Like SAX2's EntityResolver interface,
this interface lets  applications redirect references to external entities.
 
Java Binding:
package org.w3c.dom.ls;
public interface DOMEntityResolver {
  public DOMInputSource resolveEntity(String publicID, 
   String systemID, String baseURI) throws DOMSystemException;
}
IDL:
  interface DOMEntityResolver {
  DOMInputSource resolveEntity(in DOMString publicID, 
   in DOMString systemID, in DOMString baseURI)
   raises(DOMSystemException);
  };