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<title>jarlib-available Task</title>
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<h2 id="jarlib-available">jarlib-available</h2>
<h3>Description</h3>
<p>Check whether an extension is present in a <code>fileset</code> or an <code>extensionSet</code>.
If the extension is present then a property is set.</p>

<p>Note that this task works with extensions as defined by the "Optional Package" specification.
For more information about optional packages, see the document <em>Optional Package Versioning</em>
in the documentation bundle for your Java Standard Edition package, in
file <samp>guide/extensions/versioning.html</samp> or the
online <a href="https://docs.oracle.com/javase/8/docs/technotes/guides/extensions/versioning.html"
target="_top">Extension and ExtensionSet documentation</a> for further details.</p>

<h3>Parameters</h3>
<table class="attr">
  <tr>
    <th scope="col">Attribute</th>
    <th scope="col">Description</th>
    <th scope="col">Required</th>
  </tr>
  <tr>
    <td>property</td>
    <td>The name of property to set if extensions is available</td>
    <td>Yes</td>
  </tr>
  <tr>
    <td>file</td>
    <td>The file to check for extension</td>
    <td>Yes, unless a nested
    <code>&lt;extensionSet&gt;</code> or <code>&lt;fileset&gt;</code> is specified</td>
  </tr>
</table>
<h3>Parameters specified as nested elements</h3>

<h4>extension</h4>
<p><a href="../Types/extension.html">Extension</a> the extension to search for.</p>

<h4>fileset</h4>
<p><a href="../Types/fileset.html">FileSet</a>s are used to select sets of files to check for
extension.</p>

<h4>extensionSet</h4>
<p><a href="../Types/extensionset.html">ExtensionSet</a>s is the set of extensions to search for
extension in.</p>

<h3>Examples</h3>
<p>Search for extension in single file</p>
<pre>
&lt;jarlib-available property=&quot;myext.present&quot; file=&quot;myfile.jar&quot;&gt;
  &lt;extension extensionName=&quot;org.apache.tools.ant&quot;
             specificationVersion=&quot;1.4.9&quot;
             specificationVendor=&quot;Apache Software Foundation&quot;/&gt;
&lt;/jarlib-available&gt;
</pre>

<p>Search for extension in single file referencing external Extension</p>
<pre>
&lt;extension id=&quot;myext&quot;
           extensionName=&quot;org.apache.tools.ant&quot;
           specificationVersion=&quot;1.4.9&quot;
           specificationVendor=&quot;Apache Software Foundation&quot;/&gt;

&lt;jarlib-available property=&quot;myext.present&quot; file=&quot;myfile.jar&quot;&gt;
  &lt;extension refid=&quot;myext&quot;/&gt;
&lt;/jarlib-available&gt;</pre>

<p>Search for extension in fileset</p>
<pre>
&lt;extension id=&quot;myext&quot;
           extensionName=&quot;org.apache.tools.ant&quot;
           specificationVersion=&quot;1.4.9&quot;
           specificationVendor=&quot;Apache Software Foundation&quot;/&gt;

&lt;jarlib-available property=&quot;myext.present&quot;&gt;
  &lt;extension refid=&quot;myext&quot;/&gt;
  &lt;fileset dir="lib"&gt;
    &lt;include name="*.jar"/&gt;
  &lt;/fileset&gt;
&lt;/jarlib-available&gt;</pre>

<p>Search for extension in extensionSet</p>
<pre>
&lt;extension id=&quot;myext&quot;
           extensionName=&quot;org.apache.tools.ant&quot;
           specificationVersion=&quot;1.4.9&quot;
           specificationVendor=&quot;Apache Software Foundation&quot;/&gt;

&lt;jarlib-available property=&quot;myext.present&quot;&gt;
  &lt;extension refid=&quot;myext&quot;/&gt;
  &lt;extensionSet id=&quot;exts3&quot;&gt;
    &lt;libfileset includeUrl=&quot;false&quot;
                includeImpl=&quot;true&quot;
                dir=&quot;lib&quot;&gt;
      &lt;include name=&quot;*.jar&quot;/&gt;
    &lt;/libfileset&gt;
  &lt;/extensionSet&gt;
&lt;/jarlib-available&gt;</pre>

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