Source code: org/apache/axis/types/URI.java

   /*
    * 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.
   */
  
  package org.apache.axis.types;
  
  import java.io.IOException;
  import java.io.Serializable;
  
  /**********************************************************************
  * <i>Axis Note: This class was 'borrowed' from Xerces 2:
   * org.apache.xerces.util.URI.java, version 1.22 </i>
  * <p>
  * 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 
  * <a href="http://www.ietf.org/rfc/rfc2396.txt?number=2396">RFC 2396</a>,
  * and amended by
  * <a href="http://www.ietf.org/rfc/rfc2732.txt?number=2732">RFC 2732</a>. 
  * <p>
  * Every absolute 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 {
  
    /*******************************************************************
    * 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 {
  
     /** Serialization version. */
     static final long serialVersionUID = -6695054834342951930L;
     
     /******************************************************************
      * 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);
      }
    }
  
    /** Serialization version. */
    static final long serialVersionUID = 1601921774685357214L;
  
    private static final byte [] fgLookupTable = new byte[128];
    
    /**
     * Character Classes
     */
    
    /** reserved characters ;/?:@&=+$,[] */
   //RFC 2732 added '[' and ']' as reserved characters
   private static final int RESERVED_CHARACTERS = 0x01;
   
   /** URI punctuation mark characters: -_.!~*'() - these, combined with
       alphanumerics, constitute the "unreserved" characters */
   private static final int MARK_CHARACTERS = 0x02;
   
   /** scheme can be composed of alphanumerics and these characters: +-. */
   private static final int SCHEME_CHARACTERS = 0x04;
   
   /** userinfo can be composed of unreserved, escaped and these
       characters: ;:&=+$, */
   private static final int USERINFO_CHARACTERS = 0x08;
   
   /** ASCII letter characters */
   private static final int ASCII_ALPHA_CHARACTERS = 0x10;
   
   /** ASCII digit characters */
   private static final int ASCII_DIGIT_CHARACTERS = 0x20;
   
   /** ASCII hex characters */
   private static final int ASCII_HEX_CHARACTERS = 0x40;
   
   /** Path characters */
   private static final int PATH_CHARACTERS = 0x80;
 
   /** Mask for alpha-numeric characters */
   private static final int MASK_ALPHA_NUMERIC = ASCII_ALPHA_CHARACTERS | ASCII_DIGIT_CHARACTERS;
   
   /** Mask for unreserved characters */
   private static final int MASK_UNRESERVED_MASK = MASK_ALPHA_NUMERIC | MARK_CHARACTERS;
   
   /** Mask for URI allowable characters except for % */
   private static final int MASK_URI_CHARACTER = MASK_UNRESERVED_MASK | RESERVED_CHARACTERS;
   
   /** Mask for scheme characters */
   private static final int MASK_SCHEME_CHARACTER = MASK_ALPHA_NUMERIC | SCHEME_CHARACTERS;
   
   /** Mask for userinfo characters */
   private static final int MASK_USERINFO_CHARACTER = MASK_UNRESERVED_MASK | USERINFO_CHARACTERS;
   
   /** Mask for path characters */
   private static final int MASK_PATH_CHARACTER = MASK_UNRESERVED_MASK | PATH_CHARACTERS; 
 
   static {
       // Add ASCII Digits and ASCII Hex Numbers
       for (int i = '0'; i <= '9'; ++i) {
           fgLookupTable[i] |= ASCII_DIGIT_CHARACTERS | ASCII_HEX_CHARACTERS;
       }
 
       // Add ASCII Letters and ASCII Hex Numbers
       for (int i = 'A'; i <= 'F'; ++i) {
           fgLookupTable[i] |= ASCII_ALPHA_CHARACTERS | ASCII_HEX_CHARACTERS;
           fgLookupTable[i+0x00000020] |= ASCII_ALPHA_CHARACTERS | ASCII_HEX_CHARACTERS;
       }
 
       // Add ASCII Letters
       for (int i = 'G'; i <= 'Z'; ++i) {
           fgLookupTable[i] |= ASCII_ALPHA_CHARACTERS;
           fgLookupTable[i+0x00000020] |= ASCII_ALPHA_CHARACTERS;
       }
 
       // Add Reserved Characters
       fgLookupTable[';'] |= RESERVED_CHARACTERS;
       fgLookupTable['/'] |= RESERVED_CHARACTERS;
       fgLookupTable['?'] |= RESERVED_CHARACTERS;
       fgLookupTable[':'] |= RESERVED_CHARACTERS;
       fgLookupTable['@'] |= RESERVED_CHARACTERS;
       fgLookupTable['&'] |= RESERVED_CHARACTERS;
       fgLookupTable['='] |= RESERVED_CHARACTERS;
       fgLookupTable['+'] |= RESERVED_CHARACTERS;
       fgLookupTable['$'] |= RESERVED_CHARACTERS;
       fgLookupTable[','] |= RESERVED_CHARACTERS;
       fgLookupTable['['] |= RESERVED_CHARACTERS;
       fgLookupTable[']'] |= RESERVED_CHARACTERS;
 
       // Add Mark Characters
       fgLookupTable['-'] |= MARK_CHARACTERS;
       fgLookupTable['_'] |= MARK_CHARACTERS;
       fgLookupTable['.'] |= MARK_CHARACTERS;
       fgLookupTable['!'] |= MARK_CHARACTERS;
       fgLookupTable['~'] |= MARK_CHARACTERS;
       fgLookupTable['*'] |= MARK_CHARACTERS;
       fgLookupTable['\''] |= MARK_CHARACTERS;
       fgLookupTable['('] |= MARK_CHARACTERS;
       fgLookupTable[')'] |= MARK_CHARACTERS;
 
       // Add Scheme Characters
       fgLookupTable['+'] |= SCHEME_CHARACTERS;
       fgLookupTable['-'] |= SCHEME_CHARACTERS;
       fgLookupTable['.'] |= SCHEME_CHARACTERS;
 
       // Add Userinfo Characters
       fgLookupTable[';'] |= USERINFO_CHARACTERS;
       fgLookupTable[':'] |= USERINFO_CHARACTERS;
       fgLookupTable['&'] |= USERINFO_CHARACTERS;
       fgLookupTable['='] |= USERINFO_CHARACTERS;
       fgLookupTable['+'] |= USERINFO_CHARACTERS;
       fgLookupTable['$'] |= USERINFO_CHARACTERS;
       fgLookupTable[','] |= USERINFO_CHARACTERS;
       
       // Add Path Characters
       fgLookupTable[';'] |= PATH_CHARACTERS;
       fgLookupTable['/'] |= PATH_CHARACTERS;
       fgLookupTable[':'] |= PATH_CHARACTERS;
       fgLookupTable['@'] |= PATH_CHARACTERS;
       fgLookupTable['&'] |= PATH_CHARACTERS;
       fgLookupTable['='] |= PATH_CHARACTERS;
       fgLookupTable['+'] |= PATH_CHARACTERS;
       fgLookupTable['$'] |= PATH_CHARACTERS;
       fgLookupTable[','] |= PATH_CHARACTERS;
   }
 
   /** Stores the scheme (usually the protocol) for this URI. */
   private String m_scheme = null;
 
   /** If specified, stores the userinfo for this URI; otherwise null */
   private String m_userinfo = null;
 
   /** If specified, stores the host for this URI; otherwise null */
   private String m_host = null;
 
   /** If specified, stores the port for this URI; otherwise -1 */
   private int m_port = -1;
   
   /** If specified, stores the registry based authority for this URI; otherwise -1 */
   private String m_regAuthority = null;
 
   /** If specified, stores the path for this URI; otherwise null */
   private String m_path = null;
 
   /** If specified, stores the query string for this URI; otherwise
       null.  */
   private String m_queryString = null;
 
   /** If specified, stores the fragment for this URI; otherwise null */
   private String m_fragment = null;
 
   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)
   *
   * @exception 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 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.
    * Construct a relative URI if boolean is assigned to "true"
    * and p_uriSpec is not valid absolute URI, instead of throwing an exception. 
    * 
    * @param p_uriSpec the URI specification string (cannot be null or
    *                  empty)
    * @param allowNonAbsoluteURI true to permit non-absolute URIs, 
    *                            false otherwise.
    *
    * @exception MalformedURIException if p_uriSpec violates any syntax
    *                                   rules
    */
   public URI(String p_uriSpec, boolean allowNonAbsoluteURI) throws MalformedURIException {
       this((URI)null, p_uriSpec, allowNonAbsoluteURI);
   }
   
  /**
   * 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)
   *
   * @exception 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 from a base URI and a URI specification string.
    * The URI specification string may be a relative URI.
    * Construct a relative URI if boolean is assigned to "true"
    * and p_uriSpec is not valid absolute URI and p_base is null
    * instead of throwing an exception. 
    *
    * @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)
    * @param allowNonAbsoluteURI true to permit non-absolute URIs, 
    *                            false otherwise.
    *
    * @exception MalformedURIException if p_uriSpec violates any syntax
    *                                  rules
    */
   public URI(URI p_base, String p_uriSpec, boolean allowNonAbsoluteURI) throws MalformedURIException {
       initialize(p_base, p_uriSpec, allowNonAbsoluteURI);
   }
 
  /**
   * 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)
   *
   * @exception 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, IPv4 address or IPv6 reference 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)
   *
   * @exception 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, IPv4 address or IPv6 reference 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)
   *
   * @exception 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("Scheme is required!");
     }
 
     if (p_host == null) {
       if (p_userinfo != null) {
         throw new MalformedURIException(
              "Userinfo may not be specified if host is not specified!");
       }
       if (p_port != -1) {
         throw new MalformedURIException(
              "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(
           "Query string cannot be specified in path and query string!");
       }
 
       if (p_path.indexOf('#') != -1 && p_fragment != null) {
         throw new MalformedURIException(
           "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_regAuthority = p_other.getRegBasedAuthority();
     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)
    * @param allowNonAbsoluteURI true to permit non-absolute URIs, 
    *                         in case of relative URI, false otherwise.
    *
    * @exception 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, boolean allowNonAbsoluteURI)
       throws MalformedURIException {
       
       String uriSpec = p_uriSpec;
       int uriSpecLen = (uriSpec != null) ? uriSpec.length() : 0;
       
       if (p_base == null && uriSpecLen == 0) {
           if (allowNonAbsoluteURI) {
               m_path = "";
               return;
           }
           throw new MalformedURIException("Cannot initialize URI with empty parameters.");
       }
       
       // just make a copy of the base if spec is empty
       if (uriSpecLen == 0) {
           initialize(p_base);
           return;
       }
       
       int index = 0;
       
       // Check for scheme, which must be before '/', '?' or '#'.
       int colonIdx = uriSpec.indexOf(':');
       if (colonIdx != -1) {
           final int searchFrom = colonIdx - 1;
           // search backwards starting from character before ':'.
           int slashIdx = uriSpec.lastIndexOf('/', searchFrom);
           int queryIdx = uriSpec.lastIndexOf('?', searchFrom);
           int fragmentIdx = uriSpec.lastIndexOf('#', searchFrom);
           
           if (colonIdx == 0 || slashIdx != -1 || 
               queryIdx != -1 || fragmentIdx != -1) {
               // A standalone base is a valid URI according to spec
               if (colonIdx == 0 || (p_base == null && fragmentIdx != 0 && !allowNonAbsoluteURI)) {
                   throw new MalformedURIException("No scheme found in URI.");
               }
           }
           else {
               initializeScheme(uriSpec);
               index = m_scheme.length()+1;
               
               // Neither 'scheme:' or 'scheme:#fragment' are valid URIs.
               if (colonIdx == uriSpecLen - 1 || uriSpec.charAt(colonIdx+1) == '#') {
                   throw new MalformedURIException("Scheme specific part cannot be empty.");   
               }
           }
       }
       else if (p_base == null && uriSpec.indexOf('#') != 0 && !allowNonAbsoluteURI) {
           throw new MalformedURIException("No scheme found in URI.");    
       }
       
       // Two slashes means we may have authority, but definitely means we're either
       // matching net_path or abs_path. These two productions are ambiguous in that
       // every net_path (except those containing an IPv6Reference) is an abs_path. 
       // RFC 2396 resolves this ambiguity by applying a greedy left most matching rule. 
       // Try matching net_path first, and if that fails we don't have authority so 
       // then attempt to match abs_path.
       //
       // net_path = "//" authority [ abs_path ]
       // abs_path = "/"  path_segments
       if (((index+1) < uriSpecLen) &&
           (uriSpec.charAt(index) == '/' && uriSpec.charAt(index+1) == '/')) {
           index += 2;
           int startPos = index;
           
           // Authority will be everything up to path, query or fragment
           char testChar = '\0';
           while (index < uriSpecLen) {
               testChar = uriSpec.charAt(index);
               if (testChar == '/' || testChar == '?' || testChar == '#') {
                   break;
               }
               index++;
           }
           
           // Attempt to parse authority. If the section is an empty string
           // this is a valid server based authority, so set the host to this
           // value.
           if (index > startPos) {
               // If we didn't find authority we need to back up. Attempt to
               // match against abs_path next.
               if (!initializeAuthority(uriSpec.substring(startPos, index))) {
                   index = startPos - 2;
               }
           }
           else {
               m_host = "";
           }
       }
       
       initializePath(uriSpec, 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) {
           absolutize(p_base);
       }
   }
 
  /**
   * 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)
   *
   * @exception 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 {
       
     String uriSpec = p_uriSpec;
     int uriSpecLen = (uriSpec != null) ? uriSpec.length() : 0;
     
     if (p_base == null && uriSpecLen == 0) {
       throw new MalformedURIException(
                   "Cannot initialize URI with empty parameters.");
     }
 
     // just make a copy of the base if spec is empty
     if (uriSpecLen == 0) {
       initialize(p_base);
       return;
     }
 
     int index = 0;
 
     // Check for scheme, which must be before '/', '?' or '#'.
     int colonIdx = uriSpec.indexOf(':');
     if (colonIdx != -1) {
         final int searchFrom = colonIdx - 1;
         // search backwards starting from character before ':'.
         int slashIdx = uriSpec.lastIndexOf('/', searchFrom);
         int queryIdx = uriSpec.lastIndexOf('?', searchFrom);
         int fragmentIdx = uriSpec.lastIndexOf('#', searchFrom);
        
         if (colonIdx == 0 || slashIdx != -1 || 
             queryIdx != -1 || fragmentIdx != -1) {
             // A standalone base is a valid URI according to spec
             if (colonIdx == 0 || (p_base == null && fragmentIdx != 0)) {
                 throw new MalformedURIException("No scheme found in URI.");
             }
         }
         else {
             initializeScheme(uriSpec);
             index = m_scheme.length()+1;
             
             // Neither 'scheme:' or 'scheme:#fragment' are valid URIs.
             if (colonIdx == uriSpecLen - 1 || uriSpec.charAt(colonIdx+1) == '#') {
                 throw new MalformedURIException("Scheme specific part cannot be empty.");    
             }
         }
     }
     else if (p_base == null && uriSpec.indexOf('#') != 0) {
         throw new MalformedURIException("No scheme found in URI.");    
     }
 
     // Two slashes means we may have authority, but definitely means we're either
     // matching net_path or abs_path. These two productions are ambiguous in that
     // every net_path (except those containing an IPv6Reference) is an abs_path. 
     // RFC 2396 resolves this ambiguity by applying a greedy left most matching rule. 
     // Try matching net_path first, and if that fails we don't have authority so 
     // then attempt to match abs_path.
     //
     // net_path = "//" authority [ abs_path ]
     // abs_path = "/"  path_segments
     if (((index+1) < uriSpecLen) &&
         (uriSpec.charAt(index) == '/' && uriSpec.charAt(index+1) == '/')) {
       index += 2;
       int startPos = index;
 
       // Authority will be everything up to path, query or fragment
       char testChar = '\0';
       while (index < uriSpecLen) {
         testChar = uriSpec.charAt(index);
         if (testChar == '/' || testChar == '?' || testChar == '#') {
           break;
         }
         index++;
       }
 
       // Attempt to parse authority. If the section is an empty string
       // this is a valid server based authority, so set the host to this
       // value.
       if (index > startPos) {
         // If we didn't find authority we need to back up. Attempt to
         // match against abs_path next.
         if (!initializeAuthority(uriSpec.substring(startPos, index))) {
           index = startPos - 2;
         }
       }
       else {
         m_host = "";
       }
     }
 
     initializePath(uriSpec, 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) {
         absolutize(p_base);
     }
   }
 
   /**
    * Absolutize URI with given base URI.
    *
    * @param p_base base URI for absolutization
    */
   public void absolutize(URI p_base) {
 
       // 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_regAuthority == null) {
         m_scheme = p_base.getScheme();
         m_userinfo = p_base.getUserinfo();
         m_host = p_base.getHost();
         m_port = p_base.getPort();
         m_regAuthority = p_base.getRegBasedAuthority();
         m_path = p_base.getPath();
 
         if (m_queryString == null) {
           m_queryString = p_base.getQueryString();
               
               if (m_fragment == null) {
                   m_fragment = p_base.getFragment();
               }
         }
         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();
       }
       else {
         return;
       }
 
       // 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_regAuthority == null) {
         m_userinfo = p_base.getUserinfo();
         m_host = p_base.getHost();
         m_port = p_base.getPort();
         m_regAuthority = p_base.getRegBasedAuthority();
       }
       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 && basePath.length() > 0) {
         int lastSlash = basePath.lastIndexOf('/');
         if (lastSlash != -1) {
           path = basePath.substring(0, lastSlash+1);
         }
       }
       else if (m_path.length() > 0) {
           path = "/";
       }
 
       // 6b - append the relative URI path
       path = path.concat(m_path);
 
       // 6c - remove all "./" where "." is a complete path segment
       int 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("/../", index)) > 0) {
         tempString = path.substring(0, path.indexOf("/../"));
         segIndex = tempString.lastIndexOf('/');
         if (segIndex != -1) {
           if (!tempString.substring(segIndex).equals("..")) {
             path = path.substring(0, segIndex+1).concat(path.substring(index+4));
             index = segIndex;
           }
               else {
             index += 4;
         }
           }
           else {
           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)
   *
   * @exception 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("No scheme found in URI.");
     }
     else {
       setScheme(scheme);
     }
   }
 
  /**
   * Initialize the authority (either server or registry based)
   * for this URI from a URI string spec.
   *
   * @param p_uriSpec the URI specification (cannot be null)
   * 
   * @return true if the given string matched server or registry
   * based authority
   */
   private boolean initializeAuthority(String p_uriSpec) {
     
     int index = 0;
     int start = 0;
     int end = p_uriSpec.length();
 
     char testChar = '\0';
     String userinfo = null;
 
     // userinfo is everything up to @
     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 last ':', or up to 
     // and including ']' if followed by ':'.
     String host = null;
     start = index;
     boolean hasPort = false;
     if (index < end) {
       if (p_uriSpec.charAt(start) == '[') {
           int bracketIndex = p_uriSpec.indexOf(']', start);
           index = (bracketIndex != -1) ? bracketIndex : end;
           if (index+1 < end && p_uriSpec.charAt(index+1) == ':') {
             ++index;
             hasPort = true;
           }
           else {
             index = end;
           }
       }
       else {
           int colonIndex = p_uriSpec.lastIndexOf(':', end);
           index = (colonIndex > start) ? colonIndex : end;
           hasPort = (index != end);
       }
     }
     host = p_uriSpec.substring(start, index);
     int port = -1;
     if (host.length() > 0) {
       // port
       if (hasPort) {
         index++;
         start = index;
         while (index < end) {
           index++;
         }
         String portStr = p_uriSpec.substring(start, index);
         if (portStr.length() > 0) {
           // REVISIT: Remove this code.
           /** for (int i = 0; i < portStr.length(); i++) {
             if (!isDigit(portStr.charAt(i))) {
               throw new MalformedURIException(
                    portStr +
                    " is invalid. Port should only contain digits!");
             }
           }**/
           // REVISIT: Remove this code.
           // Store port value as string instead of integer.
           try {
             port = Integer.parseInt(portStr);
             if (port == -1) --port;
           }
           catch (NumberFormatException nfe) {
             port = -2;
           }
         }
       }
     }
     
     if (isValidServerBasedAuthority(host, port, userinfo)) {
       m_host = host;
       m_port = port;
       m_userinfo = userinfo;
       return true;
     }
     // Note: Registry based authority is being removed from a
     // new spec for URI which would obsolete RFC 2396. If the
     // spec is added to XML errata, processing of reg_name
     // needs to be removed. - mrglavas.
     else if (isValidRegistryBasedAuthority(p_uriSpec)) {
       m_regAuthority = p_uriSpec;
       return true;
     }
     return false;
   }
   
   /**
    * Determines whether the components host, port, and user info
    * are valid as a server authority.
    * 
    * @param host the host component of authority
    * @param port the port number component of authority
    * @param userinfo the user info component of authority
    * 
    * @return true if the given host, port, and userinfo compose
    * a valid server authority
    */
   private boolean isValidServerBasedAuthority(String host, int port, String userinfo) {
     
     // Check if the host is well formed.
     if (!isWellFormedAddress(host)) {
       return false;
     }
     
     // Check that port is well formed if it exists.
     // REVISIT: There's no restriction on port value ranges, but
     // perform the same check as in setPort to be consistent. Pass
     // in a string to this method instead of an integer.
     if (port < -1 || port > 65535) {
       return false;
     }
     
     // Check that userinfo is well formed if it exists.
     if (userinfo != null) {
       // Userinfo can contain alphanumerics, mark characters, escaped
       // and ';',':','&','=','+','$',','
       int index = 0;
      int end = userinfo.length();
      char testChar = '\0';
      while (index < end) {
        testChar = userinfo.charAt(index);
        if (testChar == '%') {
          if (index+2 >= end ||
            !isHex(userinfo.charAt(index+1)) ||
            !isHex(userinfo.charAt(index+2))) {
            return false;
          }
          index += 2;
        }
        else if (!isUserinfoCharacter(testChar)) {
          return false;
        }
        ++index;
      }
    }
    return true;
  }
  
  /**
   * Determines whether the given string is a registry based authority.
   * 
   * @param authority the authority component of a URI
   * 
   * @return true if the given string is a registry based authority
   */
  private boolean isValidRegistryBasedAuthority(String authority) {
    int index = 0;
    int end = authority.length();
    char testChar;
      
    while (index < end) {
      testChar = authority.charAt(index);
      
      // check for valid escape sequence
      if (testChar == '%') {
        if (index+2 >= end ||
            !isHex(authority.charAt(index+1)) ||
            !isHex(authority.charAt(index+2))) {
            return false;
        }
        index += 2;
      }
      // can check against path characters because the set
      // is the same except for '/' which we've already excluded.
      else if (!isPathCharacter(testChar)) {
        return false;
      }
      ++index;
    }
    return true;
  }
      
 /**
  * Initialize the path for this URI from a URI string spec.
  *
  * @param p_uriSpec the URI specification (cannot be null)
  * @param p_nStartIndex the index to begin scanning from
  *
  * @exception MalformedURIException if p_uriSpec violates syntax rules
  */
  private void initializePath(String p_uriSpec, int p_nStartIndex)
                 throws MalformedURIException {
    if (p_uriSpec == null) {
      throw new MalformedURIException(
                "Cannot initialize path from null string!");
    }

    int index = p_nStartIndex;
    int start = p_nStartIndex;
    int end = p_uriSpec.length();
    char testChar = '\0';

    // path - everything up to query string or fragment
    if (start < end) {
        // RFC 2732 only allows '[' and ']' to appear in the opaque part.
        if (getScheme() == null || p_uriSpec.charAt(start) == '/') {
        
            // Scan path.
            // abs_path = "/"  path_segments
            // rel_path = rel_segment [ abs_path ]
            while (index < end) {
                testChar = p_uriSpec.charAt(index);
            
                // 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(
                            "Path contains invalid escape sequence!");
                    }
                    index += 2;
                }
                // Path segments cannot contain '[' or ']' since pchar
                // production was not changed by RFC 2732.
                else if (!isPathCharacter(testChar)) {
                      if (testChar == '?' || testChar == '#') {
                          break;
                      }
                    throw new MalformedURIException(
                        "Path contains invalid character: " + testChar);
                }
                ++index;
            }
        }
        else {
            
            // Scan opaque part.
            // opaque_part = uric_no_slash *uric
            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(
                            "Opaque part contains invalid escape sequence!");
                    }
                    index += 2;
                }
                // If the scheme specific part is opaque, it can contain '['
                // and ']'. uric_no_slash wasn't modified by RFC 2732, which
                // I've interpreted as an error in the spec, since the 
                // production should be equivalent to (uric - '/'), and uric
                // contains '[' and ']'. - mrglavas
                else if (!isURICharacter(testChar)) {
                    throw new MalformedURIException(
                        "Opaque part 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!");
           }
           index += 2;
        }
        else if (!isURICharacter(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!");
           }
           index += 2;
        }
        else if (!isURICharacter(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() {
    StringBuffer schemespec = new StringBuffer();

    if (m_host != null || m_regAuthority != null) {
      schemespec.append("//");
    
      // Server based authority.
      if (m_host != null) {

        if (m_userinfo != null) {
          schemespec.append(m_userinfo);
          schemespec.append('@');
        }
        
        schemespec.append(m_host);
        
        if (m_port != -1) {
          schemespec.append(':');
          schemespec.append(m_port);
        }
      }
      // Registry based authority.
      else {
          schemespec.append(m_regAuthority);
      }
    }

    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 registry based authority for this URI.
   * 
   * @return the registry based authority (null if not specified).
   */
  public String getRegBasedAuthority() {
    return m_regAuthority;
  }

 /**
  * 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) {
    StringBuffer pathString = new StringBuffer(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)
  *
  * @exception 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(
                "Cannot set scheme from null string!");
    }
    if (!isConformantSchemeName(p_scheme)) {
      throw new MalformedURIException("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
  *
  * @exception MalformedURIException if p_userinfo contains invalid
  *                                  characters
  */
  public void setUserinfo(String p_userinfo) throws MalformedURIException {
    if (p_userinfo == null) {
      m_userinfo = null;
      return;
    }
    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 (!isUserinfoCharacter(testChar)) {
          throw new MalformedURIException(
                  "Userinfo contains invalid character:"+testChar);
        }
        index++;
      }
    }
    m_userinfo = p_userinfo;
  }

 /**
  * <p>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.</p>
  * 
  * <p>Note: This method overwrites registry based authority if it
  * previously existed in this URI.</p>
  *
  * @param p_host the host for this URI
  *
  * @exception 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.length() == 0) {
      if (p_host != null) {
        m_regAuthority = null;
      }
      m_host = p_host;
      m_userinfo = null;
      m_port = -1;
      return;
    }
    else if (!isWellFormedAddress(p_host)) {
      throw new MalformedURIException("Host is not a well formed address!");
    }
    m_host = p_host;
    m_regAuthority = null;
  }

 /**
  * 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