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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.File;
    21  import java.io.FilterWriter;
    22  import java.io.IOException;
    23  import java.io.LineNumberReader;
    24  import java.io.Reader;
    25  import java.io.Writer;
    26  import java.net.URL;
    27  import java.util.ArrayList;
    28  import java.util.Iterator;
    29  import java.util.List;
    30
    31  import org.apache.commons.lang.ArrayUtils;
    32  import org.apache.commons.lang.StringEscapeUtils;
    33  import org.apache.commons.lang.StringUtils;
    34
    35  /***
    36   * This is the "classic" Properties loader which loads the values from
    37   * a single or multiple files (which can be chained with "include =".
    38   * All given path references are either absolute or relative to the
    39   * file name supplied in the constructor.
    40   * <p>
    41   * In this class, empty PropertyConfigurations can be built, properties
    42   * added and later saved. include statements are (obviously) not supported
    43   * if you don't construct a PropertyConfiguration from a file.
    44   *
    45   * <p>The properties file syntax is explained here, basically it follows
    46   * the syntax of the stream parsed by {@link java.util.Properties#load} and
    47   * adds several useful extensions:
    48   *
    49   * <ul>
    50   *  <li>
    51   *   Each property has the syntax <code>key &lt;separator> value</code>. The
    52   *   separators accepted are <code>'='</code>, <code>':'</code> and any white
    53   *   space character. Examples:
    54   * <pre>
    55   *  key1 = value1
    56   *  key2 : value2
    57   *  key3   value3</pre>
    58   *  </li>
    59   *  <li>
    60   *   The <i>key</i> may use any character, separators must be escaped:
    61   * <pre>
    62   *  key\:foo = bar</pre>
    63   *  </li>
    64   *  <li>
    65   *   <i>value</i> may be separated on different lines if a backslash
    66   *   is placed at the end of the line that continues below.
    67   *  </li>
    68   *  <li>
    69   *   <i>value</i> can contain <em>value delimiters</em> and will then be interpreted
    70   *   as a list of tokens. Default value delimiter is the comma ','. So the
    71   *   following property definition
    72   * <pre>
    73   *  key = This property, has multiple, values
    74   * </pre>
    75   *   will result in a property with three values. You can change the value
    76   *   delimiter using the <code>{@link AbstractConfiguration#setListDelimiter(char)}</code>
    77   *   method. Setting the delimiter to 0 will disable value splitting completely.
    78   *  </li>
    79   *  <li>
    80   *   Commas in each token are escaped placing a backslash right before
    81   *   the comma.
    82   *  </li>
    83   *  <li>
    84   *   If a <i>key</i> is used more than once, the values are appended
    85   *   like if they were on the same line separated with commas. <em>Note</em>:
    86   *   When the configuration file is written back to disk the associated
    87   *   <code>{@link PropertiesConfigurationLayout}</code> object (see below) will
    88   *   try to preserve as much of the original format as possible, i.e. properties
    89   *   with multiple values defined on a single line will also be written back on
    90   *   a single line, and multiple occurrences of a single key will be written on
    91   *   multiple lines. If the <code>addProperty()</code> method was called
    92   *   multiple times for adding multiple values to a property, these properties
    93   *   will per default be written on multiple lines in the output file, too.
    94   *   Some options of the <code>PropertiesConfigurationLayout</code> class have
    95   *   influence on that behavior.
    96   *  </li>
    97   *  <li>
    98   *   Blank lines and lines starting with character '#' or '!' are skipped.
    99   *  </li>
    100  *  <li>
    101  *   If a property is named "include" (or whatever is defined by
    102  *   setInclude() and getInclude() and the value of that property is
    103  *   the full path to a file on disk, that file will be included into
    104  *   the configuration. You can also pull in files relative to the parent
    105  *   configuration file. So if you have something like the following:
    106  *
    107  *   include = additional.properties
    108  *
    109  *   Then "additional.properties" is expected to be in the same
    110  *   directory as the parent configuration file.
    111  *
    112  *   The properties in the included file are added to the parent configuration,
    113  *   they do not replace existing properties with the same key.
    114  *
    115  *  </li>
    116  * </ul>
    117  *
    118  * <p>Here is an example of a valid extended properties file:
    119  *
    120  * <p><pre>
    121  *      # lines starting with # are comments
    122  *
    123  *      # This is the simplest property
    124  *      key = value
    125  *
    126  *      # A long property may be separated on multiple lines
    127  *      longvalue = aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa \
    128  *                  aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
    129  *
    130  *      # This is a property with many tokens
    131  *      tokens_on_a_line = first token, second token
    132  *
    133  *      # This sequence generates exactly the same result
    134  *      tokens_on_multiple_lines = first token
    135  *      tokens_on_multiple_lines = second token
    136  *
    137  *      # commas may be escaped in tokens
    138  *      commas.escaped = Hi\, what'up?
    139  *
    140  *      # properties can reference other properties
    141  *      base.prop = /base
    142  *      first.prop = ${base.prop}/first
    143  *      second.prop = ${first.prop}/second
    144  * </pre>
    145  *
    146  * <p>A <code>PropertiesConfiguration</code> object is associated with an
    147  * instance of the <code>{@link PropertiesConfigurationLayout}</code> class,
    148  * which is responsible for storing the layout of the parsed properties file
    149  * (i.e. empty lines, comments, and such things). The <code>getLayout()</code>
    150  * method can be used to obtain this layout object. With <code>setLayout()</code>
    151  * a new layout object can be set. This should be done before a properties file
    152  * was loaded.
    153  * <p><em>Note:</em>Configuration objects of this type can be read concurrently
    154  * by multiple threads. However if one of these threads modifies the object,
    155  * synchronization has to be performed manually.
    156  *
    157  * @see java.util.Properties#load
    158  *
    159  * @author <a href="mailto:stefano@apache.org">Stefano Mazzocchi</a>
    160  * @author <a href="mailto:jon@latchkey.com">Jon S. Stevens</a>
    161  * @author <a href="mailto:daveb@miceda-data">Dave Bryson</a>
    162  * @author <a href="mailto:geirm@optonline.net">Geir Magnusson Jr.</a>
    163  * @author <a href="mailto:leon@opticode.co.za">Leon Messerschmidt</a>
    164  * @author <a href="mailto:kjohnson@transparent.com">Kent Johnson</a>
    165  * @author <a href="mailto:dlr@finemaltcoding.com">Daniel Rall</a>
    166  * @author <a href="mailto:ipriha@surfeu.fi">Ilkka Priha</a>
    167  * @author <a href="mailto:jvanzyl@apache.org">Jason van Zyl</a>
    168  * @author <a href="mailto:mpoeschl@marmot.at">Martin Poeschl</a>
    169  * @author <a href="mailto:hps@intermeta.de">Henning P. Schmiedehausen</a>
    170  * @author <a href="mailto:epugh@upstate.com">Eric Pugh</a>
    171  * @author Oliver Heger
    172  * @author <a href="mailto:ebourg@apache.org">Emmanuel Bourg</a>
    173  * @version $Id: PropertiesConfiguration.java 550047 2007-06-23 14:44:15Z oheger $
    174  */
    175 public class PropertiesConfiguration extends AbstractFileConfiguration
    176 {
    177     /*** Constant for the supported comment characters.*/
    178     static final String COMMENT_CHARS = "#!";
    179
    180     /***
    181      * This is the name of the property that can point to other
    182      * properties file for including other properties files.
    183      */
    184     private static String include = "include";
    185
    186     /*** The list of possible key/value separators */
    187     private static final char[] SEPARATORS = new char[] {'=', ':'};
    188
    189     /*** The white space characters used as key/value separators. */
    190     private static final char[] WHITE_SPACE = new char[]{' ', '\t', '\f'};
    191
    192     /***
    193      * The default encoding (ISO-8859-1 as specified by
    194      * http://java.sun.com/j2se/1.5.0/docs/api/java/util/Properties.html)
    195      */
    196     private static final String DEFAULT_ENCODING = "ISO-8859-1";
    197
    198     /*** Constant for the platform specific line separator.*/
    199     private static final String LINE_SEPARATOR = System.getProperty("line.separator");
    200
    201     /*** Constant for the escaping character.*/
    202     private static final String ESCAPE = "//";
    203
    204     /*** Constant for the radix of hex numbers.*/
    205     private static final int HEX_RADIX = 16;
    206
    207     /*** Constant for the length of a unicode literal.*/
    208     private static final int UNICODE_LEN = 4;
    209
    210     /*** Stores the layout object.*/
    211     private PropertiesConfigurationLayout layout;
    212
    213     /*** Allow file inclusion or not */
    214     private boolean includesAllowed;
    215
    216     // initialization block to set the encoding before loading the file in the constructors
    217     {
    218         setEncoding(DEFAULT_ENCODING);
    219     }
    220
    221     /***
    222      * Creates an empty PropertyConfiguration object which can be
    223      * used to synthesize a new Properties file by adding values and
    224      * then saving().
    225      */
    226     public PropertiesConfiguration()
    227     {
    228         layout = createLayout();
    229         setIncludesAllowed(false);
    230     }
    231
    232     /***
    233      * Creates and loads the extended properties from the specified file.
    234      * The specified file can contain "include = " properties which then
    235      * are loaded and merged into the properties.
    236      *
    237      * @param fileName The name of the properties file to load.
    238      * @throws ConfigurationException Error while loading the properties file
    239      */
    240     public PropertiesConfiguration(String fileName) throws ConfigurationException
    241     {
    242         super(fileName);
    243     }
    244
    245     /***
    246      * Creates and loads the extended properties from the specified file.
    247      * The specified file can contain "include = " properties which then
    248      * are loaded and merged into the properties. If the file does not exist,
    249      * an empty configuration will be created. Later the <code>save()</code>
    250      * method can be called to save the properties to the specified file.
    251      *
    252      * @param file The properties file to load.
    253      * @throws ConfigurationException Error while loading the properties file
    254      */
    255     public PropertiesConfiguration(File file) throws ConfigurationException
    256     {
    257         super(file);
    258
    259         // If the file does not exist, no layout object was created. We have to
    260         // do this manually in this case.
    261         if (layout == null)
    262         {
    263             layout = createLayout();
    264         }
    265     }
    266
    267     /***
    268      * Creates and loads the extended properties from the specified URL.
    269      * The specified file can contain "include = " properties which then
    270      * are loaded and merged into the properties.
    271      *
    272      * @param url The location of the properties file to load.
    273      * @throws ConfigurationException Error while loading the properties file
    274      */
    275     public PropertiesConfiguration(URL url) throws ConfigurationException
    276     {
    277         super(url);
    278     }
    279
    280     /***
    281      * Gets the property value for including other properties files.
    282      * By default it is "include".
    283      *
    284      * @return A String.
    285      */
    286     public static String getInclude()
    287     {
    288         return PropertiesConfiguration.include;
    289     }
    290
    291     /***
    292      * Sets the property value for including other properties files.
    293      * By default it is "include".
    294      *
    295      * @param inc A String.
    296      */
    297     public static void setInclude(String inc)
    298     {
    299         PropertiesConfiguration.include = inc;
    300     }
    301
    302     /***
    303      * Controls whether additional files can be loaded by the include = <xxx>
    304      * statement or not. Base rule is, that objects created by the empty
    305      * C'tor can not have included files.
    306      *
    307      * @param includesAllowed includesAllowed True if Includes are allowed.
    308      */
    309     protected void setIncludesAllowed(boolean includesAllowed)
    310     {
    311         this.includesAllowed = includesAllowed;
    312     }
    313
    314     /***
    315      * Reports the status of file inclusion.
    316      *
    317      * @return True if include files are loaded.
    318      */
    319     public boolean getIncludesAllowed()
    320     {
    321         return this.includesAllowed;
    322     }
    323
    324     /***
    325      * Return the comment header.
    326      *
    327      * @return the comment header
    328      * @since 1.1
    329      */
    330     public String getHeader()
    331     {
    332         return getLayout().getHeaderComment();
    333     }
    334
    335     /***
    336      * Set the comment header.
    337      *
    338      * @param header the header to use
    339      * @since 1.1
    340      */
    341     public void setHeader(String header)
    342     {
    343         getLayout().setHeaderComment(header);
    344     }
    345
    346     /***
    347      * Returns the associated layout object.
    348      *
    349      * @return the associated layout object
    350      * @since 1.3
    351      */
    352     public synchronized PropertiesConfigurationLayout getLayout()
    353     {
    354         if (layout == null)
    355         {
    356             layout = createLayout();
    357         }
    358         return layout;
    359     }
    360
    361     /***
    362      * Sets the associated layout object.
    363      *
    364      * @param layout the new layout object; can be <b>null</b>, then a new
    365      * layout object will be created
    366      * @since 1.3
    367      */
    368     public synchronized void setLayout(PropertiesConfigurationLayout layout)
    369     {
    370         // only one layout must exist
    371         if (this.layout != null)
    372         {
    373             removeConfigurationListener(this.layout);
    374         }
    375
    376         if (layout == null)
    377         {
    378             this.layout = createLayout();
    379         }
    380         else
    381         {
    382             this.layout = layout;
    383         }
    384     }
    385
    386     /***
    387      * Creates the associated layout object. This method is invoked when the
    388      * layout object is accessed and has not been created yet. Derived classes
    389      * can override this method to hook in a different layout implementation.
    390      *
    391      * @return the layout object to use
    392      * @since 1.3
    393      */
    394     protected PropertiesConfigurationLayout createLayout()
    395     {
    396         return new PropertiesConfigurationLayout(this);
    397     }
    398
    399     /***
    400      * Load the properties from the given reader.
    401      * Note that the <code>clear()</code> method is not called, so
    402      * the properties contained in the loaded file will be added to the
    403      * actual set of properties.
    404      *
    405      * @param in An InputStream.
    406      *
    407      * @throws ConfigurationException if an error occurs
    408      */
    409     public synchronized void load(Reader in) throws ConfigurationException
    410     {
    411         boolean oldAutoSave = isAutoSave();
    412         setAutoSave(false);
    413
    414         try
    415         {
    416             getLayout().load(in);
    417         }
    418         finally
    419         {
    420             setAutoSave(oldAutoSave);
    421         }
    422     }
    423
    424     /***
    425      * Save the configuration to the specified stream.
    426      *
    427      * @param writer the output stream used to save the configuration
    428      * @throws ConfigurationException if an error occurs
    429      */
    430     public void save(Writer writer) throws ConfigurationException
    431     {
    432         enterNoReload();
    433         try
    434         {
    435             getLayout().save(writer);
    436         }
    437         finally
    438         {
    439             exitNoReload();
    440         }
    441     }
    442
    443     /***
    444      * Extend the setBasePath method to turn includes
    445      * on and off based on the existence of a base path.
    446      *
    447      * @param basePath The new basePath to set.
    448      */
    449     public void setBasePath(String basePath)
    450     {
    451         super.setBasePath(basePath);
    452         setIncludesAllowed(StringUtils.isNotEmpty(basePath));
    453     }
    454
    455     /***
    456      * Creates a copy of this object.
    457      *
    458      * @return the copy
    459      */
    460     public Object clone()
    461     {
    462         PropertiesConfiguration copy = (PropertiesConfiguration) super.clone();
    463         if (layout != null)
    464         {
    465             copy.setLayout(new PropertiesConfigurationLayout(copy, layout));
    466         }
    467         return copy;
    468     }
    469
    470     /***
    471      * This method is invoked by the associated
    472      * <code>{@link PropertiesConfigurationLayout}</code> object for each
    473      * property definition detected in the parsed properties file. Its task is
    474      * to check whether this is a special property definition (e.g. the
    475      * <code>include</code> property). If not, the property must be added to
    476      * this configuration. The return value indicates whether the property
    477      * should be treated as a normal property. If it is <b>false</b>, the
    478      * layout object will ignore this property.
    479      *
    480      * @param key the property key
    481      * @param value the property value
    482      * @return a flag whether this is a normal property
    483      * @throws ConfigurationException if an error occurs
    484      * @since 1.3
    485      */
    486     boolean propertyLoaded(String key, String value)
    487             throws ConfigurationException
    488     {
    489         boolean result;
    490
    491         if (StringUtils.isNotEmpty(getInclude())
    492                 && key.equalsIgnoreCase(getInclude()))
    493         {
    494             if (getIncludesAllowed())
    495             {
    496                 String[] files;
    497                 if (!isDelimiterParsingDisabled())
    498                 {
    499                     files = StringUtils.split(value, getListDelimiter());
    500                 }
    501                 else
    502                 {
    503                     files = new String[]{value};
    504                 }
    505                 for (int i = 0; i < files.length; i++)
    506                 {
    507                     loadIncludeFile(files[i].trim());
    508                 }
    509             }
    510             result = false;
    511         }
    512
    513         else
    514         {
    515             addProperty(key, value);
    516             result = true;
    517         }
    518
    519         return result;
    520     }
    521
    522     /***
    523      * Tests whether a line is a comment, i.e. whether it starts with a comment
    524      * character.
    525      *
    526      * @param line the line
    527      * @return a flag if this is a comment line
    528      * @since 1.3
    529      */
    530     static boolean isCommentLine(String line)
    531     {
    532         String s = line.trim();
    533         // blanc lines are also treated as comment lines
    534         return s.length() < 1 || COMMENT_CHARS.indexOf(s.charAt(0)) >= 0;
    535     }
    536
    537     /***
    538      * This class is used to read properties lines. These lines do
    539      * not terminate with new-line chars but rather when there is no
    540      * backslash sign a the end of the line.  This is used to
    541      * concatenate multiple lines for readability.
    542      */
    543     public static class PropertiesReader extends LineNumberReader
    544     {
    545         /*** Stores the comment lines for the currently processed property.*/
    546         private List commentLines;
    547
    548         /*** Stores the name of the last read property.*/
    549         private String propertyName;
    550
    551         /*** Stores the value of the last read property.*/
    552         private String propertyValue;
    553
    554         /*** Stores the list delimiter character.*/
    555         private char delimiter;
    556
    557         /***
    558          * Constructor.
    559          *
    560          * @param reader A Reader.
    561          */
    562         public PropertiesReader(Reader reader)
    563         {
    564             this(reader, AbstractConfiguration.getDefaultListDelimiter());
    565         }
    566
    567         /***
    568          * Creates a new instance of <code>PropertiesReader</code> and sets
    569          * the underlaying reader and the list delimiter.
    570          *
    571          * @param reader the reader
    572          * @param listDelimiter the list delimiter character
    573          * @since 1.3
    574          */
    575         public PropertiesReader(Reader reader, char listDelimiter)
    576         {
    577             super(reader);
    578             commentLines = new ArrayList();
    579             delimiter = listDelimiter;
    580         }
    581
    582         /***
    583          * Reads a property line. Returns null if Stream is
    584          * at EOF. Concatenates lines ending with "\".
    585          * Skips lines beginning with "#" or "!" and empty lines.
    586          * The return value is a property definition (<code>&lt;name&gt;</code>
    587          * = <code>&lt;value&gt;</code>)
    588          *
    589          * @return A string containing a property value or null
    590          *
    591          * @throws IOException in case of an I/O error
    592          */
    593         public String readProperty() throws IOException
    594         {
    595             commentLines.clear();
    596             StringBuffer buffer = new StringBuffer();
    597
    598             while (true)
    599             {
    600                 String line = readLine();
    601                 if (line == null)
    602                 {
    603                     // EOF
    604                     return null;
    605                 }
    606
    607                 if (isCommentLine(line))
    608                 {
    609                     commentLines.add(line);
    610                     continue;
    611                 }
    612
    613                 line = line.trim();
    614
    615                 if (checkCombineLines(line))
    616                 {
    617                     line = line.substring(0, line.length() - 1);
    618                     buffer.append(line);
    619                 }
    620                 else
    621                 {
    622                     buffer.append(line);
    623                     break;
    624                 }
    625             }
    626             return buffer.toString();
    627         }
    628
    629         /***
    630          * Parses the next property from the input stream and stores the found
    631          * name and value in internal fields. These fields can be obtained using
    632          * the provided getter methods. The return value indicates whether EOF
    633          * was reached (<b>false</b>) or whether further properties are
    634          * available (<b>true</b>).
    635          *
    636          * @return a flag if further properties are available
    637          * @throws IOException if an error occurs
    638          * @since 1.3
    639          */
    640         public boolean nextProperty() throws IOException
    641         {
    642             String line = readProperty();
    643
    644             if (line == null)
    645             {
    646                 return false; // EOF
    647             }
    648
    649             // parse the line
    650             String[] property = parseProperty(line);
    651             propertyName = StringEscapeUtils.unescapeJava(property[0]);
    652             propertyValue = unescapeJava(property[1], delimiter);
    653             return true;
    654         }
    655
    656         /***
    657          * Returns the comment lines that have been read for the last property.
    658          *
    659          * @return the comment lines for the last property returned by
    660          * <code>readProperty()</code>
    661          * @since 1.3
    662          */
    663         public List getCommentLines()
    664         {
    665             return commentLines;
    666         }
    667
    668         /***
    669          * Returns the name of the last read property. This method can be called
    670          * after <code>{@link #nextProperty()}</code> was invoked and its
    671          * return value was <b>true</b>.
    672          *
    673          * @return the name of the last read property
    674          * @since 1.3
    675          */
    676         public String getPropertyName()
    677         {
    678             return propertyName;
    679         }
    680
    681         /***
    682          * Returns the value of the last read property. This method can be
    683          * called after <code>{@link #nextProperty()}</code> was invoked and
    684          * its return value was <b>true</b>.
    685          *
    686          * @return the value of the last read property
    687          * @since 1.3
    688          */
    689         public String getPropertyValue()
    690         {
    691             return propertyValue;
    692         }
    693
    694         /***
    695          * Checks if the passed in line should be combined with the following.
    696          * This is true, if the line ends with an odd number of backslashes.
    697          *
    698          * @param line the line
    699          * @return a flag if the lines should be combined
    700          */
    701         private static boolean checkCombineLines(String line)
    702         {
    703             int bsCount = 0;
    704             for (int idx = line.length() - 1; idx >= 0 && line.charAt(idx) == '//'; idx--)
    705             {
    706                 bsCount++;
    707             }
    708
    709             return bsCount % 2 == 1;
    710         }
    711
    712         /***
    713          * Parse a property line and return the key and the value in an array.
    714          *
    715          * @param line the line to parse
    716          * @return an array with the property's key and value
    717          * @since 1.2
    718          */
    719         private static String[] parseProperty(String line)
    720         {
    721             // sorry for this spaghetti code, please replace it as soon as
    722             // possible with a regexp when the Java 1.3 requirement is dropped
    723
    724             String[] result = new String[2];
    725             StringBuffer key = new StringBuffer();
    726             StringBuffer value = new StringBuffer();
    727
    728             // state of the automaton:
    729             // 0: key parsing
    730             // 1: antislash found while parsing the key
    731             // 2: separator crossing
    732             // 3: value parsing
    733             int state = 0;
    734
    735             for (int pos = 0; pos < line.length(); pos++)
    736             {
    737                 char c = line.charAt(pos);
    738
    739                 switch (state)
    740                 {
    741                     case 0:
    742                         if (c == '//')
    743                         {
    744                             state = 1;
    745                         }
    746                         else if (ArrayUtils.contains(WHITE_SPACE, c))
    747                         {
    748                             // switch to the separator crossing state
    749                             state = 2;
    750                         }
    751                         else if (ArrayUtils.contains(SEPARATORS, c))
    752                         {
    753                             // switch to the value parsing state
    754                             state = 3;
    755                         }
    756                         else
    757                         {
    758                             key.append(c);
    759                         }
    760
    761                         break;
    762
    763                     case 1:
    764                         if (ArrayUtils.contains(SEPARATORS, c) || ArrayUtils.contains(WHITE_SPACE, c))
    765                         {
    766                             // this is an escaped separator or white space
    767                             key.append(c);
    768                         }
    769                         else
    770                         {
    771                             // another escaped character, the '\' is preserved
    772                             key.append('//');
    773                             key.append(c);
    774                         }
    775
    776                         // return to the key parsing state
    777                         state = 0;
    778
    779                         break;
    780
    781                     case 2:
    782                         if (ArrayUtils.contains(WHITE_SPACE, c))
    783                         {
    784                             // do nothing, eat all white spaces
    785                             state = 2;
    786                         }
    787                         else if (ArrayUtils.contains(SEPARATORS, c))
    788                         {
    789                             // switch to the value parsing state
    790                             state = 3;
    791                         }
    792                         else
    793                         {
    794                             // any other character indicates we encoutered the beginning of the value
    795                             value.append(c);
    796
    797                             // switch to the value parsing state
    798                             state = 3;
    799                         }
    800
    801                         break;
    802
    803                     case 3:
    804                         value.append(c);
    805                         break;
    806                 }
    807             }
    808
    809             result[0] = key.toString().trim();
    810             result[1] = value.toString().trim();
    811
    812             return result;
    813         }
    814     } // class PropertiesReader
    815
    816     /***
    817      * This class is used to write properties lines.
    818      */
    819     public static class PropertiesWriter extends FilterWriter
    820     {
    821         /*** The delimiter for multi-valued properties.*/
    822         private char delimiter;
    823
    824         /***
    825          * Constructor.
    826          *
    827          * @param writer a Writer object providing the underlying stream
    828          * @param delimiter the delimiter character for multi-valued properties
    829          */
    830         public PropertiesWriter(Writer writer, char delimiter)
    831         {
    832             super(writer);
    833             this.delimiter = delimiter;
    834         }
    835
    836         /***
    837          * Write a property.
    838          *
    839          * @param key the key of the property
    840          * @param value the value of the property
    841          *
    842          * @throws IOException if an I/O error occurs
    843          */
    844         public void writeProperty(String key, Object value) throws IOException
    845         {
    846             writeProperty(key, value, false);
    847         }
    848
    849         /***
    850          * Write a property.
    851          *
    852          * @param key The key of the property
    853          * @param values The array of values of the property
    854          *
    855          * @throws IOException if an I/O error occurs
    856          */
    857         public void writeProperty(String key, List values) throws IOException
    858         {
    859             for (int i = 0; i < values.size(); i++)
    860             {
    861                 writeProperty(key, values.get(i));
    862             }
    863         }
    864
    865         /***
    866          * Writes the given property and its value. If the value happens to be a
    867          * list, the <code>forceSingleLine</code> flag is evaluated. If it is
    868          * set, all values are written on a single line using the list delimiter
    869          * as separator.
    870          *
    871          * @param key the property key
    872          * @param value the property value
    873          * @param forceSingleLine the &quot;force single line&quot; flag
    874          * @throws IOException if an error occurs
    875          * @since 1.3
    876          */
    877         public void writeProperty(String key, Object value,
    878                 boolean forceSingleLine) throws IOException
    879         {
    880             String v;
    881
    882             if (value instanceof List)
    883             {
    884                 List values = (List) value;
    885                 if (forceSingleLine)
    886                 {
    887                     v = makeSingleLineValue(values);
    888                 }
    889                 else
    890                 {
    891                     writeProperty(key, values);
    892                     return;
    893                 }
    894             }
    895             else
    896             {
    897                 v = escapeValue(value);
    898             }
    899
    900             write(escapeKey(key));
    901             write(" = ");
    902             write(v);
    903
    904             writeln(null);
    905         }
    906
    907         /***
    908          * Write a comment.
    909          *
    910          * @param comment the comment to write
    911          * @throws IOException if an I/O error occurs
    912          */
    913         public void writeComment(String comment) throws IOException
    914         {
    915             writeln("# " + comment);
    916         }
    917
    918         /***
    919          * Escape the separators in the key.
    920          *
    921          * @param key the key
    922          * @return the escaped key
    923          * @since 1.2
    924          */
    925         private String escapeKey(String key)
    926         {
    927             StringBuffer newkey = new StringBuffer();
    928
    929             for (int i = 0; i < key.length(); i++)
    930             {
    931                 char c = key.charAt(i);
    932
    933                 if (ArrayUtils.contains(SEPARATORS, c) || ArrayUtils.contains(WHITE_SPACE, c))
    934                 {
    935                     // escape the separator
    936                     newkey.append('//');
    937                     newkey.append(c);
    938                 }
    939                 else
    940                 {
    941                     newkey.append(c);
    942                 }
    943             }
    944
    945             return newkey.toString();
    946         }
    947
    948         /***
    949          * Escapes the given property value. Delimiter characters in the value
    950          * will be escaped.
    951          *
    952          * @param value the property value
    953          * @return the escaped property value
    954          * @since 1.3
    955          */
    956         private String escapeValue(Object value)
    957         {
    958             String escapedValue = StringEscapeUtils.escapeJava(String.valueOf(value));
    959             if (delimiter != 0)
    960             {
    961                 escapedValue = StringUtils.replace(escapedValue, String.valueOf(delimiter), ESCAPE + delimiter);
    962             }
    963             return escapedValue;
    964         }
    965
    966         /***
    967          * Transforms a list of values into a single line value.
    968          *
    969          * @param values the list with the values
    970          * @return a string with the single line value (can be <b>null</b>)
    971          * @since 1.3
    972          */
    973         private String makeSingleLineValue(List values)
    974         {
    975             if (!values.isEmpty())
    976             {
    977                 Iterator it = values.iterator();
    978                 String lastValue = escapeValue(it.next());
    979                 StringBuffer buf = new StringBuffer(lastValue);
    980                 while (it.hasNext())
    981                 {
    982                     // if the last value ended with an escape character, it has
    983                     // to be escaped itself; otherwise the list delimiter will
    984                     // be escaped
    985                     if (lastValue.endsWith(ESCAPE))
    986                     {
    987                         buf.append(ESCAPE).append(ESCAPE);
    988                     }
    989                     buf.append(delimiter);
    990                     lastValue = escapeValue(it.next());
    991                     buf.append(lastValue);
    992                 }
    993                 return buf.toString();
    994             }
    995             else
    996             {
    997                 return null;
    998             }
    999         }
    1000
    1001         /***
    1002          * Helper method for writing a line with the platform specific line
    1003          * ending.
    1004          *
    1005          * @param s the content of the line (may be <b>null</b>)
    1006          * @throws IOException if an error occurs
    1007          * @since 1.3
    1008          */
    1009         public void writeln(String s) throws IOException
    1010         {
    1011             if (s != null)
    1012             {
    1013                 write(s);
    1014             }
    1015             write(LINE_SEPARATOR);
    1016         }
    1017
    1018     } // class PropertiesWriter
    1019
    1020     /***
    1021      * <p>Unescapes any Java literals found in the <code>String</code> to a
    1022      * <code>Writer</code>.</p> This is a slightly modified version of the
    1023      * StringEscapeUtils.unescapeJava() function in commons-lang that doesn't
    1024      * drop escaped separators (i.e '\,').
    1025      *
    1026      * @param str  the <code>String</code> to unescape, may be null
    1027      * @param delimiter the delimiter for multi-valued properties
    1028      * @return the processed string
    1029      * @throws IllegalArgumentException if the Writer is <code>null</code>
    1030      */
    1031     protected static String unescapeJava(String str, char delimiter)
    1032     {
    1033         if (str == null)
    1034         {
    1035             return null;
    1036         }
    1037         int sz = str.length();
    1038         StringBuffer out = new StringBuffer(sz);
    1039         StringBuffer unicode = new StringBuffer(UNICODE_LEN);
    1040         boolean hadSlash = false;
    1041         boolean inUnicode = false;
    1042         for (int i = 0; i < sz; i++)
    1043         {
    1044             char ch = str.charAt(i);
    1045             if (inUnicode)
    1046             {
    1047                 // if in unicode, then we're reading unicode
    1048                 // values in somehow
    1049                 unicode.append(ch);
    1050                 if (unicode.length() == UNICODE_LEN)
    1051                 {
    1052                     // unicode now contains the four hex digits
    1053                     // which represents our unicode character
    1054                     try
    1055                     {
    1056                         int value = Integer.parseInt(unicode.toString(), HEX_RADIX);
    1057                         out.append((char) value);
    1058                         unicode.setLength(0);
    1059                         inUnicode = false;
    1060                         hadSlash = false;
    1061                     }
    1062                     catch (NumberFormatException nfe)
    1063                     {
    1064                         throw new ConfigurationRuntimeException("Unable to parse unicode value: " + unicode, nfe);
    1065                     }
    1066                 }
    1067                 continue;
    1068             }
    1069
    1070             if (hadSlash)
    1071             {
    1072                 // handle an escaped value
    1073                 hadSlash = false;
    1074
    1075                 if (ch == '//')
    1076                 {
    1077                     out.append('//');
    1078                 }
    1079                 else if (ch == '\'')
    1080                 {
    1081                     out.append('\'');
    1082                 }
    1083                 else if (ch == '\"')
    1084                 {
    1085                     out.append('"');
    1086                 }
    1087                 else if (ch == 'r')
    1088                 {
    1089                     out.append('\r');
    1090                 }
    1091                 else if (ch == 'f')
    1092                 {
    1093                     out.append('\f');
    1094                 }
    1095                 else if (ch == 't')
    1096                 {
    1097                     out.append('\t');
    1098                 }
    1099                 else if (ch == 'n')
    1100                 {
    1101                     out.append('\n');
    1102                 }
    1103                 else if (ch == 'b')
    1104                 {
    1105                     out.append('\b');
    1106                 }
    1107                 else if (ch == delimiter)
    1108                 {
    1109                     out.append('//');
    1110                     out.append(delimiter);
    1111                 }
    1112                 else if (ch == 'u')
    1113                 {
    1114                     // uh-oh, we're in unicode country....
    1115                     inUnicode = true;
    1116                 }
    1117                 else
    1118                 {
    1119                     out.append(ch);
    1120                 }
    1121
    1122                 continue;
    1123             }
    1124             else if (ch == '//')
    1125             {
    1126                 hadSlash = true;
    1127                 continue;
    1128             }
    1129             out.append(ch);
    1130         }
    1131
    1132         if (hadSlash)
    1133         {
    1134             // then we're in the weird case of a \ at the end of the
    1135             // string, let's output it anyway.
    1136             out.append('//');
    1137         }
    1138
    1139         return out.toString();
    1140     }
    1141
    1142     /***
    1143      * Helper method for loading an included properties file. This method is
    1144      * called by <code>load()</code> when an <code>include</code> property
    1145      * is encountered. It tries to resolve relative file names based on the
    1146      * current base path. If this fails, a resolution based on the location of
    1147      * this properties file is tried.
    1148      *
    1149      * @param fileName the name of the file to load
    1150      * @throws ConfigurationException if loading fails
    1151      */
    1152     private void loadIncludeFile(String fileName) throws ConfigurationException
    1153     {
    1154         URL url = ConfigurationUtils.locate(getBasePath(), fileName);
    1155         if (url == null)
    1156         {
    1157             URL baseURL = getURL();
    1158             if (baseURL != null)
    1159             {
    1160                 url = ConfigurationUtils.locate(baseURL.toString(), fileName);
    1161             }
    1162         }
    1163
    1164         if (url == null)
    1165         {
    1166             throw new ConfigurationException("Cannot resolve include file "
    1167                     + fileName);
    1168         }
    1169         load(url);
    1170     }
    1171 }