Deploying a Seam 2 application with Resteasy (deployed as JAR withing EarContent/lib) actually causes the following issue:

• When Seam access classes such as CacheControl, Cookie, EntityTag, MediaType or NewCookie, it loads my application's Resteasy classes, as using the CurrentThread's context class loader.
• So I ended up with the static field delegate of those classes keeping a reference to my application's class loader which cause a CL Memory Leak.

Since, the javax.ws.rs.core.Cookie/Entitytag, etc.. are server side components, I don't think they should refer to any deployed application.

To avoid this, the only way to do so, was at the server start-up to initialize those components in that way:

try {
    javax.ws.rs.core.CacheControl.valueOf("");
} catch (IllegalArgumentException e) {

}
try {
    javax.ws.rs.core.Cookie.valueOf("");
} catch (IllegalArgumentException e) {

}
try {
    javax.ws.rs.core.EntityTag.valueOf("");
} catch (IllegalArgumentException e) {

}
try {
    javax.ws.rs.core.MediaType.valueOf("");
} catch (IllegalArgumentException e) {

}
try {
    javax.ws.rs.core.NewCookie.valueOf("");
} catch (IllegalArgumentException e) {

}

(I put this in org.jboss.as.server.Main before line 91, but this is not the best place of course. Perhaps a class such as JreMemoryLeakPreventionListener should be used, but for the moment the use of this listener is disabled in JBoss Web 7, see https://community.jboss.org/thread/164760 )

But, since the RuntimeDelegate needed to find the Resteasy classed, I had to use the module ClassLoader instead of the current context class loader in the javax.ws.rs.ext.FactoryFinder.getContextClassLoader() method. Then, as the javax.ws.rs.api module actually depends on the org.jboss.resteasy.resteasy-jaxrs, this works well and avoids any dependency to my application's class loader.