public static JavaSpecVersion getMinJavaVersion( Path pluginDir )
    {
        final String value = getElementValue( pluginDir, "/plugin/minJavaVersion" );

        if ( value == null || value.trim().isEmpty() )
        {
            return null;
        }

        return new JavaSpecVersion( value );
    }
Returns the minimum Java specification version this plugin needs to run. The value is retrieved from the
plugin.xml file of the plugin. If the value could not be found, {@code null} will be returned.

@param pluginDir the path of the plugin directory.
@return the plugin's minimum Java version (possibly null).
xmppserver/src/main/java/org/jivesoftware/openfire/container/PluginMetadataHelper.java