src/main/java/org/jboss/util/xml/catalog/Catalog.java
public String resolveSystem(String systemId)
    throws MalformedURLException, IOException {

    catalogManager.debug.message(3, "resolveSystem("+systemId+")");

    systemId = normalizeURI(systemId);

    if (systemId != null && systemId.startsWith("urn:publicid:")) {
      systemId = PublicId.decodeURN(systemId);
      return resolvePublic(systemId, null);
    }

    // If there's a SYSTEM entry in this catalog, use it
    if (systemId != null) {
      String resolved = resolveLocalSystem(systemId);
      if (resolved != null) {
	return resolved;
      }
    }

    // Otherwise, look in the subordinate catalogs
    return resolveSubordinateCatalogs(SYSTEM,
				      null,
				      null,
				      systemId);
  }
public String resolveSystem(String systemId)
    throws MalformedURLException, IOException {

    catalogManager.debug.message(3, "resolveSystem("+systemId+")");

    systemId = normalizeURI(systemId);

    if (systemId != null && systemId.startsWith("urn:publicid:")) {
      systemId = PublicId.decodeURN(systemId);
      return resolvePublic(systemId, null);
    }

    // If there's a SYSTEM entry in this catalog, use it
    if (systemId != null) {
      String resolved = resolveLocalSystem(systemId);
      if (resolved != null) {
	return resolved;
      }
    }

    // Otherwise, look in the subordinate catalogs
    return resolveSubordinateCatalogs(SYSTEM,
				      null,
				      null,
				      systemId);
  }
Return the applicable SYSTEM system identifier.

<p>If a SYSTEM entry exists in the Catalog
for the system ID specified, return the mapped value.</p>

<p>On Windows-based operating systems, the comparison between
the system identifier provided and the SYSTEM entries in the
Catalog is case-insensitive.</p>

@param systemId The system ID to locate in the catalog.

@return The resolved system identifier.

@throws MalformedURLException The formal system identifier of a
subordinate catalog cannot be turned into a valid URL.
@throws IOException Error reading subordinate catalog file.