Default value when "Failed to resolve expression: param" during deployment
<p>I've started using new java parameter by passing it with -Dparam and then using it in xml like this: <code>${param}</code>. Everything is great, but we have many servers and some of them doesn't pass this value and with new version of war artifact file using this it fails because of following error:</p>

<pre><code>Caused by: java.lang.IllegalStateException: Failed to resolve expression: ${param}
</code></pre>

<p>Is it possible to define default value for it to empty in xml? I can't change all server configuration to pass this param empty.</p>

<p>Update:</p>

<ul>
<li>Variable is passed at start of J2EE application server e.g. in jboss added line in standalone.conf: <code>$JAVA_OPTS="$JAVA_OPTS -Dparam=value"</code></li>
<li>It is used in WEB-INF/web.xml as ${param}</li>
<li>above error is raised when parameter is not passed during start of application server and I would prefer to create default value for this parameter in my artifact (prefered soultion is in web.xml)</li>
</ul>