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 * reserved comment block

 * DO NOT REMOVE OR ALTER!

 */

/*

 * 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.

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

import java.io.IOException;

import java.io.Serializable;

import com.sun.org.apache.xml.internal.res.XMLErrorResources;

import com.sun.org.apache.xml.internal.res.XMLMessages;

import java.util.Objects;

/**

 * A class to represent a Uniform Resource Identifier (URI). This class

 * is designed to handle the parsing of URIs and provide access to

 * the various components (scheme, host, port, userinfo, path, query

 * string and fragment) that may constitute a URI.

 * <p>

 * Parsing of a URI specification is done according to the URI

 * syntax described in RFC 2396

 * <http://www.ietf.org/rfc/rfc2396.txt?number=2396>. Every URI consists

 * of a scheme, followed by a colon (':'), followed by a scheme-specific

 * part. For URIs that follow the "generic URI" syntax, the scheme-

 * specific part begins with two slashes ("//") and may be followed

 * by an authority segment (comprised of user information, host, and

 * port), path segment, query segment and fragment. Note that RFC 2396

 * no longer specifies the use of the parameters segment and excludes

 * the "user:password" syntax as part of the authority segment. If

 * "user:password" appears in a URI, the entire user/password string

 * is stored as userinfo.

 * <p>

 * For URIs that do not follow the "generic URI" syntax (e.g. mailto),

 * the entire scheme-specific part is treated as the "path" portion

 * of the URI.

 * <p>

 * Note that, unlike the java.net.URL class, this class does not provide

 * any built-in network access functionality nor does it provide any

 * scheme-specific functionality (for example, it does not know a

 * default port for a specific scheme). Rather, it only knows the

 * grammar and basic set of operations that can be applied to a URI.

 *

 *

 */

public class URI implements Serializable

{

    static final long serialVersionUID = 7096266377907081897L;

  /**

   * MalformedURIExceptions are thrown in the process of building a URI

   * or setting fields on a URI when an operation would result in an

   * invalid URI specification.

   *

   */

  public static class MalformedURIException extends IOException

  {

    /**

     * Constructs a <code>MalformedURIException</code> with no specified

     * detail message.

     */

    public MalformedURIException()

    {

      super();

    }

    /**

     * Constructs a <code>MalformedURIException</code> with the

     * specified detail message.

     *

     * @param p_msg the detail message.

     */

    public MalformedURIException(String p_msg)

    {

      super(p_msg);

    }

  }

  /** reserved characters */

  private static final String RESERVED_CHARACTERS = ";/?:@&=+$,";

  /**

   * URI punctuation mark characters - these, combined with

   *   alphanumerics, constitute the "unreserved" characters

   */

  private static final String MARK_CHARACTERS = "-_.!~*'() ";

  /** scheme can be composed of alphanumerics and these characters */

  private static final String SCHEME_CHARACTERS = "+-.";

  /**

   * userinfo can be composed of unreserved, escaped and these

   *   characters

   */

  private static final String USERINFO_CHARACTERS = ";:&=+$,";

  /** Stores the scheme (usually the protocol) for this URI.

   *  @serial */

  private String m_scheme = null;

  /** If specified, stores the userinfo for this URI; otherwise null.

   *  @serial */

  private String m_userinfo = null;

  /** If specified, stores the host for this URI; otherwise null.

   *  @serial */

  private String m_host = null;

  /** If specified, stores the port for this URI; otherwise -1.

   *  @serial */

  private int m_port = -1;

  /** If specified, stores the path for this URI; otherwise null.

   *  @serial */

  private String m_path = null;

  /**

   * If specified, stores the query string for this URI; otherwise

   *   null.

   * @serial

   */

  private String m_queryString = null;

  /** If specified, stores the fragment for this URI; otherwise null.

   *  @serial */

  private String m_fragment = null;

  /** Indicate whether in DEBUG mode          */

  private static boolean DEBUG = false;

  /**

   * Construct a new and uninitialized URI.

   */

  public URI(){}

  /**

   * Construct a new URI from another URI. All fields for this URI are

   * set equal to the fields of the URI passed in.

   *

   * @param p_other the URI to copy (cannot be null)

   */

  public URI(URI p_other)

  {

    initialize(p_other);

  }

  /**

   * Construct a new URI from a URI specification string. If the

   * specification follows the "generic URI" syntax, (two slashes

   * following the first colon), the specification will be parsed

   * accordingly - setting the scheme, userinfo, host,port, path, query

   * string and fragment fields as necessary. If the specification does

   * not follow the "generic URI" syntax, the specification is parsed

   * into a scheme and scheme-specific part (stored as the path) only.

   *

   * @param p_uriSpec the URI specification string (cannot be null or

   *                  empty)

   *

   * @throws MalformedURIException if p_uriSpec violates any syntax

   *                                   rules

   */

  public URI(String p_uriSpec) throws MalformedURIException

  {

    this((URI) null, p_uriSpec);

  }

  /**

   * Construct a new URI from a base URI and a URI specification string.

   * The URI specification string may be a relative URI.

   *

   * @param p_base the base URI (cannot be null if p_uriSpec is null or

   *               empty)

   * @param p_uriSpec the URI specification string (cannot be null or

   *                  empty if p_base is null)

   *

   * @throws MalformedURIException if p_uriSpec violates any syntax

   *                                  rules

   */

  public URI(URI p_base, String p_uriSpec) throws MalformedURIException

  {

    initialize(p_base, p_uriSpec);

  }

  /**

   * Construct a new URI that does not follow the generic URI syntax.

   * Only the scheme and scheme-specific part (stored as the path) are

   * initialized.

   *

   * @param p_scheme the URI scheme (cannot be null or empty)

   * @param p_schemeSpecificPart the scheme-specific part (cannot be

   *                             null or empty)

   *

   * @throws MalformedURIException if p_scheme violates any

   *                                  syntax rules

   */

  public URI(String p_scheme, String p_schemeSpecificPart)

          throws MalformedURIException

  {

    if (p_scheme == null || p_scheme.trim().length() == 0)

    {

      throw new MalformedURIException(

        "Cannot construct URI with null/empty scheme!");

    }

    if (p_schemeSpecificPart == null

            || p_schemeSpecificPart.trim().length() == 0)

    {

      throw new MalformedURIException(

        "Cannot construct URI with null/empty scheme-specific part!");

    }

    setScheme(p_scheme);

    setPath(p_schemeSpecificPart);

  }

  /**

   * Construct a new URI that follows the generic URI syntax from its

   * component parts. Each component is validated for syntax and some

   * basic semantic checks are performed as well.  See the individual

   * setter methods for specifics.

   *

   * @param p_scheme the URI scheme (cannot be null or empty)

   * @param p_host the hostname or IPv4 address for the URI

   * @param p_path the URI path - if the path contains '?' or '#',

   *               then the query string and/or fragment will be

   *               set from the path; however, if the query and

   *               fragment are specified both in the path and as

   *               separate parameters, an exception is thrown

   * @param p_queryString the URI query string (cannot be specified

   *                      if path is null)

   * @param p_fragment the URI fragment (cannot be specified if path

   *                   is null)

   *

   * @throws MalformedURIException if any of the parameters violates

   *                                  syntax rules or semantic rules

   */

  public URI(String p_scheme, String p_host, String p_path, String p_queryString, String p_fragment)

          throws MalformedURIException

  {

    this(p_scheme, null, p_host, -1, p_path, p_queryString, p_fragment);

  }

  /**

   * Construct a new URI that follows the generic URI syntax from its

   * component parts. Each component is validated for syntax and some

   * basic semantic checks are performed as well.  See the individual

   * setter methods for specifics.

   *

   * @param p_scheme the URI scheme (cannot be null or empty)

   * @param p_userinfo the URI userinfo (cannot be specified if host

   *                   is null)

   * @param p_host the hostname or IPv4 address for the URI

   * @param p_port the URI port (may be -1 for "unspecified"; cannot

   *               be specified if host is null)

   * @param p_path the URI path - if the path contains '?' or '#',

   *               then the query string and/or fragment will be

   *               set from the path; however, if the query and

   *               fragment are specified both in the path and as

   *               separate parameters, an exception is thrown

   * @param p_queryString the URI query string (cannot be specified

   *                      if path is null)

   * @param p_fragment the URI fragment (cannot be specified if path

   *                   is null)

   *

   * @throws MalformedURIException if any of the parameters violates

   *                                  syntax rules or semantic rules

   */

  public URI(String p_scheme, String p_userinfo, String p_host, int p_port, String p_path, String p_queryString, String p_fragment)

          throws MalformedURIException

  {

    if (p_scheme == null || p_scheme.trim().length() == 0)

    {

      throw new MalformedURIException(XMLMessages.createXMLMessage(XMLErrorResources.ER_SCHEME_REQUIRED, null)); //"Scheme is required!");

    }

    if (p_host == null)

    {

      if (p_userinfo != null)

      {

        throw new MalformedURIException(

          XMLMessages.createXMLMessage(XMLErrorResources.ER_NO_USERINFO_IF_NO_HOST, null)); //"Userinfo may not be specified if host is not specified!");

      }

      if (p_port != -1)

      {

        throw new MalformedURIException(

          XMLMessages.createXMLMessage(XMLErrorResources.ER_NO_PORT_IF_NO_HOST, null)); //"Port may not be specified if host is not specified!");

      }

    }

    if (p_path != null)

    {

      if (p_path.indexOf('?') != -1 && p_queryString != null)

      {

        throw new MalformedURIException(

          XMLMessages.createXMLMessage(XMLErrorResources.ER_NO_QUERY_STRING_IN_PATH, null)); //"Query string cannot be specified in path and query string!");

      }

      if (p_path.indexOf('#') != -1 && p_fragment != null)

      {

        throw new MalformedURIException(

          XMLMessages.createXMLMessage(XMLErrorResources.ER_NO_FRAGMENT_STRING_IN_PATH, null)); //"Fragment cannot be specified in both the path and fragment!");

      }

    }

    setScheme(p_scheme);

    setHost(p_host);

    setPort(p_port);

    setUserinfo(p_userinfo);

    setPath(p_path);

    setQueryString(p_queryString);

    setFragment(p_fragment);

  }

  /**

   * Initialize all fields of this URI from another URI.

   *

   * @param p_other the URI to copy (cannot be null)

   */

  private void initialize(URI p_other)

  {

    m_scheme = p_other.getScheme();

    m_userinfo = p_other.getUserinfo();

    m_host = p_other.getHost();

    m_port = p_other.getPort();

    m_path = p_other.getPath();

    m_queryString = p_other.getQueryString();

    m_fragment = p_other.getFragment();

  }

  /**

   * Initializes this URI from a base URI and a URI specification string.

   * See RFC 2396 Section 4 and Appendix B for specifications on parsing

   * the URI and Section 5 for specifications on resolving relative URIs

   * and relative paths.

   *

   * @param p_base the base URI (may be null if p_uriSpec is an absolute

   *               URI)

   * @param p_uriSpec the URI spec string which may be an absolute or

   *                  relative URI (can only be null/empty if p_base

   *                  is not null)

   *

   * @throws MalformedURIException if p_base is null and p_uriSpec

   *                                  is not an absolute URI or if

   *                                  p_uriSpec violates syntax rules

   */

  private void initialize(URI p_base, String p_uriSpec)

          throws MalformedURIException

  {

    if (p_base == null

            && (p_uriSpec == null || p_uriSpec.trim().length() == 0))

    {

      throw new MalformedURIException(

        XMLMessages.createXMLMessage(XMLErrorResources.ER_CANNOT_INIT_URI_EMPTY_PARMS, null)); //"Cannot initialize URI with empty parameters.");

    }

    // just make a copy of the base if spec is empty

    if (p_uriSpec == null || p_uriSpec.trim().length() == 0)

    {

      initialize(p_base);

      return;

    }

    String uriSpec = p_uriSpec.trim();

    int uriSpecLen = uriSpec.length();

    int index = 0;

    // check for scheme

    int colonIndex = uriSpec.indexOf(':');

    if (colonIndex < 0)

    {

      if (p_base == null)

      {

        throw new MalformedURIException(XMLMessages.createXMLMessage(XMLErrorResources.ER_NO_SCHEME_IN_URI, new Object[]{uriSpec})); //"No scheme found in URI: "+uriSpec);

      }

    }

    else

    {

      initializeScheme(uriSpec);

      uriSpec = uriSpec.substring(colonIndex+1);

      // This is a fix for XALANJ-2059.

      if(m_scheme != null && p_base != null)

      {

        // a) If <uriSpec> starts with a slash (/), it means <uriSpec> is absolute

        //    and p_base can be ignored.

        //    For example,

        //    uriSpec = file:/myDIR/myXSLFile.xsl

        //    p_base = file:/myWork/

        //

        //    Here, uriSpec has absolute path after scheme file and :

        //    Hence p_base can be ignored.

        //

        // b) Similarily, according to RFC 2396, uri is resolved for <uriSpec> relative to <p_base>

        //    if scheme in <uriSpec> is same as scheme in <p_base>, else p_base can be ignored.

        //

        // c) if <p_base> is not hierarchical, it can be ignored.

        //

        if(uriSpec.startsWith("/") || !m_scheme.equals(p_base.m_scheme) || !p_base.getSchemeSpecificPart().startsWith("/"))

        {

          p_base = null;

        }

      }

      // Fix for XALANJ-2059

      uriSpecLen = uriSpec.length();

    }

    // two slashes means generic URI syntax, so we get the authority

    if (((index + 1) < uriSpecLen)

            && (uriSpec.substring(index).startsWith("//")))

    {

      index += 2;

      int startPos = index;

      // get authority - everything up to path, query or fragment

      char testChar = '\0';

      while (index < uriSpecLen)

      {

        testChar = uriSpec.charAt(index);

        if (testChar == '/' || testChar == '?' || testChar == '#')

        {

          break;

        }

        index++;

      }

      // if we found authority, parse it out, otherwise we set the

      // host to empty string

      if (index > startPos)

      {

        initializeAuthority(uriSpec.substring(startPos, index));

      }

      else

      {

        m_host = "";

      }

    }

    initializePath(uriSpec.substring(index));

    // Resolve relative URI to base URI - see RFC 2396 Section 5.2

    // In some cases, it might make more sense to throw an exception

    // (when scheme is specified is the string spec and the base URI

    // is also specified, for example), but we're just following the

    // RFC specifications

    if (p_base != null)

    {

      // check to see if this is the current doc - RFC 2396 5.2 #2

      // note that this is slightly different from the RFC spec in that

      // we don't include the check for query string being null

      // - this handles cases where the urispec is just a query

      // string or a fragment (e.g. "?y" or "#s") -

      // see <http://www.ics.uci.edu/~fielding/url/test1.html> which

      // identified this as a bug in the RFC

      if (m_path.length() == 0 && m_scheme == null && m_host == null)

      {

        m_scheme = p_base.getScheme();

        m_userinfo = p_base.getUserinfo();

        m_host = p_base.getHost();

        m_port = p_base.getPort();

        m_path = p_base.getPath();

        if (m_queryString == null)

        {

          m_queryString = p_base.getQueryString();

        }

        return;

      }

      // check for scheme - RFC 2396 5.2 #3

      // if we found a scheme, it means absolute URI, so we're done

      if (m_scheme == null)

      {

        m_scheme = p_base.getScheme();

      }

      // check for authority - RFC 2396 5.2 #4

      // if we found a host, then we've got a network path, so we're done

      if (m_host == null)

      {

        m_userinfo = p_base.getUserinfo();

        m_host = p_base.getHost();

        m_port = p_base.getPort();

      }

      else

      {

        return;

      }

      // check for absolute path - RFC 2396 5.2 #5

      if (m_path.length() > 0 && m_path.startsWith("/"))

      {

        return;

      }

      // if we get to this point, we need to resolve relative path

      // RFC 2396 5.2 #6

      String path = "";

      String basePath = p_base.getPath();