The Apache Tomcat Servlet/JSP Container

Apache Tomcat 7

Version 7.0.42, Jul 2 2013
Apache Logo


Top Level Elements




Nested Components

Cluster Elements


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. 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.

Common Attributes

All implementations of Jar Scanner support the following attributes:


Java class name of the implementation to use. This class must implement the org.apache.tomcat.JarScanner interface. If not specified, the standard value (defined below) will be used.

Standard Implementation

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 false. Tomcat determines if directory is an expanded JAR file by looking for a META-INF sub-directory. Only if the META-INF sub-directory exists, is the directory to be an expanded JAR file.


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 .jar. The default is false


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 true.


If scanClassPath is true and this is true the bootstrap classpath will also be scanned for Jar files. The default is false.

Nested Components

No components may be nested inside a Jar Scanner element.

Special Features

No special features are associated with a Jar Scanner element.


Notice: This comments section collects your suggestions on improving documentation for Apache Tomcat.

If you have trouble and need help, read Find Help page and ask your question on the tomcat-users mailing list. Do not ask such questions here. This is not a Q&A section.

The Apache Comments System is explained here. Comments may be removed by our moderators if they are either implemented or considered invalid/off-topic.

Copyright © 1999-2013, Apache Software Foundation