The Jar Scanner Component
Table of Contents
The Jar Scanner element represents the component that is used to scan the web application for JAR files and directories of class files. It is typically used during web application start to identify configuration files such as TLDs or web-fragment.xml files that must be processed as part of the web application initialisation.
A Jar Scanner element MAY be nested inside a Context component. If it is not included, a default Jar Scanner configuration will be created automatically, which is sufficient for most requirements.
All implementations of Jar Scanner support the following attributes:
Java class name of the implementation to use. This class must
The standard implementation of Jar Scanner is org.apache.tomcat.util.scan.StandardJarScanner. It supports the following additional attributes (in addition to the common attributes listed above):
If true, any directories found on the classpath will be checked to see
if are expanded JAR files. The default is
If true, any files found on the classpath will be checked to see if
they are Jar files rather than relying on the file extension being
If true, the full web application classpath, including the shared and
common classloaders and the system classpath (but not the bootstrap
classpath) will be scanned for Jar files in addition to the web
application. The default is
Only a Jar Scan Filter may be nested inside a Jar Scanner element.
No special features are associated with a Jar Scanner element.