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<title>PropertyFile Task</title>
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<h1>PropertyFile</h1>
<hr>
<h2><a name="introduction">Introduction</a></h2>
<p>Apache Ant provides an optional task for editing property files. This is
very useful when wanting to make unattended modifications to
configuration files for application servers and
applications. Currently, the task maintains a working property file
with the ability to add properties or make changes to existing
ones. <em>Since Ant 1.8.0</em> comments and layout of the original properties
file are preserved.</p>
<p><em>Since Ant 1.8.2</em> the linefeed-style of the original file
will be preserved as well, as long as style used to be consistent.
In general, linefeeds of the updated file will be the same as the
first linefeed found when reading it.</p>
<hr>
<h2><a name="proptask">PropertyFile Task</a></h2>
<h3>Parameters</h3>
<table border="1" cellpadding="2" cellspacing="0">
<tr>
<td width="12%" valign="top"><b>Attribute</b></td>
<td width="78%" valign="top"><b>Description</b></td>
<td width="10%" valign="top"><b>Required</b></td>
</tr>
<tr>
<td width="12%" valign="top">file</td>
<td width="78%" valign="top">Location of the property file to be edited</td>
<td width="10%" valign="top">Yes</td>
</tr>
<tr>
<td width="12%" valign="top">comment</td>
<td width="78%" valign="top">Header for the file itself</td>
<td width="10%" valign="top">no</td>
</tr>
<tr>
<td width="12%" valign="top">jdkproperties</td>
<td width="78%" valign="top">Use java.lang.Properties, which will
loose comments and layout of file (default is 'false'). <em>since
Ant 1.8.0</em></td>
<td width="10%" valign="top">no</td>
</tr>
</table>
<p>The boolean attribute 'jdkproperties' is provided to recover the
previous behaviour of the task, in which the layout and any comments
in the properties file were lost by the task.</p>
<h3>Parameters specified as nested elements</h3>
<h4><a name="entryElement">Entry</a></h4>
<p>Use nested <code><entry></code>
elements to specify actual modifications to the property file itself.</p>
<table border="1" cellpadding="2" cellspacing="0">
<tr>
<td valign="top"><b>Attribute</b></td>
<td valign="top"><b>Description</b></td>
<td align="center" valign="top"><b>Required</b></td>
</tr>
<tr>
<td valign="top">key</td>
<td valign="top">Name of the property name/value pair</td>
<td valign="top" align="center">Yes</td>
</tr>
<tr>
<td valign="top">value</td>
<td valign="top">Value to set (=), to add (+) or subtract (-)</td>
<td valign="top" align="center" rowspan="2">At least one must be specified, if <i>operation</i> is not <i>delete</i></td>
</tr>
<tr>
<td valign="top">default</td>
<td valign="top">Initial value to set for a property if it is not
already defined in the property file.<br>
For type date, an additional keyword is allowed: "now"</td>
</tr>
<tr>
<td valign="top">type</td>
<td valign="top">Regard the value as : int, date or string (default)</td>
<td valign="top" align="center">No</td>
</tr>
<tr>
<td valign="top">operation</td>
<td valign="top">One of the following operations:<br><br>
<b>for all datatypes:</b><ul>
<li>"del" : deletes an entry</li>
<li>"+" : adds a value to the existing value</li>
<li>"=" : sets a value instead of the existing value (default)</li>
</ul><br><b>for date and int only:</b><ul>
<li>"-" : subtracts a value from the existing value</li>
</ul>
</td>
<td valign="top" align="center">No</td>
</tr>
<tr>
<td valign="top">pattern</td>
<td valign="top">For int and date type only. If present, Values will
be parsed and formatted accordingly.</td>
<td valign="top" align="center">No</td>
</tr>
<tr>
<td valign="top">unit</td>
<td valign="top">The unit of the value to be applied to date +/- operations.
Valid Values are:
<ul>
<li>millisecond</li>
<li>second</li>
<li>minute</li>
<li>hour</li>
<li>day (default)</li>
<li>week</li>
<li>month</li>
<li>year</li>
</ul>
This only applies to date types using a +/- operation.
</td>
<td align="center" valign="top">No</td>
</tr>
</table>
<p>The rules used when setting a property value are shown below. The
operation occurs <b>after</b> these rules are considered.</p>
<ul>
<li>If only value is specified, the property is set to it regardless of its
previous value.</li>
<li>If only default is specified and the property previously existed in the
property file, it is unchanged.</li>
<li>If only default is specified and the property did not exist in the
property file, the property is set to default.</li>
<li>If value and default are both specified and the property previously
existed in the property file, the property is set to value.</li>
<li>If value and default are both specified and the property did not exist in
the property file, the property is set to default.</li>
</ul>
<p> </p>
<h3>Examples</h3>
<p>The following changes the my.properties file. Assume my.properties look like:</p>
<pre># A string value
akey=original value
# The following is a counter, which will be incremented by 1 for
# each time the build is run.
anint=1</pre>
<p>After running, the file would now look like
</p>
<pre>#My properties
#Wed Aug 31 13:47:19 BST 2005
# A string value
akey=avalue
# The following is a counter, which will be incremented by 1 for
# each time the build is run.
anint=2
adate=2005/08/31 13\:47
formated.int=0014
formated.date=243 13\:47</pre>
<p>
The slashes conform to the expectations of the Properties class. The file will be stored in a manner so that each character is examined and escaped if necessary.
</p>
<p>
The layout and comment of the original file is preserved. New properties are added at the end of the file. Existing properties are overwritten in place.
</p>
<blockquote><pre><propertyfile
file="my.properties"
comment="My properties">
<entry key="akey" value="avalue"/>
<entry key="adate" type="date" value="now"/>
<entry key="anint" type="int" default="0" operation="+"/>
<entry key="formated.int" type="int" default="0013" operation="+" pattern="0000"/>
<entry key="formated.date" type="date" value="now" pattern="DDD HH:mm"/>
</propertyfile>
</pre></blockquote>
<p>
To produce dates relative from today :</p>
<blockquote><pre><propertyfile
file="my.properties"
comment="My properties">
<entry key="formated.date-1"
type="date" default="now" pattern="DDD"
operation="-" value="1"/>
<entry key="formated.tomorrow"
type="date" default="now" pattern="DDD"
operation="+" value="1"/>
</propertyfile>
</pre></blockquote>
<p>
Concatenation of strings :</p>
<blockquote><pre><propertyfile
file="my.properties"
comment="My properties">
<entry key="progress" default="" operation="+" value="."/>
</propertyfile>
</pre></blockquote>
<p>Each time called, a "." will be appended to "progress"
</p>
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