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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 }