public class DTDEntityResolver
extends Object
implements EntityResolver, Serializable

An EntityResolver implementation which attempts to resolve various systemId URLs to local classpath lookups

1. Any systemId URL beginning with http://www.hibernate.org/dtd/ is searched for as a classpath resource in the classloader which loaded the Hibernate classes.
2. Any systemId URL using classpath as the scheme (i.e. starting with classpath:// is searched for as a classpath resource using first the current thread context classloader and then the classloader which loaded the Hibernate classes.

Any entity references which cannot be resolved in relation to the above rules result in returning null, which should force the SAX reader to handle the entity reference in its default manner.