java.lang.IllegalArgumentException: Invalid <url-pattern> in servlet mapping

Question

<servlet>
    <servlet-name>myservlet</servlet-name>
    <servlet-class>workflow.WDispatcher</servlet-class>
    <load-on-startup>2</load-on-startup>
</servlet>

<servlet-mapping>
    <servlet-name>myservlet</servlet-name>
    <url-pattern>*NEXTEVENT*</url-pattern>
</servlet-mapping>

Above is the snippet from Tomcat's web.xml. The URL pattern *NEXTEVENT* on start up throws

java.lang.IllegalArgumentException: Invalid <url-pattern> in servlet mapping

It will be greatly appreciated if someone can hint at the error. ­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­­

Answer 1

<url-pattern>*NEXTEVENT*</url-pattern>

The URL pattern is not valid. It can either end in an asterisk or start with one (to denote a file extension mapping).

The url-pattern specification:

• A string beginning with a ‘/’ character and ending with a ‘/*’ suffix is used for path mapping.
• A string beginning with a ‘*.’ prefix is used as an extension mapping.
• A string containing only the ’/’ character indicates the "default" servlet of the application. In this case the servlet path is the request URI minus the context path and the path info is null.
• All other strings are used for exact matches only.

See section 12.2 of the Java Servlet Specification Version 3.1 for more details.

Answer 2

A workaround that can achieve that is to add a servlet filter to do URL re-writes e.g. re-write NEXTEVENT to /NEXTEVENT/(the one before the NEXTEVENT)/(the one after NEXTEVENT) or something similar.