mirror of
https://github.com/apache/ant.git
synced 2025-05-17 13:35:43 +00:00
5337488612
git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@268652 13f79535-47bb-0310-9956-ffa450edef68
92 lines
3.5 KiB
HTML
92 lines
3.5 KiB
HTML
<html>
|
|
|
|
<head>
|
|
<meta http-equiv="Content-Language" content="en-us">
|
|
<title>Ant User Manual</title>
|
|
</head>
|
|
|
|
<body>
|
|
|
|
<h2><a name="available">Available</a></h2>
|
|
<h3>Description</h3>
|
|
<p>Sets a property if a resource is available at runtime. This resource can be a
|
|
file resource, a class in classpath or a JVM system resource.</p>
|
|
<p>If the resource is present, the property value is set to true by
|
|
default, otherwise the property is not set. You can set the value to
|
|
something specific by using the value attribute.</p>
|
|
<p>Normally, this task is used to set properties that are useful to avoid target
|
|
execution depending on system parameters.</p>
|
|
<h3>Parameters</h3>
|
|
<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">property</td>
|
|
<td valign="top">the name of the property to set.</td>
|
|
<td valign="top" align="center">Yes</td>
|
|
</tr>
|
|
<tr>
|
|
<td valign="top">value</td>
|
|
<td valign="top">the value to set the property to. Defaults to "true".</td>
|
|
<td valign="top" align="center">No</td>
|
|
</tr>
|
|
<tr>
|
|
<td valign="top">classname</td>
|
|
<td valign="top">the class to look for in classpath.</td>
|
|
<td valign="middle" align="center" rowspan="3">Yes</td>
|
|
</tr>
|
|
<tr>
|
|
<td valign="top">resource</td>
|
|
<td valign="top">the resource to look for in the JVM</td>
|
|
</tr>
|
|
<tr>
|
|
<td valign="top">file</td>
|
|
<td valign="top">the file to look for.</td>
|
|
</tr>
|
|
<tr>
|
|
<td valign="top">classpath</td> <td valign="top">the classpath to
|
|
use when looking up <code>classname</code>.</td> <td
|
|
align="center" valign="top">No</td>
|
|
</tr>
|
|
<tr>
|
|
<td valign="top">classpathref</td>
|
|
<td valign="top">the classpath to use, given as <a href="../using.html#references">reference</a> to a path defined elsewhere.</td>
|
|
<td align="center" valign="top">No</td>
|
|
</tr>
|
|
|
|
</table>
|
|
<h3>Parameters specified as nested elements</h3>
|
|
<h4>classpath</h4>
|
|
<p><code>Available</code>'s <i>classpath</i> attribute is a <a
|
|
href="../using.html#path">path-like structure</a> and can also be set via a nested
|
|
<i>classpath</i> element.</p>
|
|
<h3>Examples</h3>
|
|
<pre> <available classname="org.whatever.Myclass" property="Myclass.present"/></pre>
|
|
<p>sets the property <code><i>Myclass.present</i></code> to the value "true"
|
|
if the class <i>org.whatever.Myclass</i> is found in Ant's classpath.</p>
|
|
<pre>
|
|
<property name="jaxp.jar" value="./lib/jaxp11/jaxp.jar"/>
|
|
<available file="${jaxp.jar}" property="jaxp.jar.present"/>
|
|
</pre>
|
|
<p>sets the property <code><i>jaxp.jar.present</i></code> to the value "true"
|
|
if the file <i>./lib/jaxp11/jaxp.jar</i> is found.</p>
|
|
<pre>
|
|
...in project ...
|
|
<property name="jaxp.jar" value="./lib/jaxp11/jaxp.jar"/>
|
|
<path id="jaxp" location="${jaxp.jar}"/>
|
|
...in target ...
|
|
<available classname="javax.xml.transform.Transformer" classpathref="jaxp" property="jaxp11.present"/>
|
|
</pre>
|
|
<p>sets the property <code><i>jaxp11.present</i></code> to the value "true"
|
|
if the class <i>javax.xml.transform.Transformer</i> is found in the classpath referenced by <code>jaxp</code> (in this case, it is <code>./lib/jaxp11/jaxp.jar</code>).
|
|
</p>
|
|
<hr><p align="center">Copyright © 2000,2001 Apache Software Foundation. All rights
|
|
Reserved.</p>
|
|
|
|
</body>
|
|
</html>
|
|
|