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   *
   *  AndroidIDE is free software: you can redistribute it and/or modify
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   *  the Free Software Foundation, either version 3 of the License, or
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   *  AndroidIDE is distributed in the hope that it will be useful,
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   *  GNU General Public License for more details.
   *
   *  You should have received a copy of the GNU General Public License
   *   along with AndroidIDE.  If not, see <https://www.gnu.org/licenses/>.
   */
  
  /*
   * reserved comment block
   * DO NOT REMOVE OR ALTER!
   */
  /*
   * Copyright 1999-2004 The Apache Software Foundation.
   *
   * 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.
   */
  /*
   * $Id: URI.java,v 1.1.4.1 2005/09/08 11:03:20 suresh_emailid Exp $
   */
  package jaxp.sun.org.apache.xml.internal.serializer.utils;
  
  import java.io.IOException;
  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.
   *
   * This class is a copy of the one in com.sun.org.apache.xml.internal.utils.
   * It exists to cut the serializers dependancy on that package.
   *
   * A minor change from the original is that this class no longer implements
   * Serializable, and the serialVersionUID magic field is dropped, and
   * the class is no longer "public".
   *
   * @xsl.usage internal
   */
  final class URI
  {
    /**
     * 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(Utils.messages.createMessage(MsgKey.ER_SCHEME_REQUIRED, null)); //"Scheme is required!");
      }
  
      if (p_host == null)
      {
        if (p_userinfo != null)
        {
          throw new MalformedURIException(
            Utils.messages.createMessage(MsgKey.ER_NO_USERINFO_IF_NO_HOST, null)); //"Userinfo may not be specified if host is not specified!");
        }
  
        if (p_port != -1)
        {
          throw new MalformedURIException(
            Utils.messages.createMessage(MsgKey.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(
            Utils.messages.createMessage(MsgKey.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(
            Utils.messages.createMessage(MsgKey.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(
          Utils.messages.createMessage(MsgKey.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(Utils.messages.createMessage(MsgKey.ER_NO_SCHEME_IN_URI, new Object[]{uriSpec})); //"No scheme found in URI: "+uriSpec);
        }
      }
      else
      {
        initializeScheme(uriSpec);
        uriSpec = uriSpec.substring(colonIndex+1);
        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();
  
        // 6a - get all but the last segment of the base URI path
        if (basePath != null)
        {
          int lastSlash = basePath.lastIndexOf('/');
  
          if (lastSlash != -1)
          {
            path = basePath.substring(0, lastSlash + 1);
          }
        }
  
        // 6b - append the relative URI path
        path = path.concat(m_path);
  
        // 6c - remove all "./" where "." is a complete path segment
        index = -1;
  
        while ((index = path.indexOf("/./")) != -1)
        {
          path = path.substring(0, index + 1).concat(path.substring(index + 3));
        }
  
        // 6d - remove "." if path ends with "." as a complete path segment
        if (path.endsWith("/."))
        {
          path = path.substring(0, path.length() - 1);
        }
  
        // 6e - remove all "<segment>/../" where "<segment>" is a complete
        // path segment not equal to ".."
        index = -1;
  
        int segIndex = -1;
        String tempString = null;
  
        while ((index = path.indexOf("/../")) > 0)
        {
          tempString = path.substring(0, path.indexOf("/../"));
          segIndex = tempString.lastIndexOf('/');
  
          if (segIndex != -1)
          {
            if (!tempString.substring(segIndex++).equals(".."))
            {
              path = path.substring(0, segIndex).concat(path.substring(index
                      + 4));
            }
          }
        }
  
        // 6f - remove ending "<segment>/.." where "<segment>" is a
        // complete path segment
        if (path.endsWith("/.."))
        {
          tempString = path.substring(0, path.length() - 3);
          segIndex = tempString.lastIndexOf('/');
  
          if (segIndex != -1)
          {
            path = path.substring(0, segIndex + 1);
          }
        }
  
        m_path = path;
      }
    }
  
    /**
     * Initialize the scheme for this URI from a URI string spec.
     *
     * @param p_uriSpec the URI specification (cannot be null)
     *
     * @throws MalformedURIException if URI does not have a conformant
     *                                  scheme
     */
    private void initializeScheme(String p_uriSpec) throws MalformedURIException
    {
  
      int uriSpecLen = p_uriSpec.length();
      int index = 0;
      String scheme = null;
      char testChar = '\0';
  
      while (index < uriSpecLen)
      {
        testChar = p_uriSpec.charAt(index);
  
        if (testChar == ':' || testChar == '/' || testChar == '?'
                || testChar == '#')
        {
          break;
        }
  
        index++;
      }
  
      scheme = p_uriSpec.substring(0, index);
  
      if (scheme.length() == 0)
      {
        throw new MalformedURIException(Utils.messages.createMessage(MsgKey.ER_NO_SCHEME_INURI, null)); //"No scheme found in URI.");
      }
      else
      {
        setScheme(scheme);
      }
    }
  
    /**
     * Initialize the authority (userinfo, host and port) for this
     * URI from a URI string spec.
     *
     * @param p_uriSpec the URI specification (cannot be null)
     *
     * @throws MalformedURIException if p_uriSpec violates syntax rules
     */
    private void initializeAuthority(String p_uriSpec)
            throws MalformedURIException
    {
  
      int index = 0;
      int start = 0;
      int end = p_uriSpec.length();
      char testChar = '\0';
      String userinfo = null;
  
      // userinfo is everything up @
      if (p_uriSpec.indexOf('@', start) != -1)
      {
        while (index < end)
        {
          testChar = p_uriSpec.charAt(index);
  
          if (testChar == '@')
          {
            break;
          }
  
          index++;
        }
  
        userinfo = p_uriSpec.substring(start, index);
  
        index++;
      }
  
      // host is everything up to ':'
      String host = null;
  
      start = index;
  
      while (index < end)
      {
        testChar = p_uriSpec.charAt(index);
  
        if (testChar == ':')
        {
          break;
        }
  
        index++;
      }
  
      host = p_uriSpec.substring(start, index);
  
      int port = -1;
  
      if (host.length() > 0)
      {
  
        // port
        if (testChar == ':')
        {
          index++;
  
          start = index;
  
          while (index < end)
          {
            index++;
          }
  
          String portStr = p_uriSpec.substring(start, index);
  
          if (portStr.length() > 0)
          {
            for (int i = 0; i < portStr.length(); i++)
            {
              if (!isDigit(portStr.charAt(i)))
              {
                throw new MalformedURIException(
                  portStr + " is invalid. Port should only contain digits!");
              }
            }
  
            try
            {
              port = Integer.parseInt(portStr);
            }
            catch (NumberFormatException nfe)
            {
  
              // can't happen
            }
          }
        }
      }
  
      setHost(host);
      setPort(port);
      setUserinfo(userinfo);
    }
  
    /**
     * Initialize the path for this URI from a URI string spec.
     *
     * @param p_uriSpec the URI specification (cannot be null)
     *
     * @throws MalformedURIException if p_uriSpec violates syntax rules
     */
    private void initializePath(String p_uriSpec) throws MalformedURIException
    {
  
      if (p_uriSpec == null)
      {
        throw new MalformedURIException(
          "Cannot initialize path from null string!");
      }
  
      int index = 0;
      int start = 0;
      int end = p_uriSpec.length();
      char testChar = '\0';
  
      // path - everything up to query string or fragment
      while (index < end)
      {
        testChar = p_uriSpec.charAt(index);
  
        if (testChar == '?' || testChar == '#')
        {
          break;
        }
  
        // check for valid escape sequence
        if (testChar == '%')
        {
          if (index + 2 >= end ||!isHex(p_uriSpec.charAt(index + 1))
                  ||!isHex(p_uriSpec.charAt(index + 2)))
          {
            throw new MalformedURIException(
              Utils.messages.createMessage(MsgKey.ER_PATH_CONTAINS_INVALID_ESCAPE_SEQUENCE, null)); //"Path contains invalid escape sequence!");
          }
        }
        else if (!isReservedCharacter(testChar)
                 &&!isUnreservedCharacter(testChar))
        {
          if ('\\' != testChar)
            throw new MalformedURIException(Utils.messages.createMessage(MsgKey.ER_PATH_INVALID_CHAR, new Object[]{String.valueOf(testChar)})); //"Path contains invalid character: "
                                            //+ testChar);
        }
  
        index++;
      }
  
      m_path = p_uriSpec.substring(start, index);
  
      // query - starts with ? and up to fragment or end
      if (testChar == '?')
      {
        index++;
  
        start = index;
  
        while (index < end)
        {
          testChar = p_uriSpec.charAt(index);
  
          if (testChar == '#')
          {
            break;
          }
  
          if (testChar == '%')
          {
            if (index + 2 >= end ||!isHex(p_uriSpec.charAt(index + 1))
                    ||!isHex(p_uriSpec.charAt(index + 2)))
            {
              throw new MalformedURIException(
                "Query string contains invalid escape sequence!");
            }
          }
          else if (!isReservedCharacter(testChar)
                   &&!isUnreservedCharacter(testChar))
          {
            throw new MalformedURIException(
              "Query string contains invalid character:" + testChar);
          }
  
          index++;
        }
  
        m_queryString = p_uriSpec.substring(start, index);
      }
  
      // fragment - starts with #
      if (testChar == '#')
      {
        index++;
  
        start = index;
  
        while (index < end)
        {
          testChar = p_uriSpec.charAt(index);
  
          if (testChar == '%')
          {
            if (index + 2 >= end ||!isHex(p_uriSpec.charAt(index + 1))
                    ||!isHex(p_uriSpec.charAt(index + 2)))
            {
              throw new MalformedURIException(
                "Fragment contains invalid escape sequence!");
            }
          }
          else if (!isReservedCharacter(testChar)
                   &&!isUnreservedCharacter(testChar))
          {
            throw new MalformedURIException(
              "Fragment contains invalid character:" + testChar);
          }
  
          index++;
        }
  
        m_fragment = p_uriSpec.substring(start, index);
      }
    }
  
    /**
     * Get the scheme for this URI.
     *
     * @return the scheme for this URI
     */
    public String getScheme()
    {
      return m_scheme;
    }
  
    /**
     * Get the scheme-specific part for this URI (everything following the
     * scheme and the first colon). See RFC 2396 Section 5.2 for spec.
     *
     * @return the scheme-specific part for this URI
     */
    public String getSchemeSpecificPart()
    {
  
      final StringBuilder schemespec = new StringBuilder();
  
      if (m_userinfo != null || m_host != null || m_port != -1)
      {
        schemespec.append("//");
      }
  
      if (m_userinfo != null)
      {
        schemespec.append(m_userinfo);
        schemespec.append('@');
      }
  
      if (m_host != null)
      {
        schemespec.append(m_host);
      }
  
      if (m_port != -1)
      {
        schemespec.append(':');
        schemespec.append(m_port);
      }
  
      if (m_path != null)
      {
        schemespec.append((m_path));
      }
  
      if (m_queryString != null)
      {
        schemespec.append('?');
        schemespec.append(m_queryString);
      }
  
      if (m_fragment != null)
      {
        schemespec.append('#');
        schemespec.append(m_fragment);
      }
  
      return schemespec.toString();
    }
  
    /**
     * Get the userinfo for this URI.
     *
     * @return the userinfo for this URI (null if not specified).
     */
    public String getUserinfo()
    {
      return m_userinfo;
    }
  
    /**
     * Get the host for this URI.
     *
     * @return the host for this URI (null if not specified).
     */
    public String getHost()
    {
      return m_host;
    }
  
    /**
     * Get the port for this URI.
     *
     * @return the port for this URI (-1 if not specified).
     */
    public int getPort()
    {
      return m_port;
    }
  
    /**
     * Get the path for this URI (optionally with the query string and
     * fragment).
     *
     * @param p_includeQueryString if true (and query string is not null),
     *                             then a "?" followed by the query string
     *                             will be appended
     * @param p_includeFragment if true (and fragment is not null),
     *                             then a "#" followed by the fragment
     *                             will be appended
     *
     * @return the path for this URI possibly including the query string
     *         and fragment
     */
    public String getPath(boolean p_includeQueryString,
                          boolean p_includeFragment)
    {
  
      final StringBuilder pathString = new StringBuilder(m_path);
  
      if (p_includeQueryString && m_queryString != null)
      {
        pathString.append('?');
        pathString.append(m_queryString);
      }
  
      if (p_includeFragment && m_fragment != null)
      {
        pathString.append('#');
        pathString.append(m_fragment);
      }
  
      return pathString.toString();
    }
  
    /**
     * Get the path for this URI. Note that the value returned is the path
     * only and does not include the query string or fragment.
     *
     * @return the path for this URI.
     */
    public String getPath()
    {
      return m_path;
    }
  
    /**
     * Get the query string for this URI.
     *
     * @return the query string for this URI. Null is returned if there
     *         was no "?" in the URI spec, empty string if there was a
     *         "?" but no query string following it.
     */
    public String getQueryString()
    {
      return m_queryString;
    }
  
    /**
     * Get the fragment for this URI.
     *
     * @return the fragment for this URI. Null is returned if there
     *         was no "#" in the URI spec, empty string if there was a
     *         "#" but no fragment following it.
     */
    public String getFragment()
    {
      return m_fragment;
    }
  
    /**
     * Set the scheme for this URI. The scheme is converted to lowercase
     * before it is set.
     *
     * @param p_scheme the scheme for this URI (cannot be null)
     *
     * @throws MalformedURIException if p_scheme is not a conformant
     *                                  scheme name
     */
    public void setScheme(String p_scheme) throws MalformedURIException
    {
  
      if (p_scheme == null)
      {
        throw new MalformedURIException(Utils.messages.createMessage(MsgKey.ER_SCHEME_FROM_NULL_STRING, null)); //"Cannot set scheme from null string!");
      }
  
      if (!isConformantSchemeName(p_scheme))
      {
        throw new MalformedURIException(Utils.messages.createMessage(MsgKey.ER_SCHEME_NOT_CONFORMANT, null)); //"The scheme is not conformant.");
      }
  
      m_scheme = p_scheme.toLowerCase();
    }
  
    /**
     * Set the userinfo for this URI. If a non-null value is passed in and
     * the host value is null, then an exception is thrown.
     *
     * @param p_userinfo the userinfo for this URI
     *
     * @throws MalformedURIException if p_userinfo contains invalid
     *                                  characters
     */
    public void setUserinfo(String p_userinfo) throws MalformedURIException
    {
  
      if (p_userinfo == null)
      {
        m_userinfo = null;
      }
      else
      {
        if (m_host == null)
        {
          throw new MalformedURIException(
            "Userinfo cannot be set when host is null!");
        }
  
        // userinfo can contain alphanumerics, mark characters, escaped
        // and ';',':','&','=','+','$',','
        int index = 0;
        int end = p_userinfo.length();
        char testChar = '\0';
  
        while (index < end)
        {
          testChar = p_userinfo.charAt(index);
  
          if (testChar == '%')
          {
            if (index + 2 >= end ||!isHex(p_userinfo.charAt(index + 1))
                    ||!isHex(p_userinfo.charAt(index + 2)))
            {
              throw new MalformedURIException(
                "Userinfo contains invalid escape sequence!");
            }
          }
          else if (!isUnreservedCharacter(testChar)
                   && USERINFO_CHARACTERS.indexOf(testChar) == -1)
          {
            throw new MalformedURIException(
              "Userinfo contains invalid character:" + testChar);
          }
  
          index++;
        }
      }
  
      m_userinfo = p_userinfo;
    }
  
    /**
     * Set the host for this URI. If null is passed in, the userinfo
     * field is also set to null and the port is set to -1.
     *
     * @param p_host the host for this URI
     *
     * @throws MalformedURIException if p_host is not a valid IP
     *                                  address or DNS hostname.
     */
    public void setHost(String p_host) throws MalformedURIException
    {
  
      if (p_host == null || p_host.trim().length() == 0)
      {
        m_host = p_host;
        m_userinfo = null;
        m_port = -1;
      }
      else if (!isWellFormedAddress(p_host))
      {
        throw new MalformedURIException(Utils.messages.createMessage(MsgKey.ER_HOST_ADDRESS_NOT_WELLFORMED, null)); //"Host is not a well formed address!");
      }
  
      m_host = p_host;
    }
  
    /**
     * Set the port for this URI. -1 is used to indicate that the port is
     * not specified, otherwise valid port numbers are  between 0 and 65535.
     * If a valid port number is passed in and the host field is null,
     * an exception is thrown.
     *
     * @param p_port the port number for this URI
     *
     * @throws MalformedURIException if p_port is not -1 and not a
     *                                  valid port number
     */
    public void setPort(int p_port) throws MalformedURIException
    {
  
      if (p_port >= 0 && p_port <= 65535)
      {
        if (m_host == null)
        {
          throw new MalformedURIException(
            Utils.messages.createMessage(MsgKey.ER_PORT_WHEN_HOST_NULL, null)); //"Port cannot be set when host is null!");
        }
      }
      else if (p_port != -1)
      {
        throw new MalformedURIException(Utils.messages.createMessage(MsgKey.ER_INVALID_PORT, null)); //"Invalid port number!");
      }
  
      m_port = p_port;
    }
  
    /**
     * Set the path for this URI. If the supplied path is null, then the
     * query string and fragment are set to null as well. If the supplied
     * path includes a query string and/or fragment, these fields will be
     * parsed and set as well. Note that, for URIs following the "generic
     * URI" syntax, the path specified should start with a slash.
     * For URIs that do not follow the generic URI syntax, this method
     * sets the scheme-specific part.
     *
     * @param p_path the path for this URI (may be null)
     *
     * @throws MalformedURIException if p_path contains invalid
     *                                  characters
     */
    public void setPath(String p_path) throws MalformedURIException
    {
  
      if (p_path == null)
      {
        m_path = null;
        m_queryString = null;
        m_fragment = null;
      }
      else
      {
        initializePath(p_path);
      }
    }
  
    /**
     * Append to the end of the path of this URI. If the current path does
     * not end in a slash and the path to be appended does not begin with
     * a slash, a slash will be appended to the current path before the
     * new segment is added. Also, if the current path ends in a slash
     * and the new segment begins with a slash, the extra slash will be
     * removed before the new segment is appended.
     *
     * @param p_addToPath the new segment to be added to the current path
     *
     * @throws MalformedURIException if p_addToPath contains syntax
     *                                  errors
     */
    public void appendPath(String p_addToPath) throws MalformedURIException
    {
  
      if (p_addToPath == null || p_addToPath.trim().length() == 0)
      {
        return;
      }
  
      if (!isURIString(p_addToPath))
      {
        throw new MalformedURIException(Utils.messages.createMessage(MsgKey.ER_PATH_INVALID_CHAR, new Object[]{p_addToPath})); //"Path contains invalid character!");
      }
  
      if (m_path == null || m_path.trim().length() == 0)
      {
        if (p_addToPath.startsWith("/"))
        {
          m_path = p_addToPath;
        }
        else
        {
          m_path = "/" + p_addToPath;
        }
      }
      else if (m_path.endsWith("/"))
      {
        if (p_addToPath.startsWith("/"))
        {
          m_path = m_path.concat(p_addToPath.substring(1));
        }
        else
        {
          m_path = m_path.concat(p_addToPath);
        }
      }
      else
      {
        if (p_addToPath.startsWith("/"))
        {
          m_path = m_path.concat(p_addToPath);
        }
        else
        {
          m_path = m_path.concat("/" + p_addToPath);
        }
      }
    }
  
    /**
     * Set the query string for this URI. A non-null value is valid only
     * if this is an URI conforming to the generic URI syntax and
     * the path value is not null.
     *
     * @param p_queryString the query string for this URI
     *
     * @throws MalformedURIException if p_queryString is not null and this
     *                                  URI does not conform to the generic
     *                                  URI syntax or if the path is null
     */
    public void setQueryString(String p_queryString)
            throws MalformedURIException
    {
  
      if (p_queryString == null)
      {
        m_queryString = null;
      }
      else if (!isGenericURI())
      {
        throw new MalformedURIException(
          "Query string can only be set for a generic URI!");
      }
      else if (getPath() == null)
      {
        throw new MalformedURIException(
          "Query string cannot be set when path is null!");
      }
      else if (!isURIString(p_queryString))
      {
        throw new MalformedURIException(
          "Query string contains invalid character!");
      }
      else
      {
        m_queryString = p_queryString;
      }
    }
  
    /**
     * Set the fragment for this URI. A non-null value is valid only
     * if this is a URI conforming to the generic URI syntax and
     * the path value is not null.
     *
     * @param p_fragment the fragment for this URI
     *
     * @throws MalformedURIException if p_fragment is not null and this
     *                                  URI does not conform to the generic
     *                                  URI syntax or if the path is null
     */
    public void setFragment(String p_fragment) throws MalformedURIException
    {
  
      if (p_fragment == null)
      {
        m_fragment = null;
      }
      else if (!isGenericURI())
      {
        throw new MalformedURIException(
          Utils.messages.createMessage(MsgKey.ER_FRAG_FOR_GENERIC_URI, null)); //"Fragment can only be set for a generic URI!");
      }
      else if (getPath() == null)
      {
        throw new MalformedURIException(
          Utils.messages.createMessage(MsgKey.ER_FRAG_WHEN_PATH_NULL, null)); //"Fragment cannot be set when path is null!");
      }
      else if (!isURIString(p_fragment))
      {
        throw new MalformedURIException(Utils.messages.createMessage(MsgKey.ER_FRAG_INVALID_CHAR, null)); //"Fragment contains invalid character!");
      }
      else
      {
        m_fragment = p_fragment;
      }
    }
  
    /**
     * Determines if the passed-in Object is equivalent to this URI.
     *
     * @param p_test the Object to test for equality.
     *
     * @return true if p_test is a URI with all values equal to this
     *         URI, false otherwise
     */
    @Override
    public boolean equals(Object p_test)
    {
  
      if (p_test instanceof URI)
      {
        URI testURI = (URI) p_test;
  
        if (((m_scheme == null && testURI.m_scheme == null) || (m_scheme != null && testURI.m_scheme != null && m_scheme.equals(
                testURI.m_scheme))) && ((m_userinfo == null && testURI.m_userinfo == null) || (m_userinfo != null && testURI.m_userinfo != null && m_userinfo.equals(
                testURI.m_userinfo))) && ((m_host == null && testURI.m_host == null) || (m_host != null && testURI.m_host != null && m_host.equals(
                testURI.m_host))) && m_port == testURI.m_port && ((m_path == null && testURI.m_path == null) || (m_path != null && testURI.m_path != null && m_path.equals(
                testURI.m_path))) && ((m_queryString == null && testURI.m_queryString == null) || (m_queryString != null && testURI.m_queryString != null && m_queryString.equals(
                testURI.m_queryString))) && ((m_fragment == null && testURI.m_fragment == null) || (m_fragment != null && testURI.m_fragment != null && m_fragment.equals(
                testURI.m_fragment))))
        {
          return true;
        }
      }
  
      return false;
    }
  
    @Override
    public int hashCode() {
      int hash = 5;
      hash = 41 * hash + Objects.hashCode(this.m_scheme);
      hash = 41 * hash + Objects.hashCode(this.m_userinfo);
      hash = 41 * hash + Objects.hashCode(this.m_host);
      hash = 41 * hash + this.m_port;
      hash = 41 * hash + Objects.hashCode(this.m_path);
      hash = 41 * hash + Objects.hashCode(this.m_queryString);
      hash = 41 * hash + Objects.hashCode(this.m_fragment);
      return hash;
    }
  
    /**
     * Get the URI as a string specification. See RFC 2396 Section 5.2.
     *
     * @return the URI string specification
     */
    @Override
    public String toString()
    {
  
      final StringBuilder uriSpecString = new StringBuilder();
  
      if (m_scheme != null)
      {
        uriSpecString.append(m_scheme);
        uriSpecString.append(':');
      }
  
      uriSpecString.append(getSchemeSpecificPart());
  
      return uriSpecString.toString();
    }
  
    /**
     * Get the indicator as to whether this URI uses the "generic URI"
     * syntax.
     *
     * @return true if this URI uses the "generic URI" syntax, false
     *         otherwise
     */
    public boolean isGenericURI()
    {
  
      // presence of the host (whether valid or empty) means
      // double-slashes which means generic uri
      return (m_host != null);
    }
  
    /**
     * Determine whether a scheme conforms to the rules for a scheme name.
     * A scheme is conformant if it starts with an alphanumeric, and
     * contains only alphanumerics, '+','-' and '.'.
     *
     *
     * @param p_scheme The sheme name to check
     * @return true if the scheme is conformant, false otherwise
     */
    public static boolean isConformantSchemeName(String p_scheme)
    {
  
      if (p_scheme == null || p_scheme.trim().length() == 0)
      {
        return false;
      }
  
      if (!isAlpha(p_scheme.charAt(0)))
      {
        return false;
      }
  
      char testChar;
  
      for (int i = 1; i < p_scheme.length(); i++)
      {
        testChar = p_scheme.charAt(i);
  
        if (!isAlphanum(testChar) && SCHEME_CHARACTERS.indexOf(testChar) == -1)
        {
          return false;
        }
      }
  
      return true;
    }
  
    /**
     * Determine whether a string is syntactically capable of representing
     * a valid IPv4 address or the domain name of a network host. A valid
     * IPv4 address consists of four decimal digit groups separated by a
     * '.'. A hostname consists of domain labels (each of which must
     * begin and end with an alphanumeric but may contain '-') separated
     * & by a '.'. See RFC 2396 Section 3.2.2.
     *
     *
     * @param p_address The address string to check
     * @return true if the string is a syntactically valid IPv4 address
     *              or hostname
     */
    public static boolean isWellFormedAddress(String p_address)
    {
  
      if (p_address == null)
      {
        return false;
      }
  
      String address = p_address.trim();
      int addrLength = address.length();
  
      if (addrLength == 0 || addrLength > 255)
      {
        return false;
      }
  
      if (address.startsWith(".") || address.startsWith("-"))
      {
        return false;
      }
  
      // rightmost domain label starting with digit indicates IP address
      // since top level domain label can only start with an alpha
      // see RFC 2396 Section 3.2.2
      int index = address.lastIndexOf('.');
  
      if (address.endsWith("."))
      {
        index = address.substring(0, index).lastIndexOf('.');
      }
  
      if (index + 1 < addrLength && isDigit(p_address.charAt(index + 1)))
      {
        char testChar;
        int numDots = 0;
  
        // make sure that 1) we see only digits and dot separators, 2) that
        // any dot separator is preceded and followed by a digit and
        // 3) that we find 3 dots
        for (int i = 0; i < addrLength; i++)
        {
          testChar = address.charAt(i);
  
          if (testChar == '.')
          {
            if (!isDigit(address.charAt(i - 1))
                    || (i + 1 < addrLength &&!isDigit(address.charAt(i + 1))))
            {
              return false;
            }
  
            numDots++;
          }
          else if (!isDigit(testChar))
          {
            return false;
          }
        }
  
        if (numDots != 3)
        {
          return false;
        }
      }
      else
      {
  
        // domain labels can contain alphanumerics and '-"
        // but must start and end with an alphanumeric
        char testChar;
  
        for (int i = 0; i < addrLength; i++)
        {
          testChar = address.charAt(i);
  
          if (testChar == '.')
          {
            if (!isAlphanum(address.charAt(i - 1)))
            {
              return false;
            }
  
            if (i + 1 < addrLength &&!isAlphanum(address.charAt(i + 1)))
            {
              return false;
            }
          }
          else if (!isAlphanum(testChar) && testChar != '-')
          {
            return false;
          }
        }
      }
  
      return true;
    }
  
    /**
     * Determine whether a char is a digit.
     *
     *
     * @param p_char the character to check
     * @return true if the char is betweeen '0' and '9', false otherwise
     */
    private static boolean isDigit(char p_char)
    {
      return p_char >= '0' && p_char <= '9';
    }
  
    /**
     * Determine whether a character is a hexadecimal character.
     *
     *
     * @param p_char the character to check
     * @return true if the char is between '0' and '9', 'a' and 'f'
     *         or 'A' and 'F', false otherwise
     */
    private static boolean isHex(char p_char)
    {
      return (isDigit(p_char) || (p_char >= 'a' && p_char <= 'f')
              || (p_char >= 'A' && p_char <= 'F'));
    }
  
    /**
     * Determine whether a char is an alphabetic character: a-z or A-Z
     *
     *
     * @param p_char the character to check
     * @return true if the char is alphabetic, false otherwise
     */
    private static boolean isAlpha(char p_char)
    {
      return ((p_char >= 'a' && p_char <= 'z')
              || (p_char >= 'A' && p_char <= 'Z'));
    }
  
    /**
     * Determine whether a char is an alphanumeric: 0-9, a-z or A-Z
     *
     *
     * @param p_char the character to check
     * @return true if the char is alphanumeric, false otherwise
     */
    private static boolean isAlphanum(char p_char)
    {
      return (isAlpha(p_char) || isDigit(p_char));
    }
  
    /**
     * Determine whether a character is a reserved character:
     * ';', '/', '?', ':', '@', '&', '=', '+', '$' or ','
     *
     *
     * @param p_char the character to check
     * @return true if the string contains any reserved characters
     */
    private static boolean isReservedCharacter(char p_char)
    {
      return RESERVED_CHARACTERS.indexOf(p_char) != -1;
    }
  
    /**
     * Determine whether a char is an unreserved character.
     *
     *
     * @param p_char the character to check
     * @return true if the char is unreserved, false otherwise
     */
    private static boolean isUnreservedCharacter(char p_char)
    {
      return (isAlphanum(p_char) || MARK_CHARACTERS.indexOf(p_char) != -1);
    }
  
    /**
     * Determine whether a given string contains only URI characters (also
     * called "uric" in RFC 2396). uric consist of all reserved
     * characters, unreserved characters and escaped characters.
     *
     *
     * @param p_uric URI string
     * @return true if the string is comprised of uric, false otherwise
     */
    private static boolean isURIString(String p_uric)
    {
  
      if (p_uric == null)
      {
        return false;
      }
  
      int end = p_uric.length();
      char testChar = '\0';
  
      for (int i = 0; i < end; i++)
      {
        testChar = p_uric.charAt(i);
  
        if (testChar == '%')
        {
          if (i + 2 >= end ||!isHex(p_uric.charAt(i + 1))
                  ||!isHex(p_uric.charAt(i + 2)))
          {
            return false;
          }
          else
          {
            i += 2;
  
            continue;
          }
        }
  
        if (isReservedCharacter(testChar) || isUnreservedCharacter(testChar))
        {
          continue;
        }
        else
        {
          return false;
        }
      }
  
      return true;
    }
  }
  