is important to note that this
100  * global section does not have a name.
101  * </p>
102  * <p>
103  * In all instances, a parameter's key is prepended with its section name and a
104  * '.' (period). Thus a parameter named "var1" in "section1" will have the key
105  * <code>section1.var1</code> in this configuration. Thus, a section's
106  * parameters can easily be retrieved using the <code>subset</code> method
107  * using the section name as the prefix.
108  * </p>
109  * <p>
110  * <h3>Implementation Details:</h3>
111  * Consider the following ini file:<br>
112  * <code>
113  *  default = ok<br>
114  *  <br>
115  *  [section1]<br>
116  *  var1 = foo<br>
117  *  var2 = doodle<br>
118  *   <br>
119  *  [section2]<br>
120  *  ; a comment<br>
121  *  var1 = baz<br>
122  *  var2 = shoodle<br>
123  *  bad =<br>
124  *  = worse<br>
125  *  <br>
126  *  [section3]<br>
127  *  # another comment<br>
128  *  var1 : foo<br>
129  *  var2 : bar<br>
130  *  var5 : test1<br>
131  *  <br>
132  *  [section3]<br>
133  *  var3 = foo<br>
134  *  var4 = bar<br>
135  *  var5 = test2<br>
136  *  </code>
137  * </p>
138  * <p>
139  * This ini file will be parsed without error. Note:
140  * <ul>
141  * <li>The parameter named "default" is added to the global section, it's value
142  * is accessed simply using <code>getProperty("default")</code>.</li>
143  * <li>Section 1's parameters can be accessed using
144  * <code>getProperty("section1.var1")</code>.</li>
145  * <li>The parameter named "bad" simply adds the parameter with an empty value.
146  * </li>
147  * <li>The empty key with value "= worse" is added using an empty key. This key
148  * is still added to section 2 and the value can be accessed using
149  * <code>getProperty("section2.")</code>, notice the period '.' following the
150  * section name.</li>
151  * <li>Section three uses both '=' and ':' to separate keys and values.</li>
152  * <li>Section 3 has a duplicate key named "var5". The value for this key is
153  * [test1, test2], and is represented as a List.</li>
154  * </ul>
155  * </p>
156  * <p>
157  * The set of sections in this configuration can be retrieved using the
158  * <code>getSections</code> method.
159  * </p>
160  * <p>
161  * <em>Note:</em>Configuration objects of this type can be read concurrently
162  * by multiple threads. However if one of these threads modifies the object,
163  * synchronization has to be performed manually.
164  * </p>
165  *
166  * @author Trevor Miller
167  * @version $Id: INIConfiguration.java 589380 2007-10-28 16:37:35Z oheger $
168  * @since 1.4
169  */
170 public class INIConfiguration extends AbstractFileConfiguration
171 {
172     /***
173      * The characters that signal the start of a comment line.
174      */
175     protected static final String COMMENT_CHARS = "#;";
176 
177     /***
178      * The characters used to separate keys from values.
179      */
180     protected static final String SEPARATOR_CHARS = "=:";
181 
182     /***
183      * Create a new empty INI Configuration.
184      */
185     public INIConfiguration()
186     {
187         super();
188     }
189 
190     /***
191      * Create and load the ini configuration from the given file.
192      *
193      * @param filename The name pr path of the ini file to load.
194      * @throws ConfigurationException If an error occurs while loading the file
195      */
196     public INIConfiguration(String filename) throws ConfigurationException
197     {
198         super(filename);
199     }
200 
201     /***
202      * Create and load the ini configuration from the given file.
203      *
204      * @param file The ini file to load.
205      * @throws ConfigurationException If an error occurs while loading the file
206      */
207     public INIConfiguration(File file) throws ConfigurationException
208     {
209         super(file);
210     }
211 
212     /***
213      * Create and load the ini configuration from the given url.
214      *
215      * @param url The url of the ini file to load.
216      * @throws ConfigurationException If an error occurs while loading the file
217      */
218     public INIConfiguration(URL url) throws ConfigurationException
219     {
220         super(url);
221     }
222 
223     /***
224      * Save the configuration to the specified writer.
225      *
226      * @param writer - The writer to save the configuration to.
227      * @throws ConfigurationException If an error occurs while writing the
228      * configuration
229      */
230     public void save(Writer writer) throws ConfigurationException
231     {
232         PrintWriter out = new PrintWriter(writer);
233         Iterator it = getSections().iterator();
234         while (it.hasNext())
235         {
236             String section = (String) it.next();
237             out.print("[");
238             out.print(section);
239             out.print("]");
240             out.println();
241 
242             Configuration subset = subset(section);
243             Iterator keys = subset.getKeys();
244             while (keys.hasNext())
245             {
246                 String key = (String) keys.next();
247                 Object value = subset.getProperty(key);
248                 if (value instanceof Collection)
249                 {
250                     Iterator values = ((Collection) value).iterator();
251                     while (values.hasNext())
252                     {
253                         value = (Object) values.next();
254                         out.print(key);
255                         out.print(" = ");
256                         out.print(formatValue(value.toString()));
257                         out.println();
258                     }
259                 }
260                 else
261                 {
262                     out.print(key);
263                     out.print(" = ");
264                     out.print(formatValue(value.toString()));
265                     out.println();
266                 }
267             }
268 
269             out.println();
270         }
271 
272         out.flush();
273     }
274 
275     /***
276      * Load the configuration from the given reader. Note that the
277      * <code>clear</code> method is not called so the configuration read in
278      * will be merged with the current configuration.
279      *
280      * @param reader The reader to read the configuration from.
281      * @throws ConfigurationException If an error occurs while reading the
282      * configuration
283      */
284     public void load(Reader reader) throws ConfigurationException
285     {
286         try
287         {
288             BufferedReader bufferedReader = new BufferedReader(reader);
289             String line = bufferedReader.readLine();
290             String section = "";
291             while (line != null)
292             {
293                 line = line.trim();
294                 if (!isCommentLine(line))
295                 {
296                     if (isSectionLine(line))
297                     {
298                         section = line.substring(1, line.length() - 1) + ".";
299                     }
300                     else
301                     {
302                         String key = "";
303                         String value = "";
304                         int index = line.indexOf("=");
305                         if (index >= 0)
306                         {
307                             key = section + line.substring(0, index);
308                             value = parseValue(line.substring(index + 1));
309                         }
310                         else
311                         {
312                             index = line.indexOf(":");
313                             if (index >= 0)
314                             {
315                                 key = section + line.substring(0, index);
316                                 value = parseValue(line.substring(index + 1));
317                             }
318                             else
319                             {
320                                 key = section + line;
321                             }
322                         }
323                         addProperty(key.trim(), value);
324                     }
325                 }
326                 line = bufferedReader.readLine();
327             }
328         }
329         catch (IOException ioe)
330         {
331             throw new ConfigurationException(ioe.getMessage());
332         }
333     }
334 
335     /***
336      * Parse the value to remove the quotes and ignoring the comment.
337      * Example:
338      *
339      * <pre>"value" ; comment -> value</pre>
340      *
341      * <pre>'value' ; comment -> value</pre>
342      *
343      * @param value
344      */
345     private String parseValue(String value)
346     {
347         value = value.trim();
348 
349         boolean quoted = value.startsWith("\"") || value.startsWith("'");
350         boolean stop = false;
351         boolean escape = false;
352 
353         char quote = quoted ? value.charAt(0) : 0;
354 
355         int i = quoted ? 1 : 0;
356 
357         StringBuffer result = new StringBuffer();
358         while (i < value.length() && !stop)
359         {
360             char c = value.charAt(i);
361 
362             if (quoted)
363             {
364                 if ('//' == c && !escape)
365                 {
366                     escape = true;
367                 }
368                 else if (!escape && quote == c)
369                 {
370                     stop = true;
371                 }
372                 else if (escape && quote == c)
373                 {
374                     escape = false;
375                     result.append(c);
376                 }
377                 else
378                 {
379                     if (escape)
380                     {
381                         escape = false;
382                         result.append('//');
383                     }
384 
385                     result.append(c);
386                 }
387             }
388             else
389             {
390                 if (COMMENT_CHARS.indexOf(c) == -1)
391                 {
392                     result.append(c);
393                 }
394                 else
395                 {
396                     stop = true;
397                 }
398             }
399 
400             i++;
401         }
402 
403         return result.toString().trim();
404     }
405 
406     /***
407      * Add quotes around the specified value if it contains a comment character.
408      */
409     private String formatValue(String value)
410     {
411         boolean quoted = false;
412 
413         for (int i = 0; i < COMMENT_CHARS.length() && !quoted; i++)
414         {
415             char c = COMMENT_CHARS.charAt(i);
416             if (value.indexOf(c) != -1)
417             {
418                 quoted = true;
419             }
420         }
421 
422         if (quoted)
423         {
424             return '"' + StringUtils.replace(value, "\"", "//\"") + '"';
425         }
426         else
427         {
428             return value;
429         }
430     }
431 
432     /***
433      * Determine if the given line is a comment line.
434      *
435      * @param line The line to check.
436      * @return true if the line is empty or starts with one of the comment
437      * characters
438      */
439     protected boolean isCommentLine(String line)
440     {
441         if (line == null)
442         {
443             return false;
444         }
445         // blank lines are also treated as comment lines
446         return line.length() < 1 || COMMENT_CHARS.indexOf(line.charAt(0)) >= 0;
447     }
448 
449     /***
450      * Determine if the given line is a section.
451      *
452      * @param line The line to check.
453      * @return true if the line contains a secion
454      */
455     protected boolean isSectionLine(String line)
456     {
457         if (line == null)
458         {
459             return false;
460         }
461         return line.startsWith("[") && line.endsWith("]");
462     }
463 
464     /***
465      * Return a set containing the sections in this ini configuration. Note that
466      * changes to this set do not affect the configuration.
467      *
468      * @return a set containing the sections.
469      */
470     public Set getSections()
471     {
472         Set sections = new TreeSet();
473 
474         Iterator keys = getKeys();
475         while (keys.hasNext())
476         {
477             String key = (String) keys.next();
478             int index = key.indexOf(".");
479             if (index >= 0)
480             {
481                 sections.add(key.substring(0, index));
482             }
483         }
484 
485         return sections;
486     }
487 }