I had a Seam application I was trying to migrate from AS 4.2 to 6 [this happened in 5 as well]. When I deployed the application, I kept getting the following error:
Caused by: java.util.zip.ZipException: error in opening zip file
at java.util.zip.ZipFile.open(Native Method) [:1.6.0_23]
at java.util.zip.ZipFile.<init>(ZipFile.java:127) [:1.6.0_23]
at java.util.zip.ZipFile.<init>(ZipFile.java:144) [:1.6.0_23]
at org.jboss.seam.deployment.URLScanner.handleArchiveByFile(URLScanner.java:123) [:2.2.1.Final]
... 80 more
The root issue is that there is a special Seam deployer bundled with JBoss ($JBOSS_HOME/server/*/deployers/seam.deployer), which is needed for deploying Seam applications. If the deployer is not used, you'll get the above ZipException [not sure why this is...].
In order to be called, the AS has to realize that an application is a Seam application. It does this based on the following directory entries [see: http://grepcode.com/file/repository.jboss.org/nexus/content/repositories/releases/org.jboss.seam.integration/jboss-seam-int-microcontainer/5.0.0.CR5/org/jboss/seam/integration/microcontainer/deployers/SeamUrlIntegrationDeployer.java]:
If it does *not* find one of those files, the Seam deployer is *not* called and the application will not deploy correctly.
My application happened to have those files bundled in a jar in the WEB-INF/lib directory. The application ran fine on AS 4.2 (and with JBoss tools). However, AS 6 was not able to determine that the application was a Seam application and was thus unable to properly deploy it.
I solved the problem by adding one of the above files to the *war* file. Once I did this, AS 6 properly deployed the app.
The issue can also be solved by bundling the jboss-seam-int-jbossas.jar in the WEB-INF/lib directory of the war.
[Original discussion: http://community.jboss.org/thread/164591]