In order to use XML Catalogs with Xerces, the 
      Apache XML Commons Resolver: 
      resolver.jar needs to be on your classpath (or accessible
      in some other way to the ClassLoader). The resolver provides an implementation
      of OASIS XML Catalogs v1.1
      as well as some other catalog formats. The XML Commons Resolver 1.2 is included with 
      the binary distribution of Xerces. For information about interacting directly with 
      the Resolver's API visit the XML Commons
      site.
     
     
      As a convenience for users the parser provides a utility class:
      org.apache.xerces.util.XMLCatalogResolver which encapsulates
      the XML Commons Resolver exposing methods relevant to resolving XML entities.
      It implements the (org.apache.xerces.xni.parser.XMLEntityResolver)
      XNI entity resolver, the (org.xml.sax.EntityResolver) SAX entity resolver 
      and the (org.w3c.dom.ls.LSResourceResolver) DOM resource resolver
      interfaces. In XMLCatalogResolver the resolveEntity methods only query the 
      catalog for a mapping of the given identifier. These methods may be overridden if
      other behaviour is required.
     
     
      To use XMLCatalogResolver as an XNI EntityResolver you need
      to do something like this:
     
     |  |  |  | 
|  | import org.apache.xerces.util.XMLCatalogResolver;
import org.xml.sax.*;
...
XMLReader reader;
String [] catalogs =  
  {"file:///C:/catalog/cat1.xml", "file:///C:/catalog/cat2.xml"};
...
// Create catalog resolver and set a catalog list.
XMLCatalogResolver resolver = new XMLCatalogResolver();
resolver.setPreferPublic(true);
resolver.setCatalogList(catalogs);
// Set the resolver on the parser.
reader.setProperty(
  "http://apache.org/xml/properties/internal/entity-resolver", 
  resolver);
... |  | 
|  |  |  | 
      Note that setting an XNI entity resolver on a SAX or DOM parser will
      replace any type of entity resolver which was previously registered. If 
      some other type of resolver is registered on the parser it will replace 
      any XNI entity resolver previously registered.
     
     
      In addition to being used as an entity resolver, it is intended that 
      the XMLCatalogResolver may be used standalone to perform 
      catalog resolution outside of a parsing context. It may also be shared
      between several parsers and the application. See the API 
      documentation for details.
     
     |  | The XMLCatalogResolver class requires the XML Commons Resolver 1.1 
      or a version compatible with 1.1. |