As from the latest FindBugs, this warning (with High Priority) in hilited:
pivot/wtk/ApplicationContext.java:1201 pivot.wtk.ApplicationContext.resourceCache is or uses a map or set of URLs, which can be a performance hog
And from their doc related to this:
This method or field is or uses a Map or Set of URLs. Since both the equals and hashCode method of URL perform domain name resolution, this can result in a big performance hit.
See http://michaelscharf.blogspot.com/2006/11/javaneturlequals-and-hashcode-make.html for more information.
Consider using java.net.URI instead.
Trying to change URL with URI is ok here, but given compilation error in approx. 24 classes related to this.
Needs further study.