src/main/java/org/jboss/util/xml/catalog/helpers/BootstrapResolver.java
public InputSource resolveEntity (String publicId, String systemId) {
    String resolved = null;

    if (systemId != null && systemMap.containsKey(systemId)) {
      resolved = (String) systemMap.get(systemId);
    } else if (publicId != null && publicMap.containsKey(publicId)) {
      resolved = (String) publicMap.get(publicId);
    }

    if (resolved != null) {
      try {
	InputSource iSource = new InputSource(resolved);
	iSource.setPublicId(publicId);

	// Ideally this method would not attempt to open the
	// InputStream, but there is a bug (in Xerces, at least)
	// that causes the parser to mistakenly open the wrong
	// system identifier if the returned InputSource does
	// not have a byteStream.
	//
	// It could be argued that we still shouldn't do this here,
	// but since the purpose of calling the entityResolver is
	// almost certainly to open the input stream, it seems to
	// do little harm.
	//
	URL url = new URL(resolved);
	InputStream iStream = url.openStream();
	iSource.setByteStream(iStream);

	return iSource;
      } catch (Exception e) {
	// FIXME: silently fail?
	return null;
      }
    }

    return null;
  }
public InputSource resolveEntity (String publicId, String systemId) {
    String resolved = null;

    if (systemId != null && systemMap.containsKey(systemId)) {
      resolved = (String) systemMap.get(systemId);
    } else if (publicId != null && publicMap.containsKey(publicId)) {
      resolved = (String) publicMap.get(publicId);
    }

    if (resolved != null) {
      try {
	InputSource iSource = new InputSource(resolved);
	iSource.setPublicId(publicId);

	// Ideally this method would not attempt to open the
	// InputStream, but there is a bug (in Xerces, at least)
	// that causes the parser to mistakenly open the wrong
	// system identifier if the returned InputSource does
	// not have a byteStream.
	//
	// It could be argued that we still shouldn't do this here,
	// but since the purpose of calling the entityResolver is
	// almost certainly to open the input stream, it seems to
	// do little harm.
	//
	URL url = new URL(resolved);
	InputStream iStream = url.openStream();
	iSource.setByteStream(iStream);

	return iSource;
      } catch (Exception e) {
	// FIXME: silently fail?
	return null;
      }
    }

    return null;
  }
SAX resolveEntity API.