When Catalog is passed to XJC, it is used to resolve imported schemas while
building the forest, but during schema correctness check, it does not set the
entity resolver. In com.sun.tools.xjc.api.impl.s2j.SchemaCompilerImpl.java#230,
EntityResolver is not set on the SchemaFactory. This results in to unnecessary
warning thrown during schema resolution.
See the original issue filed on jax-ws: http://java.net/jira/browse/JAX_WS-900