catalog.java

来自「JAVA 所有包」· Java 代码 · 共 1,991 行 · 第 1/5 页

// Catalog.java - Represents OASIS Open Catalog files.

/*
 * Copyright 2001-2004 The Apache Software Foundation or its licensors,
 * as applicable.
 * 
 * Licensed 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.FileNotFoundException;
import java.io.InputStream;
import java.io.UnsupportedEncodingException;
import java.io.DataInputStream;

import java.util.Enumeration;
import java.util.Hashtable;
import java.util.Vector;

import java.net.URL;
import java.net.MalformedURLException;

import javax.xml.parsers.SAXParserFactory;

import com.sun.org.apache.xml.internal.resolver.CatalogManager;
import com.sun.org.apache.xml.internal.resolver.helpers.PublicId;
import com.sun.org.apache.xml.internal.resolver.readers.CatalogReader;
import com.sun.org.apache.xml.internal.resolver.readers.SAXCatalogReader;
import com.sun.org.apache.xml.internal.resolver.readers.TR9401CatalogReader;
import com.sun.org.apache.xml.internal.resolver.readers.OASISXMLCatalogReader;
import com.sun.org.apache.xml.internal.resolver.helpers.FileURL;

/**
 * Represents OASIS Open Catalog files.
 *
 * <p>This class implements the semantics of OASIS Open Catalog files
 * (defined by
 * <a href="http://www.oasis-open.org/html/a401.htm">OASIS Technical
 * Resolution 9401:1997 (Amendment 2 to TR 9401)</a>).</p>
 *
 * <p>The primary purpose of the Catalog is to associate resources in the
 * document with local system identifiers. Some entities
 * (document types, XML entities, and notations) have names and all of them
 * can have either public or system identifiers or both. (In XML, only a
 * notation can have a public identifier without a system identifier, but
 * the methods implemented in this class obey the Catalog semantics
 * from the SGML
 * days when system identifiers were optional.)</p>
 *
 * <p>The system identifiers returned by the resolution methods in this
 * class are valid, i.e. usable by, and in fact constructed by, the
 * <tt>java.net.URL</tt> class. Unfortunately, this class seems to behave in
 * somewhat non-standard ways and the system identifiers returned may
 * not be directly usable in a browser or filesystem context.
 *
 * <p>This class recognizes all of the Catalog entries defined in
 * TR9401:1997:</p>
 *
 * <ul>
 * <li><b>BASE</b>
 * changes the base URI for resolving relative system identifiers. The
 * initial base URI is the URI of the location of the catalog (which is,
 * in turn, relative to the location of the current working directory
 * at startup, as returned by the <tt>user.dir</tt> system property).</li>
 * <li><b>CATALOG</b>
 * processes other catalog files. An included catalog occurs logically
 * at the end of the including catalog.</li>
 * <li><b>DELEGATE_PUBLIC</b>
 * specifies alternate catalogs for some public identifiers. The delegated
 * catalogs are not loaded until they are needed, but they are cached
 * once loaded.</li>
 * <li><b>DELEGATE_SYSTEM</b>
 * specifies alternate catalogs for some system identifiers. The delegated
 * catalogs are not loaded until they are needed, but they are cached
 * once loaded.</li>
 * <li><b>DELEGATE_URI</b>
 * specifies alternate catalogs for some URIs. The delegated
 * catalogs are not loaded until they are needed, but they are cached
 * once loaded.</li>
 * <li><b>REWRITE_SYSTEM</b>
 * specifies alternate prefix for a system identifier.</li>
 * <li><b>REWRITE_URI</b>
 * specifies alternate prefix for a URI.</li>
 * <li><b>SYSTEM_SUFFIX</b>
 * maps any system identifier that ends with a particular suffix to another
 * system identifier.</li>
 * <li><b>URI_SUFFIX</b>
 * maps any URI that ends with a particular suffix to another URI.</li>
 * <li><b>DOCTYPE</b>
 * associates the names of root elements with URIs. (In other words, an XML
 * processor might infer the doctype of an XML document that does not include
 * a doctype declaration by looking for the DOCTYPE entry in the
 * catalog which matches the name of the root element of the document.)</li>
 * <li><b>DOCUMENT</b>
 * provides a default document.</li>
 * <li><b>DTDDECL</b>
 * recognized and silently ignored. Not relevant for XML.</li>
 * <li><b>ENTITY</b>
 * associates entity names with URIs.</li>
 * <li><b>LINKTYPE</b>
 * recognized and silently ignored. Not relevant for XML.</li>
 * <li><b>NOTATION</b>
 * associates notation names with URIs.</li>
 * <li><b>OVERRIDE</b>
 * changes the override behavior. Initial behavior is set by the
 * system property <tt>xml.catalog.override</tt>. The default initial
 * behavior is 'YES', that is, entries in the catalog override
 * system identifiers specified in the document.</li>
 * <li><b>PUBLIC</b>
 * maps a public identifier to a system identifier.</li>
 * <li><b>SGMLDECL</b>
 * recognized and silently ignored. Not relevant for XML.</li>
 * <li><b>SYSTEM</b>
 * maps a system identifier to another system identifier.</li>
 * <li><b>URI</b>
 * maps a URI to another URI.</li>
 * </ul>
 *
 * <p>Note that BASE entries are treated as described by RFC2396. In
 * particular, this has the counter-intuitive property that after a BASE
 * entry identifing "http://example.com/a/b/c" as the base URI,
 * the relative URI "foo" is resolved to the absolute URI
 * "http://example.com/a/b/foo". You must provide the trailing slash if
 * you do not want the final component of the path to be discarded as a
 * filename would in a URI for a resource: "http://example.com/a/b/c/".
 * </p>
 *
 * <p>Note that subordinate catalogs (all catalogs except the first,
 * including CATALOG and DELEGATE* catalogs) are only loaded if and when
 * they are required.</p>
 *
 * <p>This class relies on classes which implement the CatalogReader
 * interface to actually load catalog files. This allows the catalog
 * semantics to be implemented for TR9401 text-based catalogs, XML
 * catalogs, or any number of other storage formats.</p>
 *
 * <p>Additional catalogs may also be loaded with the
 * {@link #parseCatalog} method.</p>
 * </dd>
 * </dl>
 *
 * <p><b>Change Log:</b></p>
 * <dl>
 * <dt>2.0</dt>
 * <dd><p>Rewrite to use CatalogReaders.</p></dd>
 * <dt>1.1</dt>
 * <dd><p>Allow quoted components in <tt>xml.catalog.files</tt>
 * so that URLs containing colons can be used on Unix.
 * The string passed to <tt>xml.catalog.files</tt> can now have the form:</p>
 * <pre>
 * unquoted-path-with-no-sep-chars:"double-quoted path with or without sep chars":'single-quoted path with or without sep chars'
 * </pre>
 * <p>(Where ":" is the separater character in this example.)</p>
 * <p>If an unquoted path contains an embedded double or single quote
 * character, no special processig is performed on that character. No
 * path can contain separater characters, double, and single quotes
 * simultaneously.</p>
 * <p>Fix bug in calculation of BASE entries: if
 * a catalog contains multiple BASE entries, each is relative to the preceding
 * base, not the default base URI of the catalog.</p>
 * </dd>
 * <dt>1.0.1</dt>
 * <dd><p>Fixed a bug in the calculation of the list of subordinate catalogs.
 * This bug caused an infinite loop where parsing would alternately process
 * two catalogs indefinitely.</p>
 * </dd>
 * </dl>
 *
 * @see CatalogReader
 * @see CatalogEntry
 *
 * @author Norman Walsh
 * <a href="mailto:[e-mail]">[e-mail]</a>
 *
 * @version 1.0
 *
 * <p>Derived from public domain code originally published by Arbortext,
 * Inc.</p>
 */
public class Catalog {
  /** The BASE Catalog Entry type. */
  public static final int BASE     = CatalogEntry.addEntryType("BASE", 1);

  /** The CATALOG Catalog Entry type. */
  public static final int CATALOG  = CatalogEntry.addEntryType("CATALOG", 1);

  /** The DOCUMENT Catalog Entry type. */
  public static final int DOCUMENT = CatalogEntry.addEntryType("DOCUMENT", 1);

  /** The OVERRIDE Catalog Entry type. */
  public static final int OVERRIDE = CatalogEntry.addEntryType("OVERRIDE", 1);

  /** The SGMLDECL Catalog Entry type. */
  public static final int SGMLDECL = CatalogEntry.addEntryType("SGMLDECL", 1);

  /** The DELEGATE_PUBLIC Catalog Entry type. */
  public static final int DELEGATE_PUBLIC = CatalogEntry.addEntryType("DELEGATE_PUBLIC", 2);

  /** The DELEGATE_SYSTEM Catalog Entry type. */
  public static final int DELEGATE_SYSTEM = CatalogEntry.addEntryType("DELEGATE_SYSTEM", 2);

  /** The DELEGATE_URI Catalog Entry type. */
  public static final int DELEGATE_URI = CatalogEntry.addEntryType("DELEGATE_URI", 2);

  /** The DOCTYPE Catalog Entry type. */
  public static final int DOCTYPE  = CatalogEntry.addEntryType("DOCTYPE", 2);

  /** The DTDDECL Catalog Entry type. */
  public static final int DTDDECL  = CatalogEntry.addEntryType("DTDDECL", 2);

  /** The ENTITY Catalog Entry type. */
  public static final int ENTITY   = CatalogEntry.addEntryType("ENTITY", 2);

  /** The LINKTYPE Catalog Entry type. */
  public static final int LINKTYPE = CatalogEntry.addEntryType("LINKTYPE", 2);

  /** The NOTATION Catalog Entry type. */
  public static final int NOTATION = CatalogEntry.addEntryType("NOTATION", 2);

  /** The PUBLIC Catalog Entry type. */
  public static final int PUBLIC   = CatalogEntry.addEntryType("PUBLIC", 2);

  /** The SYSTEM Catalog Entry type. */
  public static final int SYSTEM   = CatalogEntry.addEntryType("SYSTEM", 2);

  /** The URI Catalog Entry type. */
  public static final int URI      = CatalogEntry.addEntryType("URI", 2);

  /** The REWRITE_SYSTEM Catalog Entry type. */
  public static final int REWRITE_SYSTEM = CatalogEntry.addEntryType("REWRITE_SYSTEM", 2);

  /** The REWRITE_URI Catalog Entry type. */
  public static final int REWRITE_URI = CatalogEntry.addEntryType("REWRITE_URI", 2);
  /** The SYSTEM_SUFFIX Catalog Entry type. */
  public static final int SYSTEM_SUFFIX = CatalogEntry.addEntryType("SYSTEM_SUFFIX", 2);
  /** The URI_SUFFIX Catalog Entry type. */
  public static final int URI_SUFFIX = CatalogEntry.addEntryType("URI_SUFFIX", 2);

  /**
   * The base URI for relative system identifiers in the catalog.
   * This may be changed by BASE entries in the catalog.
   */
  protected URL base;

  /** The base URI of the Catalog file currently being parsed. */
  protected URL catalogCwd;

  /** The catalog entries currently known to the system. */
  protected Vector catalogEntries = new Vector();

  /** The default initial override setting. */
  protected boolean default_override = true;

  /** The catalog manager in use for this instance. */
  protected CatalogManager catalogManager = CatalogManager.getStaticManager();

  /**
   * A vector of catalog files to be loaded.
   *
   * <p>This list is initially established by
   * <code>loadSystemCatalogs</code> when
   * it parses the system catalog list, but CATALOG entries may
   * contribute to it during the course of parsing.</p>
   *
   * @see #loadSystemCatalogs
   * @see #localCatalogFiles
   */
  protected Vector catalogFiles = new Vector();

  /**
   * A vector of catalog files constructed during processing of
   * CATALOG entries in the current catalog.
   *
   * <p>This two-level system is actually necessary to correctly implement
   * the semantics of the CATALOG entry. If one catalog file includes
   * another with a CATALOG entry, the included catalog logically
   * occurs <i>at the end</i> of the including catalog, and after any
   * preceding CATALOG entries. In other words, the CATALOG entry
   * cannot insert anything into the middle of a catalog file.</p>
   *
   * <p>When processing reaches the end of each catalog files, any
   * elements on this vector are added to the front of the
   * <code>catalogFiles</code> vector.</p>
   *
   * @see #catalogFiles
   */
  protected Vector localCatalogFiles = new Vector();

  /**
   * A vector of Catalogs.
   *
   * <p>The semantics of Catalog resolution are such that each
   * catalog is effectively a list of Catalogs (in other words,
   * a recursive list of Catalog instances).</p>
   *
   * <p>Catalogs that are processed as the result of CATALOG or
   * DELEGATE* entries are subordinate to the catalog that contained
   * them, but they may in turn have subordinate catalogs.</p>
   *
   * <p>Catalogs are only loaded when they are needed, so this vector
   * initially contains a list of Catalog filenames (URLs). If, during
   * processing, one of these catalogs has to be loaded, the resulting
   * Catalog object is placed in the vector, effectively caching it
   * for the next query.</p>
   */
  protected Vector catalogs = new Vector();

  /**
   * A vector of DELEGATE* Catalog entries constructed during
   * processing of the Catalog.
   *
   * <p>This two-level system has two purposes; first, it allows
   * us to sort the DELEGATE* entries by the length of the partial
   * public identifier so that a linear search encounters them in
   * the correct order and second, it puts them all at the end of
   * the Catalog.</p>
   *
   * <p>When processing reaches the end of each catalog file, any
   * elements on this vector are added to the end of the
   * <code>catalogEntries</code> vector. This assures that matching
   * PUBLIC keywords are encountered before DELEGATE* entries.</p>
   */
  protected Vector localDelegate = new Vector();

  /**
   * A hash of CatalogReaders.
   *
   * <p>This hash maps MIME types to elements in the readerArr
   * vector. This allows the Catalog to quickly locate the reader
   * for a particular MIME type.</p>
   */
  protected Hashtable readerMap = new Hashtable();

  /**
   * A vector of CatalogReaders.
   *
   * <p>This vector contains all of the readers in the order that they
   * were added. In the event that a catalog is read from a file, where
   * the MIME type is unknown, each reader is attempted in turn until
   * one succeeds.</p>
   */
  protected Vector readerArr = new Vector();

  /**
   * Constructs an empty Catalog.
   *
   * <p>The constructor interrogates the relevant system properties
   * using the default (static) CatalogManager
   * and initializes the catalog data structures.</p>
   */
  public Catalog() {
    // nop;
  }

  /**
   * Constructs an empty Catalog with a specific CatalogManager.
   *
   * <p>The constructor interrogates the relevant system properties
   * using the specified Catalog Manager
   * and initializes the catalog data structures.</p>
   */
  public Catalog(CatalogManager manager) {
    catalogManager = manager;
  }

  /**
   * Return the CatalogManager used by this catalog.
   *
   */
  public CatalogManager getCatalogManager() {
    return catalogManager;
  }

  /**
   * Establish the CatalogManager used by this catalog.
   *
   */
  public void setCatalogManager(CatalogManager manager) {
    catalogManager = manager;
  }

  /**
   * Setup readers.
   */
  public void setupReaders() {
    SAXParserFactory spf = SAXParserFactory.newInstance();
    spf.setNamespaceAware(true);