ClassCastException when starting Tomcat with Struts2 Filter

[Kurt Kopf]

OS: Windows 7
Tomcat: 6.0.26
Struts 2.1.8.1
Java 1.6.0_20

Whenever I try and start up my app in Tomcat with a struts filter, I get the following exception:

java.lang.ClassCastException: org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter cannot be cast to javax.servlet.Filter
	at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
	at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422)
	at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115)
	at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:3838)
...

I actually had the same exception on my OS X box, but that was with Tomcat 6.0.24. When I upgraded to .26, everything worked fine. I'm using the same exact code base, libraries, etc, on the two machines but with no luck. Using the same major and minor Java versions as well, both compiled for 64-bit. I've tried going back to Tomcat .24 and .20 with no luck. I haven't tried going to Struts 2.0.x, but I'll probably try it out if no one has any suggestions.

Thanks in advance for your help, hopefully it's just something simple.

[Alpesh Padra]

Please verify your filter entries in web.xml since its comming while application loading.

[Kurt Kopf]

Here's my web.xml:

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
	xmlns="http://java.sun.com/xml/ns/javaee" xmlns:web="http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"
	id="WebApp_ID" version="2.5">
	
	<display-name>fbtest</display-name>

	<filter>
		<filter-name>struts2</filter-name>
		<filter-class>org.apache.struts2.dispatcher.ng.filter.StrutsPrepareAndExecuteFilter</filter-class>
	</filter>
	
	<filter-mapping>
		<filter-name>struts2</filter-name>
		<url-pattern>/*</url-pattern>
	</filter-mapping>
	
	<welcome-file-list>
		<welcome-file>index.jsp</welcome-file>
	</welcome-file-list>

</web-app>

Thanks for any insight =)

[David Newton]

What libraries are you deploying with your application?

[Kurt Kopf]

I figured out the issue. In OS X, Eclipse Galileo is 64-bit. In Win23, Galileo is only 32 bit. I had to upgrade Eclipse to Helios 64-bit (which means none of my SVN stuff works, but that's a completely different issue).

Thanks David, you actually sent me down the path that solved the issue.

[David Newton]

Glad you figured it out :) Yeah, most times when a totally bizarre issue like that pops up it's some form of library mismatch.