/*
 * Copyright (c) 2011, 2017, Oracle and/or its affiliates. All rights reserved.
 */
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.sun.org.apache.xml.internal.resolver;

import java.io.IOException;
import java.io.InputStream;
import java.io.FileNotFoundException;
import java.util.Enumeration;
import java.util.Vector;
import java.net.URL;
import java.net.URLConnection;
import java.net.MalformedURLException;
import javax.xml.parsers.SAXParserFactory;
import com.sun.org.apache.xerces.internal.utils.SecuritySupport;
import com.sun.org.apache.xml.internal.resolver.readers.SAXCatalogReader;
import com.sun.org.apache.xml.internal.resolver.readers.OASISXMLCatalogReader;
import com.sun.org.apache.xml.internal.resolver.readers.TR9401CatalogReader;
import jdk.xml.internal.JdkXmlUtils;

An extension to OASIS Open Catalog files, this class supports
suffix-based matching and an external RFC2483 resolver.
Author:
Norman Walsh
Norman.Walsh@Sun.COM
See Also:
Catalog
Deprecated:
The JDK internal Catalog API in package com.sun.org.apache.xml.internal.resolver is encapsulated in JDK 9. The entire implementation under the package is now deprecated and subject to removal in a future release. Users of the API should migrate to the new public API. 

The new Catalog API is supported throughout the JDK XML Processors, which allows
the use of Catalog by simply setting a path to a Catalog file as a property.
Version:
1.0/**
 * An extension to OASIS Open Catalog files, this class supports
 * suffix-based matching and an external RFC2483 resolver.
 *
 * @see Catalog
 * @deprecated The JDK internal Catalog API in package
 * {@code com.sun.org.apache.xml.internal.resolver}
 * is encapsulated in JDK 9. The entire implementation under the package is now
 * deprecated and subject to removal in a future release. Users of the API
 * should migrate to the {@linkplain javax.xml.catalog new public API}.
 * <p>
 * The new Catalog API is supported throughout the JDK XML Processors, which allows
 * the use of Catalog by simply setting a path to a Catalog file as a property.
 *
 * @author Norman Walsh
 * <a href="mailto:Norman.Walsh@Sun.COM">Norman.Walsh@Sun.COM</a>
 *
 * @version 1.0
 */
@Deprecated(since="9", forRemoval=true)
public class Resolver extends Catalog {
  
The URISUFFIX Catalog Entry type.
URI suffix entries match URIs that end in a specified suffix.
/**
   * The URISUFFIX Catalog Entry type.
   *
   * <p>URI suffix entries match URIs that end in a specified suffix.</p>
   */
  public static final int URISUFFIX = CatalogEntry.addEntryType("URISUFFIX", 2);

  
The SYSTEMSUFFIX Catalog Entry type.
System suffix entries match system identifiers that end in a
specified suffix.
/**
   * The SYSTEMSUFFIX Catalog Entry type.
   *
   * <p>System suffix entries match system identifiers that end in a
   * specified suffix.</p>
   */
  public static final int SYSTEMSUFFIX = CatalogEntry.addEntryType("SYSTEMSUFFIX", 2);

  
The RESOLVER Catalog Entry type.
A hook for providing support for web-based backup resolvers.
/**
   * The RESOLVER Catalog Entry type.
   *
   * <p>A hook for providing support for web-based backup resolvers.</p>
   */
  public static final int RESOLVER = CatalogEntry.addEntryType("RESOLVER", 1);

  
The SYSTEMREVERSE Catalog Entry type.
This is a bit of a hack. There's no actual SYSTEMREVERSE entry,
but this entry type is used to indicate that a reverse lookup is
being performed. (This allows the Resolver to implement
RFC2483 I2N and I2NS.)
/**
   * The SYSTEMREVERSE Catalog Entry type.
   *
   * <p>This is a bit of a hack. There's no actual SYSTEMREVERSE entry,
   * but this entry type is used to indicate that a reverse lookup is
   * being performed. (This allows the Resolver to implement
   * RFC2483 I2N and I2NS.)
   */
  public static final int SYSTEMREVERSE
    = CatalogEntry.addEntryType("SYSTEMREVERSE", 1);

  
Setup readers.
/**
   * Setup readers.
   */
  public void setupReaders() {
    SAXParserFactory spf = JdkXmlUtils.getSAXFactory(catalogManager.overrideDefaultParser());
    spf.setValidating(false);

    SAXCatalogReader saxReader = new SAXCatalogReader(spf);

    saxReader.setCatalogParser(null, "XCatalog",
                               "com.sun.org.apache.xml.internal.resolver.readers.XCatalogReader");

    saxReader.setCatalogParser(OASISXMLCatalogReader.namespaceName,
                               "catalog",
                               "com.sun.org.apache.xml.internal.resolver.readers.ExtendedXMLCatalogReader");

    addReader("application/xml", saxReader);

    TR9401CatalogReader textReader = new TR9401CatalogReader();
    addReader("text/plain", textReader);
  }

  
Cleanup and process a Catalog entry.
This method processes each Catalog entry, changing mapped
relative system identifiers into absolute ones (based on the current
base URI), and maintaining other information about the current
catalog.
Params:
entry – The CatalogEntry to process./**
   * Cleanup and process a Catalog entry.
   *
   * <p>This method processes each Catalog entry, changing mapped
   * relative system identifiers into absolute ones (based on the current
   * base URI), and maintaining other information about the current
   * catalog.</p>
   *
   * @param entry The CatalogEntry to process.
   */
  public void addEntry(CatalogEntry entry) {
    int type = entry.getEntryType();

    if (type == URISUFFIX) {
      String suffix = normalizeURI(entry.getEntryArg(0));
      String fsi = makeAbsolute(normalizeURI(entry.getEntryArg(1)));

      entry.setEntryArg(1, fsi);

      catalogManager.debug.message(4, "URISUFFIX", suffix, fsi);
    } else if (type == SYSTEMSUFFIX) {
      String suffix = normalizeURI(entry.getEntryArg(0));
      String fsi = makeAbsolute(normalizeURI(entry.getEntryArg(1)));

      entry.setEntryArg(1, fsi);

      catalogManager.debug.message(4, "SYSTEMSUFFIX", suffix, fsi);
    }

    super.addEntry(entry);
  }

  
Return the applicable URI.
If a URI entry exists in the Catalog
for the URI specified, return the mapped value.
In the Resolver (as opposed to the Catalog) class, if the
URI isn't found by the usual algorithm, URISUFFIX entries are
considered.
URI comparison is case sensitive.
Params:
uri – The URI to locate in the catalog.
Throws:
MalformedURLException – The system identifier of a
subordinate catalog cannot be turned into a valid URL.
IOException – Error reading subordinate catalog file.
Returns:
The resolved URI./**
   * Return the applicable URI.
   *
   * <p>If a URI entry exists in the Catalog
   * for the URI specified, return the mapped value.</p>
   *
   * <p>In the Resolver (as opposed to the Catalog) class, if the
   * URI isn't found by the usual algorithm, URISUFFIX entries are
   * considered.</p>
   *
   * <p>URI comparison is case sensitive.</p>
   *
   * @param uri The URI to locate in the catalog.
   *
   * @return The resolved URI.
   *
   * @throws MalformedURLException The system identifier of a
   * subordinate catalog cannot be turned into a valid URL.
   * @throws IOException Error reading subordinate catalog file.
   */
  public String resolveURI(String uri)
    throws MalformedURLException, IOException {

    String resolved = super.resolveURI(uri);
    if (resolved != null) {
      return resolved;
    }

    Enumeration en = catalogEntries.elements();
    while (en.hasMoreElements()) {
      CatalogEntry e = (CatalogEntry) en.nextElement();
      if (e.getEntryType() == RESOLVER) {
        resolved = resolveExternalSystem(uri, e.getEntryArg(0));
        if (resolved != null) {
          return resolved;
        }
      } else if (e.getEntryType() == URISUFFIX) {
        String suffix = e.getEntryArg(0);
        String result = e.getEntryArg(1);

        if (suffix.length() <= uri.length()
            && uri.substring(uri.length()-suffix.length()).equals(suffix)) {
          return result;
        }
      }
    }

    // Otherwise, look in the subordinate catalogs
    return resolveSubordinateCatalogs(Catalog.URI,
                                      null,
                                      null,
                                      uri);
  }

  
Return the applicable SYSTEM system identifier, resorting
to external RESOLVERs if necessary.
If a SYSTEM entry exists in the Catalog
for the system ID specified, return the mapped value.
In the Resolver (as opposed to the Catalog) class, if the
URI isn't found by the usual algorithm, SYSTEMSUFFIX entries are
considered.
On Windows-based operating systems, the comparison between
the system identifier provided and the SYSTEM entries in the
Catalog is case-insensitive.
Params:
systemId – The system ID to locate in the catalog.
Throws:
MalformedURLException – The formal system identifier of a
subordinate catalog cannot be turned into a valid URL.
IOException – Error reading subordinate catalog file.
Returns:
The system identifier to use for systemId./**
   * Return the applicable SYSTEM system identifier, resorting
   * to external RESOLVERs if necessary.
   *
   * <p>If a SYSTEM entry exists in the Catalog
   * for the system ID specified, return the mapped value.</p>
   *
   * <p>In the Resolver (as opposed to the Catalog) class, if the
   * URI isn't found by the usual algorithm, SYSTEMSUFFIX entries are
   * considered.</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 system identifier to use for systemId.
   *
   * @throws MalformedURLException The formal system identifier of a
   * subordinate catalog cannot be turned into a valid URL.
   * @throws IOException Error reading subordinate catalog file.
   */
  public String resolveSystem(String systemId)
    throws MalformedURLException, IOException {

    String resolved = super.resolveSystem(systemId);
    if (resolved != null) {
      return resolved;
    }

    Enumeration en = catalogEntries.elements();
    while (en.hasMoreElements()) {
      CatalogEntry e = (CatalogEntry) en.nextElement();
      if (e.getEntryType() == RESOLVER) {
        resolved = resolveExternalSystem(systemId, e.getEntryArg(0));
        if (resolved != null) {
          return resolved;
        }
      } else if (e.getEntryType() == SYSTEMSUFFIX) {
        String suffix = e.getEntryArg(0);
        String result = e.getEntryArg(1);

        if (suffix.length() <= systemId.length()
            && systemId.substring(systemId.length()-suffix.length()).equals(suffix)) {
          return result;
        }
      }
    }

    return resolveSubordinateCatalogs(Catalog.SYSTEM,
                                      null,
                                      null,
                                      systemId);
  }

  
Return the applicable PUBLIC or SYSTEM identifier, resorting
to external resolvers if necessary.
This method searches the Catalog and returns the system
identifier specified for the given system or
public identifiers. If
no appropriate PUBLIC or SYSTEM entry is found in the Catalog,
null is returned.
Note that a system or public identifier in the current catalog
(or subordinate catalogs) will be used in preference to an
external resolver. Further, if a systemId is present, the external
resolver(s) will be queried for that before the publicId.
Params:
publicId – The public identifier to locate in the catalog.
Public identifiers are normalized before comparison.
systemId – The nominal system identifier for the entity
in question (as provided in the source document).
Throws:
MalformedURLException – The formal system identifier of a
subordinate catalog cannot be turned into a valid URL.
IOException – Error reading subordinate catalog file.
Returns:
The system identifier to use.
Note that the nominal system identifier is not returned if a
match is not found in the catalog, instead null is returned
to indicate that no match was found./**
   * Return the applicable PUBLIC or SYSTEM identifier, resorting
   * to external resolvers if necessary.
   *
   * <p>This method searches the Catalog and returns the system
   * identifier specified for the given system or
   * public identifiers. If
   * no appropriate PUBLIC or SYSTEM entry is found in the Catalog,
   * null is returned.</p>
   *
   * <p>Note that a system or public identifier in the current catalog
   * (or subordinate catalogs) will be used in preference to an
   * external resolver. Further, if a systemId is present, the external
   * resolver(s) will be queried for that before the publicId.</p>
   *
   * @param publicId The public identifier to locate in the catalog.
   * Public identifiers are normalized before comparison.
   * @param systemId The nominal system identifier for the entity
   * in question (as provided in the source document).
   *
   * @throws MalformedURLException The formal system identifier of a
   * subordinate catalog cannot be turned into a valid URL.
   * @throws IOException Error reading subordinate catalog file.
   *
   * @return The system identifier to use.
   * Note that the nominal system identifier is not returned if a
   * match is not found in the catalog, instead null is returned
   * to indicate that no match was found.
   */
  public String resolvePublic(String publicId, String systemId)
    throws MalformedURLException, IOException {

    String resolved = super.resolvePublic(publicId, systemId);
    if (resolved != null) {
      return resolved;
    }

    Enumeration en = catalogEntries.elements();
    while (en.hasMoreElements()) {
      CatalogEntry e = (CatalogEntry) en.nextElement();
      if (e.getEntryType() == RESOLVER) {
        if (systemId != null) {
          resolved = resolveExternalSystem(systemId,
                                           e.getEntryArg(0));
          if (resolved != null) {
            return resolved;
          }
        }
        resolved = resolveExternalPublic(publicId, e.getEntryArg(0));
        if (resolved != null) {
          return resolved;
        }
      }
    }

    return resolveSubordinateCatalogs(Catalog.PUBLIC,
                                      null,
                                      publicId,
                                      systemId);
  }

    
Query an external RFC2483 resolver for a system identifier.
Params:
systemId – The system ID to locate.
resolver – The name of the resolver to use.
Returns:
The system identifier to use for the systemId./**
     * Query an external RFC2483 resolver for a system identifier.
     *
     * @param systemId The system ID to locate.
     * @param resolver The name of the resolver to use.
     *
     * @return The system identifier to use for the systemId.
     */
    protected String resolveExternalSystem(String systemId, String resolver)
        throws MalformedURLException, IOException {
        Resolver r = queryResolver(resolver, "i2l", systemId, null);
        if (r != null) {
            return r.resolveSystem(systemId);
        } else {
            return null;
        }
    }

    
Query an external RFC2483 resolver for a public identifier.
Params:
publicId – The system ID to locate.
resolver – The name of the resolver to use.
Returns:
The system identifier to use for the systemId./**
     * Query an external RFC2483 resolver for a public identifier.
     *
     * @param publicId The system ID to locate.
     * @param resolver The name of the resolver to use.
     *
     * @return The system identifier to use for the systemId.
     */
    protected String resolveExternalPublic(String publicId, String resolver)
        throws MalformedURLException, IOException {
        Resolver r = queryResolver(resolver, "fpi2l", publicId, null);
        if (r != null) {
            return r.resolvePublic(publicId, null);
        } else {
            return null;
        }
    }

    
Query an external RFC2483 resolver.
Params:
resolver – The URL of the RFC2483 resolver.
command – The command to send the resolver.
arg1 – The first argument to the resolver.
arg2 – The second argument to the resolver, usually null.
Returns:
The Resolver constructed./**
     * Query an external RFC2483 resolver.
     *
     * @param resolver The URL of the RFC2483 resolver.
     * @param command The command to send the resolver.
     * @param arg1 The first argument to the resolver.
     * @param arg2 The second argument to the resolver, usually null.
     *
     * @return The Resolver constructed.
     */
    protected Resolver queryResolver(String resolver,
                                     String command,
                                     String arg1,
                                     String arg2) {
        InputStream iStream = null;
        String RFC2483 = resolver + "?command=" + command
            + "&format=tr9401&uri=" + arg1
            + "&uri2=" + arg2;
        String line = null;

        try {
            URL url = new URL(RFC2483);

            URLConnection urlCon = url.openConnection();

            urlCon.setUseCaches(false);

            Resolver r = (Resolver) newCatalog();

            String cType = urlCon.getContentType();

            // I don't care about the character set or subtype
            if (cType.indexOf(";") > 0) {
                cType = cType.substring(0, cType.indexOf(";"));
            }

            r.parseCatalog(cType, urlCon.getInputStream());

            return r;
        } catch (CatalogException cex) {
          if (cex.getExceptionType() == CatalogException.UNPARSEABLE) {
            catalogManager.debug.message(1, "Unparseable catalog: " + RFC2483);
          } else if (cex.getExceptionType()
                     == CatalogException.UNKNOWN_FORMAT) {
            catalogManager.debug.message(1, "Unknown catalog format: " + RFC2483);
          }
          return null;
        } catch (MalformedURLException mue) {
            catalogManager.debug.message(1, "Malformed resolver URL: " + RFC2483);
            return null;
        } catch (IOException ie) {
            catalogManager.debug.message(1, "I/O Exception opening resolver: " + RFC2483);
            return null;
        }
    }

    
Append two vectors, returning the result.
Params:
vec – The first vector
appvec – The vector to be appended
Returns:
The vector vec, with appvec's elements appended to it/**
     * Append two vectors, returning the result.
     *
     * @param vec The first vector
     * @param appvec The vector to be appended
     * @return The vector vec, with appvec's elements appended to it
     */
    private Vector appendVector(Vector vec, Vector appvec) {
        if (appvec != null) {
            for (int count = 0; count < appvec.size(); count++) {
                vec.addElement(appvec.elementAt(count));
            }
        }
        return vec;
    }

    
Find the URNs for a given system identifier in all catalogs.
Params:
systemId – The system ID to locate.
Returns:
A vector of URNs that map to the systemId./**
     * Find the URNs for a given system identifier in all catalogs.
     *
     * @param systemId The system ID to locate.
     *
     * @return A vector of URNs that map to the systemId.
     */
    public Vector resolveAllSystemReverse(String systemId)
        throws MalformedURLException, IOException {
        Vector resolved = new Vector();

        // If there's a SYSTEM entry in this catalog, use it
        if (systemId != null) {
            Vector localResolved = resolveLocalSystemReverse(systemId);
            resolved = appendVector(resolved, localResolved);
        }

        // Otherwise, look in the subordinate catalogs
        Vector subResolved = resolveAllSubordinateCatalogs(SYSTEMREVERSE,
                                                           null,
                                                           null,
                                                           systemId);

        return appendVector(resolved, subResolved);
    }

    
Find the URN for a given system identifier.
Params:
systemId – The system ID to locate.
Returns:
A (single) URN that maps to the systemId./**
     * Find the URN for a given system identifier.
     *
     * @param systemId The system ID to locate.
     *
     * @return A (single) URN that maps to the systemId.
     */
    public String resolveSystemReverse(String systemId)
        throws MalformedURLException, IOException {
        Vector resolved = resolveAllSystemReverse(systemId);
        if (resolved != null && resolved.size() > 0) {
            return (String) resolved.elementAt(0);
        } else {
            return null;
        }
    }

    
Return the applicable SYSTEM system identifiers.
If one or more SYSTEM entries exists in the Catalog
for the system ID specified, return the mapped values.
The caller is responsible for doing any necessary
normalization of the system identifier before calling
this method. For example, a relative system identifier in
a document might be converted to an absolute system identifier
before attempting to resolve it.
Note that this function will force all subordinate catalogs
to be loaded.
On Windows-based operating systems, the comparison between
the system identifier provided and the SYSTEM entries in the
Catalog is case-insensitive.
Params:
systemId – The system ID to locate in the catalog.
Throws:
MalformedURLException – The formal system identifier of a
subordinate catalog cannot be turned into a valid URL.
IOException – Error reading subordinate catalog file.
Returns:
The system identifier to use for the notation./**
     * Return the applicable SYSTEM system identifiers.
     *
     * <p>If one or more SYSTEM entries exists in the Catalog
     * for the system ID specified, return the mapped values.</p>
     *
     * <p>The caller is responsible for doing any necessary
     * normalization of the system identifier before calling
     * this method. For example, a relative system identifier in
     * a document might be converted to an absolute system identifier
     * before attempting to resolve it.</p>
     *
     * <p>Note that this function will force all subordinate catalogs
     * to be loaded.</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 system identifier to use for the notation.
     *
     * @throws MalformedURLException The formal system identifier of a
     * subordinate catalog cannot be turned into a valid URL.
     * @throws IOException Error reading subordinate catalog file.
     */
    public Vector resolveAllSystem(String systemId)
        throws MalformedURLException, IOException {
        Vector resolutions = new Vector();

        // If there are SYSTEM entries in this catalog, start with them
        if (systemId != null) {
            Vector localResolutions = resolveAllLocalSystem(systemId);
            resolutions = appendVector(resolutions, localResolutions);
        }

        // Then look in the subordinate catalogs
        Vector subResolutions = resolveAllSubordinateCatalogs(SYSTEM,
                                                              null,
                                                              null,
                                                              systemId);
        resolutions = appendVector(resolutions, subResolutions);

        if (resolutions.size() > 0) {
            return resolutions;
        } else {
            return null;
        }
    }

    
Return all applicable SYSTEM system identifiers in this
catalog.
If one or more SYSTEM entries exists in the catalog file
for the system ID specified, return the mapped values.
Params:
systemId – The system ID to locate in the catalog
Returns:
A vector of the mapped system identifiers or null/**
     * Return all applicable SYSTEM system identifiers in this
     * catalog.
     *
     * <p>If one or more SYSTEM entries exists in the catalog file
     * for the system ID specified, return the mapped values.</p>
     *
     * @param systemId The system ID to locate in the catalog
     *
     * @return A vector of the mapped system identifiers or null
     */
    private Vector resolveAllLocalSystem(String systemId) {
        Vector map = new Vector();
        String osname = SecuritySupport.getSystemProperty("os.name");
        boolean windows = (osname.indexOf("Windows") >= 0);
        Enumeration en = catalogEntries.elements();
        while (en.hasMoreElements()) {
            CatalogEntry e = (CatalogEntry) en.nextElement();
            if (e.getEntryType() == SYSTEM
                && (e.getEntryArg(0).equals(systemId)
                    || (windows
                        && e.getEntryArg(0).equalsIgnoreCase(systemId)))) {
                map.addElement(e.getEntryArg(1));
            }
        }
        if (map.size() == 0) {
            return null;
        } else {
            return map;
        }
    }

    
Find the URNs for a given system identifier in the current catalog.
Params:
systemId – The system ID to locate.
Returns:
A vector of URNs that map to the systemId./**
     * Find the URNs for a given system identifier in the current catalog.
     *
     * @param systemId The system ID to locate.
     *
     * @return A vector of URNs that map to the systemId.
     */
    private Vector resolveLocalSystemReverse(String systemId) {
        Vector map = new Vector();
        String osname = SecuritySupport.getSystemProperty("os.name");
        boolean windows = (osname.indexOf("Windows") >= 0);
        Enumeration en = catalogEntries.elements();
        while (en.hasMoreElements()) {
            CatalogEntry e = (CatalogEntry) en.nextElement();
            if (e.getEntryType() == SYSTEM
                && (e.getEntryArg(1).equals(systemId)
                    || (windows
                        && e.getEntryArg(1).equalsIgnoreCase(systemId)))) {
                map.addElement(e.getEntryArg(0));
            }
        }
        if (map.size() == 0) {
            return null;
        } else {
            return map;
        }
    }

    
Search the subordinate catalogs, in order, looking for all
match.
This method searches the Catalog and returns all of the system
identifiers specified for the given entity type with the given
name, public, and system identifiers. In some contexts, these
may be null.
Params:
entityType – The CatalogEntry type for which this query is
being conducted. This is necessary in order to do the approprate
query on a subordinate catalog.
entityName – The name of the entity being searched for, if
appropriate.
publicId – The public identifier of the entity in question
(as provided in the source document).
systemId – The nominal system identifier for the entity
in question (as provided in the source document).
Throws:
MalformedURLException – The formal system identifier of a
delegated catalog cannot be turned into a valid URL.
IOException – Error reading delegated catalog file.
Returns:
The system identifier to use.
Note that the nominal system identifier is not returned if a
match is not found in the catalog, instead null is returned
to indicate that no match was found./**
     * Search the subordinate catalogs, in order, looking for all
     * match.
     *
     * <p>This method searches the Catalog and returns all of the system
     * identifiers specified for the given entity type with the given
     * name, public, and system identifiers. In some contexts, these
     * may be null.</p>
     *
     * @param entityType The CatalogEntry type for which this query is
     * being conducted. This is necessary in order to do the approprate
     * query on a subordinate catalog.
     * @param entityName The name of the entity being searched for, if
     * appropriate.
     * @param publicId The public identifier of the entity in question
     * (as provided in the source document).
     * @param systemId The nominal system identifier for the entity
     * in question (as provided in the source document).
     *
     * @throws MalformedURLException The formal system identifier of a
     * delegated catalog cannot be turned into a valid URL.
     * @throws IOException Error reading delegated catalog file.
     *
     * @return The system identifier to use.
     * Note that the nominal system identifier is not returned if a
     * match is not found in the catalog, instead null is returned
     * to indicate that no match was found.
     */
    private synchronized Vector resolveAllSubordinateCatalogs(int entityType,
                                              String entityName,
                                              String publicId,
                                              String systemId)
        throws MalformedURLException, IOException {

        Vector resolutions = new Vector();

        for (int catPos = 0; catPos < catalogs.size(); catPos++) {
            Resolver c = null;

            try {
                c = (Resolver) catalogs.elementAt(catPos);
            } catch (ClassCastException e) {
                String catfile = (String) catalogs.elementAt(catPos);
                c = (Resolver) newCatalog();

                try {
                    c.parseCatalog(catfile);
                } catch (MalformedURLException mue) {
                    catalogManager.debug.message(1, "Malformed Catalog URL", catfile);
                } catch (FileNotFoundException fnfe) {
                    catalogManager.debug.message(1, "Failed to load catalog, file not found",
                          catfile);
                } catch (IOException ioe) {
                    catalogManager.debug.message(1, "Failed to load catalog, I/O error", catfile);
                }

                catalogs.setElementAt(c, catPos);
            }

            String resolved = null;

            // Ok, now what are we supposed to call here?
            if (entityType == DOCTYPE) {
                resolved = c.resolveDoctype(entityName,
                                            publicId,
                                            systemId);
                if (resolved != null) {
                    // Only find one DOCTYPE resolution
                    resolutions.addElement(resolved);
                    return resolutions;
                }
            } else if (entityType == DOCUMENT) {
                resolved = c.resolveDocument();
                if (resolved != null) {
                    // Only find one DOCUMENT resolution
                    resolutions.addElement(resolved);
                    return resolutions;
                }
            } else if (entityType == ENTITY) {
                resolved = c.resolveEntity(entityName,
                                           publicId,
                                           systemId);
                if (resolved != null) {
                    // Only find one ENTITY resolution
                    resolutions.addElement(resolved);
                    return resolutions;
                }
            } else if (entityType == NOTATION) {
                resolved = c.resolveNotation(entityName,
                                             publicId,
                                             systemId);
                if (resolved != null) {
                    // Only find one NOTATION resolution
                    resolutions.addElement(resolved);
                    return resolutions;
                }
            } else if (entityType == PUBLIC) {
                resolved = c.resolvePublic(publicId, systemId);
                if (resolved != null) {
                    // Only find one PUBLIC resolution
                    resolutions.addElement(resolved);
                    return resolutions;
                }
            } else if (entityType == SYSTEM) {
                Vector localResolutions = c.resolveAllSystem(systemId);
                resolutions = appendVector(resolutions, localResolutions);
                break;
            } else if (entityType == SYSTEMREVERSE) {
                Vector localResolutions = c.resolveAllSystemReverse(systemId);
                resolutions = appendVector(resolutions, localResolutions);
            }
        }

        if (resolutions != null) {
            return resolutions;
        } else {
            return null;
        }
    }
}