001    /*
002     * file StpLocation.java
003     *
004     * Licensed Materials - Property of IBM
005     * Restricted Materials of IBM 
006     *
007     * com.ibm.rational.wvcm.stp.StpLocation
008     *
009     * (C) Copyright IBM Corporation 2004, 2010.  All Rights Reserved.
010     * Note to U.S. Government Users Restricted Rights:  Use, duplication or 
011     * disclosure restricted by GSA ADP  Schedule Contract with IBM Corp.
012     */
013    
014    package com.ibm.rational.wvcm.stp;
015    
016    import java.io.File;
017    import java.io.Serializable;
018    import java.net.MalformedURLException;
019    import java.util.EnumSet;
020    import java.util.Hashtable;
021    import java.util.Map;
022    
023    import javax.wvcm.Location;
024    import javax.wvcm.Resource;
025    import javax.wvcm.WvcmException;
026    
027    import com.ibm.rational.wvcm.stpex.StpExEnumeration;
028    import com.ibm.rational.wvcm.stpex.annotation.RpcEnum;
029    
030    /**
031     * An extension of the javax.wvcm Location interface that provides a
032     * programmatic representation for the location of a resource.
033     * 
034     * <p>
035     * An StpLocation instance represents a location specification that has been
036     * parsed into its various component fields. A number of different formats or
037     * <i>schemes</i> are used to express the location of various resources as a
038     * string. These schemes consist of one or more of the following fields:
039     * <i>domain</i>, <i>repository name</i>, <i>namespace</i>, and <i>object
040     * name</i>. It is the namespace field that determines the scheme being used.
041     * <p>
042     * Locations are hierarchical, with the domain field specifying the top level of
043     * the hierarchy. Within a domain, resources are partitioned into repositories.
044     * Within a repository, resources are first partitioned into namespaces, and
045     * then uniquely identified by segmented pathnames within that namespace.
046     * <p>
047     * Each scheme requires certain of the above fields to be specified. If required
048     * fields are not present, the StpLocation object will have a non-OK Status.
049     * Individual field values can be queried to determine which fields aren't
050     * present.
051     * <p>
052     * To use this StpLocation to construct a proxy, its Status must be OK.
053     * <p>
054     * When a proxy is constructed, a new StpLocation may need to be constructed, so
055     * clients must not assume that the object returned by Resource.location()
056     * or any of the StpLocation factory methods defined in StpProvider is
057     * the same object passed to the proxy factory that created the proxy.
058     * <p>
059     * The preferred scheme for specifying an object is the <i>object selector
060     * scheme</i>, which has the following structure
061     * <p> [[<i>&lt;domain></i>.][<i>&lt;namespace></i>]:] [<i>&lt;object-name></i>][&#64;[<i>&lt;repository-name></i>]]
062     * <p>
063     * The <i>&lt;object-name></i>, and <i>&lt;repository-name></i> fields are
064     * segmented names where the segments are separated by '/'s or '\'s. The
065     * permitted <i>&lt;namespace></i>s are defined by
066     * {@link StpLocation.Namespace} and the permitted <i>&lt;domain></i>s are
067     * defined by {@link StpProvider.Domain}.
068     * <p>
069     * The character '&#64;' is reserved for use as the repository field delimiter
070     * as defined above. If it is to be part of the name field, it must be escaped
071     * by preceding it with a percent sign '%'. Similarly, the characters '/' and
072     * '\' are reserved in both the name and repository fields to be used as
073     * pathname segment separators. To use them as part of a segment they, too, must
074     * be escaped using a percent sign. Use two percent signs, '%%', to include a
075     * percent sign in the name or repository field. Note that escaped characters
076     * within a field are <i>not</i> unescaped when parsed into a StpLocation.
077     * Utility methods are provided by the StpProvider class for unescaping the
078     * fields, should a client need the unadulterated image.
079     * <p>
080     * Some resources can also be referenced directly or indirectly by an absolute or
081     * relative file system pathname. As an StpLocation image, such
082     * representations are called <i>path-scheme</i> locations, which have the
083     * following structure
084     * <p> [[<i>&lt;domain></i>.][<i>&lt;namespace></i>]:] [<i>&lt;path-name></i>]
085     * <p>
086     * The path-scheme locations are further categorized by their namespace as
087     * indicated in this enumeration...
088     * <ul>
089     * <li>{@linkplain #isOk() <i>invalid</i>} namespaces: NONE, DEFAULT, INVALID,
090     * <li>{@linkplain #isFilePathScheme() <i>file path scheme</i>} namespaces:
091     * PNAME, PNAME_IMPLIED, FILE,
092     * <li>{@linkplain #isRepositoryPathScheme() <i>repository path scheme</i>}
093     * namespaces: VOB, VIEW_UUID, REPLICA_UUID, PROJ_DB, USER_DB, DB_SET, SERVER,
094     * <li>WORKSPACE,
095     * <li>{@linkplain #isUrlPathScheme() <i>URL path scheme</i>} namespaces: FILE,
096     * HTTP, HTTPS,
097     * </ul>
098     * This interface defines a predicate for each of these categories. The reader
099     * is referred to the documentation for those predicates for more information on
100     * the formation and meaning of each type of path-scheme location. Note that if
101     * a namespace is <i>not</i> one of the above path-scheme namespaces, it is an
102     * {@linkplain #isObjectSelectorScheme() <i>object selector scheme</i>}
103     * namespace.
104     * <p>
105     * %-escaping is not used in path-scheme locations.
106     */
107    public interface StpLocation extends javax.wvcm.Location
108    {
109        /**
110         * Returns the StpProvider object that created this StpLocation object
111         * 
112         * @return The StpProvider object that instantiated this instance of
113         *         StpLocation
114         */
115        StpProvider stpProvider();
116    
117        /**
118         * This class enumerates the namespaces that may appear in a location
119         * specification. Instances of the class are used to represent the namespace
120         * of the location represented by an StpLocation object.
121         * 
122         * The Namespace maps directly to the word token used in a location
123         * specification to denote the namespace of the resource named by the
124         * location. Each resource may appear in multiple namespaces.
125         */
126        public static enum Namespace implements StpExEnumeration, Serializable
127        {
128            /**
129             * A special path-scheme Namespace indicating that the namespace field
130             * of a location is unknown.
131             */
132            @RpcEnum(id=23, simpleName="INVALID")
133            INVALID("INVALID" /* NOI18N */),
134    
135            /**
136             * A special path-scheme Namespace indicating that no namespace was
137             * specified in the location specification.
138             */
139            @RpcEnum(id=26, simpleName="NONE")
140            NONE("NONE" /* NOI18N */),
141    
142            /**
143             * A special path-scheme Namespace indicating that the namespace field
144             * in the location specification was empty, which is the convention for
145             * specifying the default namespace of a repository.
146             */
147            @RpcEnum(id=8, simpleName="DEFAULT")
148            DEFAULT("DEFAULT" /* NOI18N */),
149    
150            /**
151             * The special, compound namespace used in stable selector schemes. To
152             * fully specify the stable selector scheme namespace, a resource-type
153             * string must follow the REPO word token in the location specification.
154             */
155            @RpcEnum(id=38, simpleName="repo")
156            REPO("repo" /* NOI18N */),
157    
158            /**
159             * The special, compound namespace used in the selector scheme for
160             * specification of efficiently-accessed locations. To fully specify the
161             * efficient selector scheme namespace, a resource-type string must
162             * follow the FAST word token in the location specification.
163             */
164            @RpcEnum(id=12, simpleName="fast")
165            FAST("fast" /* NOI18N */),
166    
167            /**
168             * A special file-path-scheme namespace that forces the rest of the
169             * location to be interpreted as a ClearCase P-name, a file system
170             * pathname with an optional history-mode extension.
171             */
172            @RpcEnum(id=28, simpleName="pname")
173            PNAME("pname" /* NOI18N */),
174    
175            /**
176             * A special file-path-scheme Namespace indicating a pname without an
177             * explicit PNAME prefix. Locations in the PNAME_IMPLIED namespace
178             * display simply as P-names.
179             */
180            @RpcEnum(id=29, simpleName="implicit")
181            PNAME_IMPLIED("implicit" /* NOI18N */),
182    
183            /**
184             * A repository-path-scheme Namespace for a ClearCase VOB specified
185             * directly by tag or indirectly by an entity within the VOB.
186             */
187            @RpcEnum(id=46, simpleName="vob")
188            VOB("vob" /* NOI18N */),
189    
190            /**
191             * A repository-path-scheme Namespace for a ClearCase VOB specified by
192             * its replica UUID
193             */
194            @RpcEnum(id=37, simpleName="replicauuid")
195            REPLICA_UUID("replicauuid" /* NOI18N */),
196    
197            /**
198             * A repository-path-scheme Namespace for a ClearCase VOB specified by
199             * its VOB family UUID.
200             */
201            @RpcEnum(id=51, simpleName="vobuuid")
202            VOB_UUID("vobuuid" /* NOI18N */),
203    
204            /**
205             * A repository-path-scheme Namespace for a ClearCase view specified by
206             * its UUID
207             */
208            @RpcEnum(id=45, simpleName="viewuuid")
209            VIEW_UUID("viewuuid" /* NOI18N */),
210    
211            /**
212             * A stable-selector-scheme Namespace for a ClearCase resource specified
213             * by its DBID
214             */
215            @RpcEnum(id=6, simpleName="dbid")
216            DBID("dbid" /* NOI18N */),
217    
218            /** A repository-path-scheme Namespace for a ClearQuest user database */
219            @RpcEnum(id=43, simpleName="userdb")
220            USER_DB("userdb" /* NOI18N */),
221    
222            /**
223             * A repository-path-scheme Namespace for a ClearQuest database known
224             * variously as a profile, connection, database-set, master database, or
225             * schema repository
226             */
227            @RpcEnum(id=7, simpleName="dbset")
228            DB_SET("dbset" /* NOI18N */),
229    
230            /**
231             * The user-friendly-selector-scheme Namespace for an action
232             */
233            @RpcEnum(id=0, simpleName="action")
234            ACTION("action" /* NOI18N */),
235    
236            /**
237             * The user-friendly-selector-scheme Namespace for an activity
238             */
239            @RpcEnum(id=1, simpleName="activity")
240            ACTIVITY("activity" /* NOI18N */),
241    
242            /**
243             * The user-friendly-selector-scheme Namespace for an attribute type
244             */
245            @RpcEnum(id=2, simpleName="attype")
246            ATTYPE("attype" /* NOI18N */),
247    
248            /** The user-friendly-selector-scheme Namespace for a baseline */
249            @RpcEnum(id=3, simpleName="baseline")
250            BASELINE("baseline" /* NOI18N */),
251    
252            /** The user-friendly-selector-scheme Namespace for a branch */
253            @RpcEnum(id=50, simpleName="branch")
254            BRANCH("branch" /* NOI18N */),
255    
256            /** The user-friendly-selector-scheme Namespace for a branch type */
257            @RpcEnum(id=4, simpleName="brtype")
258            BRTYPE("brtype" /* NOI18N */),
259    
260            /** The user-friendly-selector-scheme Namespace for a component */
261            @RpcEnum(id=5, simpleName="component")
262            COMPONENT("component" /* NOI18N */),
263    
264            /**
265             * The user-friendly-selector-scheme Namespace for a dynamic choice
266             * list.
267             */
268            @RpcEnum(id=10, simpleName="choicelist")
269            DYNAMIC_CHOICE_LIST("choicelist" /* NOI18N */),
270    
271            /** The user-friendly-selector-scheme Namespace for an element type */
272            @RpcEnum(id=11, simpleName="eltype")
273            ELTYPE("eltype" /* NOI18N */),
274    
275            /** The user-friendly-selector-scheme Namespace for a field definition */
276            @RpcEnum(id=13, simpleName="field")
277            FIELD_DEFINITION("field" /* NOI18N */),
278    
279            /** The URL-path-scheme and file-path-scheme Namespace for a file URL */
280            @RpcEnum(id=14, simpleName="file")
281            FILE("file" /* NOI18N */),
282    
283            /** The user-friendly-selector-scheme Namespace for a folder */
284            @RpcEnum(id=15, simpleName="folder")
285            FOLDER("folder" /* NOI18N */),
286    
287            /** The user-friendly-selector-scheme Namespace for a form */
288            @RpcEnum(id=16, simpleName="form")
289            FORM("form" /* NOI18N */),
290    
291            /** The user-friendly-selector-scheme Namespace for a group */
292            @RpcEnum(id=17, simpleName="group")
293            GROUP("group" /* NOI18N */),
294    
295            /** The user-friendly-selector-scheme Namespace for a hyperlink */
296            @RpcEnum(id=18, simpleName="hlink")
297            HLINK("hlink" /* NOI18N */),
298    
299            /** The user-friendly-selector-scheme Namespace for a hyperlink type */
300            @RpcEnum(id=19, simpleName="hltype")
301            HLTYPE("hltype" /* NOI18N */),
302    
303            /** The user-friendly-selector-scheme Namespace for a hook */
304            @RpcEnum(id=20, simpleName="hook")
305            HOOK("hook" /* NOI18N */),
306    
307            /** The user-friendly-selector-scheme Namespace for a label type */
308            @RpcEnum(id=24, simpleName="lbtype")
309            LBTYPE("lbtype" /* NOI18N */),
310    
311            /**
312             * A stable-selector-scheme Namespace for a ClearCase resource specified
313             * by its OID
314             */
315            @RpcEnum(id=27, simpleName="oid")
316            OID("oid" /* NOI18N */),
317            
318            /** The user-friendly-selector-scheme Namespace for a policy */
319            POLICY("policy" /* NOI18N */),
320    
321            /** The user-friendly-selector-scheme Namespace for a pool */
322            @RpcEnum(id=30, simpleName="pool")
323            POOL("pool" /* NOI18N */),
324    
325            /** The user-friendly-selector-scheme Namespace for a project. */
326            @RpcEnum(id=31, simpleName="project")
327            PROJECT("project" /* NOI18N */),
328    
329            /**
330             * The user-friendly-selector-scheme Namespace for a project
331             * configuration
332             */
333            @RpcEnum(id=32, simpleName="projconfig")
334            PROJECT_CONFIGURATION("projconfig" /* NOI18N */),
335    
336            /**
337             * The user-friendly-selector-scheme Namespace for a query, chart,
338             * report, report format, or query folder.
339             */
340            @RpcEnum(id=33, simpleName="query")
341            QUERY("query" /* NOI18N */),
342    
343            /**
344             * The user-friendly-selector-scheme Namespace for a record, record
345             * type, attachment folder, or attachment
346             */
347            @RpcEnum(id=34, simpleName="record")
348            RECORD("record" /* NOI18N */),
349    
350            /**
351             * The user-friendly, efficient, and stable-scheme Namespace for a
352             * ClearCase registry region.
353             */
354            @RpcEnum(id=35, simpleName="registryregion")
355            REGISTRY_REGION("registryregion" /* NOI18N */),
356    
357            /** The user-friendly-selector-scheme Namespace for a replica */
358            @RpcEnum(id=36, simpleName="replica")
359            REPLICA("replica" /* NOI18N */),
360            
361            /** The user-friendly-selector-scheme Namespace for a rolemap */
362            ROLEMAP("rolemap" /* NOI18N */),
363            
364            /** The user-friendly-selector-scheme Namespace for an rptype */
365            @RpcEnum(id=39, simpleName="rptype")
366            RPTYPE("rptype" /* NOI18N */),
367    
368            /**
369             * The user-friendly, efficient, and stable-scheme Namespace for a
370             * ClearCase storage location.
371             */
372            STORAGE_LOCATION("stgloc" /* NOI18N */),
373    
374            /** The user-friendly-selector-scheme Namespace for a stream */
375            @RpcEnum(id=40, simpleName="stream")
376            STREAM("stream" /* NOI18N */),
377    
378            /** The user-friendly-selector-scheme Namespace for a trigger type */
379            @RpcEnum(id=41, simpleName="trtype")
380            TRTYPE("trtype" /* NOI18N */),
381    
382            /**
383             * The URL-path-scheme Namespace denoting a location presented in the
384             * form of an HTTP URI or URL
385             */
386            @RpcEnum(id=21, simpleName="http")
387            HTTP("http" /* NOI18N */),
388    
389            /**
390             * The URL-path-scheme Namespace denoting a location presented in the
391             * form of an HTTPS URI or URL
392             */
393            @RpcEnum(id=22, simpleName="https")
394            HTTPS("https" /* NOI18N */),
395    
396            /** The user-friendly-selector-scheme Namespace for a user */
397            @RpcEnum(id=42, simpleName="user")
398            USER("user" /* NOI18N */),
399    
400            /**
401             * The user-friendly, efficient, and stable-scheme Namespace for a view
402             * tag.
403             */
404            @RpcEnum(id=44, simpleName="viewtag")
405            VIEWTAG("viewtag" /* NOI18N */),
406    
407            /**
408             * The user-friendly, efficient, and stable-scheme Namespace for a VOB
409             * tag.
410             */
411            @RpcEnum(id=47, simpleName="vobtag")
412            VOBTAG("vobtag" /* NOI18N */),
413    
414            /**
415             * The path-scheme Namespace for a ClearCase VOB tag, treated in some
416             * senses as a directory.
417             * 
418             * Note: This namespace is an implementation detail of the server, which
419             * unfortunately must be exposed to clients.
420             * 
421             * It is not intended that clients should attempt to create resources
422             * within this namespace.  Undefined behavior is guaranteed if clients
423             * attempt this.
424             * 
425             * It is not expected that the server will return resources within this
426             * namespace.
427             */
428            @RpcEnum(id=48, simpleName="vobtagasdirectory")
429            VOB_TAG_AS_DIRECTORY("vobtagasdirectory" /* NOI18N */),
430            
431            /** The path-scheme Namespace for a workspace */
432            @RpcEnum(id=49, simpleName="workspace")
433            WORKSPACE("workspace" /* NOI18N */),
434    
435            /**
436             * The user-friendly-selector-scheme Namespace for a server;
437             * e.g. ClearCase or ClearQuest
438             */
439            @RpcEnum(id=9, simpleName="domainserver")
440            DOMAINSERVER("server" /* NOI18N */),
441            
442            /** The path-scheme for a CCRC (aka, "legacy") server */
443            @RpcEnum(id=25, simpleName="legacyserver")
444            LEGACYSERVER("legacyserver" /* NOI18N */);
445    
446            /**
447             * Returns the word token for this Namespace in the namespace field of a
448             * location specification.
449             * 
450             * @return A String containing the namespace field value that denotes
451             *         this Namespace.
452             */
453            public String toNamespaceField()
454            {
455                return m_namespaceField;
456            }
457    
458            /**
459             * Finds the Namespace enumerator from the identifier used in the
460             * namespace field of a location specification.
461             * 
462             * @param field The word token as it appears in a location namespace
463             *            field.
464             * 
465             * @return The Namespace that the namespace field identifier denotes.
466             *         Namespace.INVALID is returned if no Namespace enumerator
467             *         matches the symbol exactly.
468             */
469            public static final Namespace fromNamespaceField(String field)
470            {
471                // Force to lower case before consulting symbol map
472                String symbol = field.toLowerCase();
473    
474                Namespace namespace = g_symbolToNamespaceMap.get(symbol);
475    
476                return namespace == null? Namespace.INVALID : namespace;
477            }
478    
479            /**
480             * EnumSet definitions for the various classifications of Namespaces
481             */
482            private static EnumSet<Namespace> invalid = EnumSet.of(INVALID, NONE);
483            private static EnumSet<Namespace> valid = EnumSet.complementOf(invalid);
484            private static EnumSet<Namespace> filePathSchemes =
485                EnumSet.of(PNAME,
486                           PNAME_IMPLIED,
487                           FILE);
488            private static EnumSet<Namespace> repositoryPathSchemes =
489                EnumSet.of(VOB,
490                           VIEW_UUID,
491                           REPLICA_UUID,
492                           USER_DB,
493                           DB_SET,
494                           LEGACYSERVER);
495            private static EnumSet<Namespace> urlPathSchemes = EnumSet.of(FILE,
496                                                                          HTTP,
497                                                                          HTTPS);
498            private static EnumSet<Namespace> pathSchemes =
499                union(EnumSet.of(WORKSPACE, NONE, DEFAULT, INVALID),
500                      filePathSchemes,
501                      urlPathSchemes,
502                      repositoryPathSchemes);
503            private static EnumSet<Namespace> escapeEncoded =
504                union(EnumSet.complementOf(union(pathSchemes, invalid)),
505                      EnumSet.of(USER_DB, DB_SET));
506            private static EnumSet<Namespace> extendedNamespaces =
507                EnumSet.of(REPO, FAST);
508    
509            /**
510             * Computes the union of a set of EnumSets
511             * 
512             * @param set Two or more EnumSet<Namespace> objects to be combined
513             *            into one.
514             * @return The logical union of the given EnumSets.
515             */
516            private static EnumSet<Namespace> union(EnumSet... set)
517            {
518                EnumSet<Namespace> result = EnumSet.noneOf(Namespace.class);
519    
520                for (EnumSet s : set)
521                    result.addAll(StpException.<EnumSet<Namespace>>unchecked_cast(s));
522    
523                return result;
524            }
525            
526            /**
527             * Determines whether this namespace is valid (not NONE or INVALID).
528             * 
529             * @return <b>true</b> if this Namespace represents a valid namespace;
530             * <b>false</b> otherwise.
531             */
532            public boolean isValid()
533            {
534                return valid.contains(this);
535            }
536    
537            /**
538             * @return <b>true</b> iff this namespace prefixes a path scheme
539             */
540            public boolean isPathScheme()
541            {
542                return pathSchemes.contains(this);
543            }
544    
545            /**
546             * @return <b>true</b> iff this namespace prefixes a file path scheme.
547             */
548            public boolean isFilePathScheme()
549            {
550                return filePathSchemes.contains(this);
551            }
552    
553    
554            /**
555             * @return <b>true</b> iff this namespace prefixes a path scheme
556             *         selector for the name of a repository (or repository-like
557             *         entity not in a repository). Said path is the value of the
558             *         Repo field rather than the Name field of an StpLocation.
559             */
560            public boolean isRepositoryPathScheme()
561            {
562                return repositoryPathSchemes.contains(this);
563            }
564    
565    
566            /**
567             * @return <b>true</b> iff this namespace prefixes a path scheme
568             *         selector expressed as a URL or URI. The complete URI,
569             *         including this prefix is contained wholly within the Name
570             *         field of the StpLocation
571             */
572            public boolean isUrlPathScheme()
573            {
574                return urlPathSchemes.contains(this);
575            }
576    
577            /**
578             * @return <b>true</b> iff this namespace requires additional segments
579             *         to complete its specification.
580             */
581            public boolean isExtendedNamespace()
582            {
583                return extendedNamespaces.contains(this);
584            }
585    
586            /**
587             * @return Whether or not the name field of a location specification
588             *         prefixed by this namespace should be %-escaped encoded.
589             */
590            public boolean isEscapeEncoded()
591            {
592                return escapeEncoded.contains(this);
593            }
594    
595            /**
596             * Creates a new Namespace object given its namespace field image.
597             * 
598             * @param symbol The identifier used in the namespace field to denote
599             *            this namespace.
600             */
601            private Namespace(String symbol)
602            {
603                m_namespaceField = symbol;
604            }
605    
606            /** A map from namespace Symbol to Namespace */
607            private static Map<String, Namespace> g_symbolToNamespaceMap =
608                new Hashtable<String, Namespace>();
609    
610            static {
611                for (Namespace n : Namespace.values())
612                    if (null != g_symbolToNamespaceMap.put(n.m_namespaceField,
613                                                           n)) {
614                        throw new IllegalArgumentException
615                        ("Duplicate Selector.Namespace symbol" /* NOI18N */);
616                    }
617            }
618    
619            /** The symbol used in a selector to denote this Namespace */
620            private String m_namespaceField;
621    
622            /** Serialization version UID */
623            private static final long serialVersionUID = -3736971155548723312L;
624        }
625    
626        /**
627         * The characters within a location specification that syntactically delimit
628         * the fields of the selector.
629         */
630        static final String FIELD_DELIMITERS = "@" /* NOI18N */;
631    
632        /**
633         * The characters within a selector field that syntactically delimit the
634         * segments of a field.
635         */
636        static final String SEGMENT_DELIMITERS = "/\\" /* NOI18N */;
637    
638        /**
639         * The characters within a selector that syntactically delimit the fields
640         * and segments embedded within the selector.
641         */
642        static final String DELIMITERS = FIELD_DELIMITERS + SEGMENT_DELIMITERS;
643    
644        /**
645         * If one of the characters of DELIMITERS is to be part of a name segment it
646         * must be protected from its syntactic interpretation by preceding it with
647         * this escape character. The escape character must also be escaped if it is
648         * to be part of a name segment.
649         */
650        static final String ESCAPE_CHAR = "%" /* NOI18N */;
651    
652        /**
653         * Overall status of this StpLocation
654         * 
655         * @return <b>true</b> if all required fields were found in the given
656         *         location specification.
657         */
658        boolean isOk();
659    
660        /**
661         * Generates an StpException object that reports the state of this
662         * StpLocation.
663         * 
664         * @return An StpException whose message reports the state of this
665         *         StpLocation. Will be <b>null</b> if this StpLocation is valid.
666         */
667        StpException status();
668    
669        /**
670         * Throws an INVALID_OBJECT_SELECTOR StpException if this StpLocation does
671         * not reflect a syntactically complete and correct location specification.
672         * 
673         * @throws StpException if any required fields are missing from the
674         *             StpLocation specification.
675         */
676        void throwIfNotOk() throws StpException;
677    
678        /**
679         * Returns whether or not this location is specified using a pathname
680         * format. Such locations specify a location as a segmented pathname
681         * following an explicit scheme prefix:
682         * <p>[<i>domain</i> .] <i>namespace</i> : <i>segmented-path</i>.
683         * <p>
684         * The segmented-path is the value of either the name field or the repo
685         * field of this StpLocation and the other field is not used and empty. The
686         * segmented path is stored in the name field unless the predicate
687         * {@link #isRepositoryPathScheme} is also <b>true</b>.
688         * <p>
689         * Included in this scheme classification are the location specifications
690         * that are not complete enough to classify more precisely; i.e. it includes
691         * the locations with the following special Namespace values.
692         * <ul>
693         * <li>NONE: The location specification did not include a scheme delimiter
694         * (":") (at least, not before the first occurrence of a character not
695         * allowed in a scheme prefix). The original input is in the name field of
696         * this StpLocation.
697         * <li>INVALID: The location specification began with a syntactically valid
698         * scheme prefix, but the spelling of the namespace subfield did not match
699         * any known namespace. The location was parsed as a path-scheme location
700         * with all text following the first ':' stored in the name field. The
701         * apparently misspelled namespace field is available from the
702         * ExtendedNamespace field of this StpLocation.
703         * <li>DEFAULT: The location specification began with a syntactically valid
704         * scheme prefix, but the namespace field was empty. The location was parsed
705         * as a path-scheme location, with all text following the first ':' stored
706         * in the name field.
707         * </ul>
708         * 
709         * @return <b>true</b> if this is a path-scheme location; <b>false</b> otherwise
710         */
711        boolean isPathScheme();
712    
713        /**
714         * Returns whether or not this location is specified using the URL path-
715         * scheme format. Such locations are formatted as standards-conforming URLs
716         * (URL-encoded). The entire URL, including the scheme-prefix of the URL,
717         * such as "http:" or "file:" is included in the name field of the
718         * StpLocation object. An optional domain field is permitted before the
719         * scheme-prefix, but it is not included in the name field. A URL path
720         * scheme is a specialized form of path scheme. The URL could designate a
721         * server, a repository, or a resource inside or outside of a repository.
722         * The URL is stored in the repo field if {@link #isRepositoryPathScheme} is
723         * <b>true</b>; otherwise it is stored in the name field.
724         * 
725         * @return <b>true</b> if this is a URL path-location; <b>false</b>
726         *         otherwise
727         */
728        boolean isUrlPathScheme();
729    
730        /**
731         * Returns whether or not this location specifies a repository using a path-
732         * scheme format. Such locations have a repository field specified as a
733         * segmented pathname (un-encoded). A repository path-scheme is a
734         * specialized form of path-scheme in which the path is found in the repo
735         * field of the StpLocation object. For all other forms of path-location the
736         * path is found in the name field of the StpLocation object.
737         * 
738         * @return <b>true</b> if this is a repository path-location; <b>false</b>
739         *         otherwise
740         */
741        boolean isRepositoryPathScheme();
742    
743        /**
744         * Returns whether or not this location is specified using the file path-
745         * scheme format. In this format, the resource location is specified in the
746         * name field of this StpLocation as a segmented pathname (using native file
747         * system encoding conventions) to a file system object, perhaps extended by
748         * a ClearCase history-mode selector. The variant of the file path location
749         * format used in the specification of this StpLocation is indicated by the
750         * value of getNamespace().
751         * <ul>
752         * <li>FILE: The "file:" URL scheme prefix was used to specify this
753         * StpLocation. Since this is also a URL path-scheme, the file-scheme prefix
754         * is included in the name field of this object. Conversion of this location
755         * to a File via {@link #getFile()} or canonical path via
756         * {@link #getCanonicalPath()} will first use the java.net.URI class to
757         * parse the file URL.
758         * <li>PNAME: This location was specified with an explicit "pname:" prefix.
759         * The "pname:" prefix is <i>not</i> included in the name field of this
760         * object; it contains only the characters following "pname:"
761         * <li>PNAME_IMPLIED: This location was not specified with an explicit
762         * "pname:" prefix but is being treated as if it were a pname. The implied
763         * "pname:" prefix is <i>not</i> included in the name field of this object
764         * nor does it appear in the string image of this StpLocation.
765         * </ul>
766         * <p>
767         * Note that this and the other predicates are purely syntactic. The user
768         * may have intended to name a file, but if it so happens that its name
769         * looks exactly like a valid object selector, it will be parsed and
770         * classified as an object selector. {@link #isObjectSelectorScheme()} will
771         * be <b>true</b> not {@link #isFilePathScheme()}. Clients wishing to
772         * interpret a location as a file path location, may always use the
773         * {@link #getFile()} or {@link #getCanonicalPath()} methods to investigate
774         * that option further. If this StpLocation isn't in the FILE or PNAME
775         * namespace, these methods will use the original input in its entirety as
776         * the intended pathname.
777         * <p>
778         * Similarly, {@link #recomposeWithNamespace(StpLocation.Namespace) 
779         * recomposeWithNamespace(Namespace.PNAME)} will "do the right thing" and
780         * force the original input into an explicit file path selector. Note,
781         * however, that in this case, the image of that StpLocation will include
782         * the "pname:" prefix.
783         * 
784         * @return <code><b>true</b></code> if this selector is most likely a
785         *         pathname to a file system object, <code><b>false</b></code> if
786         *         there is a more likely interpretation.
787         */
788        boolean isFilePathScheme();
789    
790        /**
791         * Returns whether or not this file-path scheme location uses the optional
792         * ClearCase history-mode naming syntax.
793         * 
794         * @return <b>true</b> if the name segment of this location contains
795         *         history-mode naming syntax.
796         */
797        boolean isHistoryModeScheme();
798    
799        /**
800         * Returns whether or not this location uses either a stable, fast
801         * (efficient), or user-friendly object selector scheme. Locations using the
802         * object selector format have a pre-defined namespace and separate name and
803         * repository fields.
804         * 
805         * @return <b>true</b> if this location uses the object selector format;
806         *         <b>false</b> otherwise, in which case it uses either a path
807         *         scheme.
808         */
809        boolean isObjectSelectorScheme();
810    
811        /**
812         * Returns whether or not this location uses an object selector scheme with
813         * user-friendly namespace, name, and repository fields.
814         * 
815         * @return <b>true</b> if this is an object name selector; <b>false</b>
816         *         otherwise.
817         * 
818         */
819        boolean isUserFriendlySelectorScheme();
820    
821        /**
822         * Returns whether or not this location uses an object selector scheme with
823         * a compound REPO namespace. Its name and repository fields are densely
824         * encoded for greater stability and more efficient retrieval.
825         * 
826         * @return <b>true</b> if the location uses the REPO namespace; <b> false</b>
827         *         otherwise.
828         */
829        boolean isRepoSelectorScheme();
830    
831        /**
832         * Returns whether or not this location uses an object selector scheme with
833         * a compound FAST namespace. Its name and repository fields are densely
834         * encoded for greater stability and more efficient retrieval.
835         * 
836         * @return <b>true</b> if the location uses the FAST namespace; <b> false</b>
837         *         otherwise.
838         */
839        boolean isFastSelectorScheme();
840    
841        /**
842         * Returns whether or not this location uses an object selector scheme with
843         * a compound OID namespace. Its name and repository fields are densely
844         * encoded for greater stability and more efficient retrieval.
845         * 
846         * @return <b>true</b> if the location uses the OID namespace; <b> false</b>
847         *         otherwise.
848         */
849        boolean isOidSelectorScheme();
850    
851        /**
852         * Returns the StpLocation.Namespace of this selector.
853         * <p>
854         * The special Namespace.INVALID indicates that the namespace field was
855         * present but spelled different from any namespace known to the library.
856         * <p>
857         * The special Namespace.DEFAULT indicates that the namespace field was
858         * present but empty, indicating that the default namespace ought to be
859         * used.
860         * <p>
861         * The special Namespace.NONE indicates that the namespace field was not
862         * present (i.e. there was no ':' in the specification before the first
863         * occurrence of a character not allowed in a scheme prefix), making it
864         * quite likely that this is a file selector.
865         * <p>
866         * Namespace.HTTP, Namespace.HTTPS, and Namespace.FILE indicate that the
867         * selector used the URI/URL syntax, the entirety of which is present in the
868         * name property.
869         * <p>
870         * Namespace.PNAME indicates that the selector used the PNAME namespace
871         * prefix. The file pathname following the PNAME prefix is the value of the
872         * name field.
873         * <p>
874         * See the complete list of possible namespaces in the Namespace enum
875         * specification.
876         * 
877         * @return The namespace used in this location specification as a Namespace
878         *         object. This will never be <b>null</b>.
879         */
880        Namespace getNamespace();
881    
882        /**
883         * Returns the resource type field of a location specification if it used a
884         * compound namespace.
885         * 
886         * @return The resource type segment of this StpLocation. This field is
887         *         defined only for compound namespace locations (i.e. those that
888         *         use Namespace.REPO, Namespace.FAST, or Namespace.OID). It will be
889         *         an empty string otherwise.
890         */
891        String getResourceType();
892    
893        /**
894         * An object containing additional information associated with certain
895         * Namespace enumerators.
896         */
897        interface ExtendedNamespace
898        {
899    
900            /**
901             * @return Returns the namespace.
902             */
903            Namespace getNamespace();
904    
905            /**
906             * @return Returns the resource type portion of the compound REPO
907             *         namespace field. Returns the empty string if the namespace is
908             *         not REPO, FAST, or OID.
909             */
910            String getResourceType();
911    
912            /**
913             * The image of the extended namespace field. For Namespace.REPO, FAST,
914             * or OID, this includes the resource type subfield; for
915             * Namespace.INVALID, this is the (misspelled) namespace field as
916             * entered.
917             * 
918             * @return A String containing the image of the namespace field for this
919             *         extended namespace (without the delimiting ':'). Will be
920             *         empty if the namespace is DEFAULT and <b>null</b> if the
921             *         location specification has no namespace field separate from
922             *         the name field, i.e. if the namespace is NONE, PNAME_IMPLIED,
923             *         HTTP, HTTPS, or FILE.
924             */
925            String toNamespaceField();
926    
927            /**
928             * Generates a debug image for this ExtendedNamespace object
929             * 
930             * @return Returns the value of {@link #toNamespaceField()},
931             *         substituting "&lt;null>" for <b>null</b>.
932             */
933            public String toString();
934        }
935    
936        /**
937         * Returns an ExtendedNamespace object that, for some namespaces, contains
938         * additional information about the namespace field beyond its Namespace
939         * value.
940         * 
941         * @return For a REPO, FAST, or OID namespace, the ExtendedNamespace
942         *         specifies the resource type segment that is associated with it;
943         *         for an INVALID namespace, the ExtendedNamespace object specifies
944         *         the misspelled namespace field; for other namespaces, no
945         *         additional information is available. Will not be <b>null</b>.
946         */
947        ExtendedNamespace getExtendedNamespace();
948    
949        /**
950         * Returns the object name field specified for this location. This field is
951         * relevant and meaningful in all schemes <i>except</i> the repository-path
952         * scheme. In a repository-path scheme, it will be an empty Sting. The
953         * encoding of the returned String is unchanged from the original input.
954         * 
955         * @return An empty string for a repository-path-scheme location; otherwise
956         *         the object name field of an object selector or the pathname of a
957         *         path-scheme location. Will be never be <b> null</b>, but may be
958         *         empty.
959         */
960        String getName();
961    
962        /**
963         * The number of segments in the object name.
964         * 
965         * @return The length of the Sting array returned by
966         *         {@link #getNameSegments(int) getNameSegments(Integer.MAX_VALUE)}.
967         */
968        int getNameSegmentCount();
969    
970        /**
971         * Returns the first N segments of the name field of this location
972         * specification. If the requested number of segments is greater than the
973         * number in the name field, the entire name is returned; if zero or less,
974         * an empty array is returned.
975         * <p>
976         * Constructs a String array containing the segments of the given field. The
977         * elements of the array are the character sequences that preceded each
978         * segment delimiter plus the character sequence at the end of the field not
979         * followed by a delimiter as long as it is not empty. Thus, the array is
980         * empty if the field is empty; otherwise, the array has N+1 segments, where
981         * N is the number of segment delimiters in the field not counting the last
982         * delimiter if it appears at the end of the field.
983         * <p>
984         * The following examples illustrate the way a field is segmented.
985         * 
986         * <pre>
987         *  "" ==> {}
988         *  "fob/bar" ==> {"fob", "bar"}
989         *  "fob/" ==> {"fob"}
990         *  "fob" ==> {"fob"}
991         *  "/fob" ==> {"", "fob"}
992         *  "/" ==> {""}
993         *  "//" ==> {"", ""}
994         *  "fob//bar" ==> {"fob", "", "bar"}
995         *  "http://server" ==> {"http:", "", "server"}
996         *  "http://" ==> {"http:", ""}
997         *  "file:///" ==> {"file", "", ""}
998         * </pre>
999         * 
1000         * Note that a trailing segment delimiter is "lost" only if it follows a
1001         * non-empty segment. Consequently, when reconstructing the field from the
1002         * array, segment delimiters should be inserted between each array element
1003         * and a trailing delimiter should be added only if the last segment is
1004         * empty.
1005         * 
1006         * <p>
1007         * Note: The returned segments are encoded just as they were on input to the
1008         * constructor. Any escape characters present in the field on input remain
1009         * in each returned segment. Only the unescaped segment delimiters have been
1010         * removed from the input field.
1011         * 
1012         * @param nSegs the number of segments to return
1013         * 
1014         * @return a String array containing the first nSegs segments of the name
1015         *         field of this StpLocation.
1016         */
1017        String[] getNameSegments(int nSegs);
1018    
1019        /**
1020         * Returns contiguous segments of the name field of this selector. Segments
1021         * returned are in the intersection of the specified range and the actual
1022         * range of name segments. The first segment is at index zero.
1023         * 
1024         * <p>
1025         * Note: The returned segments are encoded just as they were on input to the
1026         * constructor. Any escape characters present in the field on input remain
1027         * in each returned segment. Only the unescaped segment delimiters have been
1028         * removed from the input field.
1029         * 
1030         * @param firstSeg the first segment to include
1031         * @param lastSeg the last segment to include
1032         * 
1033         * @return the requested segments of the object name. Will never be null,
1034         *         but may be empty if the specified range includes none of the
1035         *         segments of the name field.
1036         */
1037        String[] getNameSegments(int firstSeg,
1038                                 int lastSeg);
1039    
1040        /**
1041         * Returns the repository field of this location specification. This field
1042         * is irrelevant and empty in any path scheme location that does not have a
1043         * repository field. Conversely, if this location specification specified a
1044         * repository, it will be in this field.
1045         * 
1046         * @return An empty string if there was no repository field found in the
1047         *         location specification; otherwise the image of the repository
1048         *         field (without a repository field delimiter).
1049         */
1050        String getRepo();
1051    
1052        /**
1053         * The number of segments in the repository name.
1054         * 
1055         * @return The length of the String array returned by
1056         *         {@link #getRepoSegments(int) getRepoSegments(Integer.MAX_VALUE)}.
1057         */
1058        int getRepoSegmentCount();
1059    
1060        /**
1061         * Returns the first N segments of the repository field of this location. If
1062         * the requested number of segments is greater than the number in the
1063         * repository name, the entire repository name is returned; if zero or less,
1064         * an empty array is returned.
1065         * 
1066         * <p>
1067         * Note: The returned segments are encoded just as they were on input to the
1068         * constructor. Any escape characters present in the field on input remain
1069         * in each returned segment. Only the unescaped segment delimiters have been
1070         * removed from the input field.
1071         * 
1072         * @param nSegs the number of segments to return
1073         * 
1074         * @return a String containing the first nSegs segments of the repository
1075         *         name.
1076         * 
1077         * @see #getNameSegments(int) for a description of how segments are parsed
1078         *      and counted.
1079         */
1080        String[] getRepoSegments(int nSegs);
1081    
1082        /**
1083         * Returns contiguous segments of the repository name of this location.
1084         * Segments returned are in the intersection of the specified range and the
1085         * actual range of name segments. The first segment is at index zero.
1086         * 
1087         * <p>
1088         * Note: The returned segments are encoded just as they were on input to the
1089         * constructor. Any escape characters present in the field on input remain
1090         * in each returned segment. Only the unescaped segment delimiters have been
1091         * removed from the input field.
1092         * 
1093         * @param firstSeg the first segment to include
1094         * @param lastSeg the last segment to include
1095         * 
1096         * @return the requested segments of the repository name. Will never be
1097         *         null, but may be empty if the specified range includes none of
1098         *         the segments of the name.
1099         */
1100        String[] getRepoSegments(int firstSeg,
1101                                 int lastSeg);
1102    
1103        /**
1104         * Returns the domain specified or implied by the selector. In
1105         * URL-path-scheme locations this field is optional and will be NONE if no
1106         * domain information is available. In the other formats, the value NONE
1107         * denotes the default domain.
1108         * 
1109         * @return Returns the StpProvider.Domain. Will never be <b>null</b>, but
1110         *         may be {@link StpProvider.Domain#NONE NONE} or {@link
1111         *         StpProvider.Domain#INVALID INVALID}.
1112         */
1113        StpProvider.Domain getDomain();
1114    
1115        /**
1116         * Reconstitutes the location specification from its component fields.
1117         * 
1118         * @return For a valid StpLocation, a syntactically correct location
1119         *         specification string composed from the current values for the
1120         *         namespace, name, domain, and repo fields; otherwise the location
1121         *         specification as passed to the constructor.
1122         * 
1123         * @see java.lang.Object#toString()
1124         */
1125        String toString();
1126    
1127        /**
1128         * As above, but returns a location string <i>without</i> the domain
1129         * prefix.
1130         */
1131        String toStringWithoutDomain();
1132    
1133        /**
1134         * @see java.lang.Object#equals(java.lang.Object)
1135         */
1136        boolean equals(Object arg0);
1137    
1138        /**
1139         * Uses the hash code of the composed String image
1140         * 
1141         * @see java.lang.Object#hashCode()
1142         */
1143        int hashCode();
1144    
1145        /**
1146         * Constructs an StpLocation object based on the fields of this StpLocation
1147         * with optional replacements for some of the fields. A <b>null</b>
1148         * argument generally means to use the corresponding field of this
1149         * StpLocation in the new StpLocation.
1150         * <p>
1151         * NOTE: This method does not change the host StpLocation object. But
1152         * constructs and returns a new instance of StpLocation.
1153         * 
1154         * @param namespace The namespace for the new location expressed either as
1155         *            an ExtendedNamespace object, a Namespace enumeration or as a
1156         *            String containing the resource type of a REPO namespace. If
1157         *            namespace is Namespace.NONE no namespace prefix is generated
1158         *            for the selector. If namespace is <b>null</b>, the current
1159         *            value of getExtendedNamespace() is used.
1160         * @param name The name field of the new selector. If <b>null</b>, the
1161         *            current value of getName() is used.
1162         * @param domain The StpProvider.Domain for the new selector. If null, the
1163         *            current value of getDomain() is used.
1164         * @param repo The repository field for the new selector. If <b>null</b>,
1165         *            the current value of getRepo() is used. Must be <b>null</b>
1166         *            for path-path scheme locations that are not
1167         *            repository-path-schemes. If empty, no repository field will be
1168         *            generated for the selector.
1169         * 
1170         * @return A new StpLocation composed from the current namespace, name, type
1171         *         and repo fields, optionally overwritten by the given arguments.
1172         * 
1173         * @throws StpException Thrown if the given selector String is not in the
1174         *             correct form. StpReasonCode=INVALID_OBJECT_SELECTOR
1175         */
1176        StpLocation recomposeWithMods(Object namespace,
1177                                      String name,
1178                                      StpProvider.Domain domain,
1179                                      String repo) throws StpException;
1180    
1181        /**
1182         * Constructs new location based on this location but with a replacement for
1183         * its namespace field.
1184         * 
1185         * @param namespace The namespace for the new StpLocation. If namespace is
1186         *            Namespace.NONE, no namespace prefix is generated for the
1187         *            selector. If namespace is <b>null</b>, the current value of
1188         *            Namespace is used, effectively cloning this StpLocation
1189         *            object.
1190         * 
1191         * @return An StpLocation composed from the current name, domain and repo
1192         *         fields and the specified namespace argument.
1193         * 
1194         * @throws StpException if the given selector String is not in the
1195         *             correct form. StpReasonCode=INVALID_OBJECT_SELECTOR
1196         */
1197        StpLocation recomposeWithNamespace(StpLocation.Namespace namespace)
1198            throws StpException;
1199    
1200        /**
1201         * Constructs a new location based on this location with a replacement for
1202         * its name field.
1203         * 
1204         * @param name The new selector name field. If null, the current value of
1205         *            name() is used.
1206         * 
1207         * @return The selector composed from the current namespace, domain and repo
1208         *         fields and the specified name argument.
1209         * 
1210         * @throws StpException Thrown if the given selector String is not in the
1211         *             correct form. StpReasonCode=INVALID_OBJECT_SELECTOR
1212         */
1213        StpLocation recomposeWithName(String name) throws StpException;
1214    
1215        /**
1216         * Constructs a new location based on this location with a replacement for
1217         * its repository field.
1218         * 
1219         * @param repo The new repository field for the location. If <b>null</b>,
1220         *            the current value of getRepo() is used. If empty, no
1221         *            repository field will be generated for the location.
1222         * 
1223         * @return An StpLocation composed from the current namespace, name, and
1224         *         domain fields and the specified repo argument.
1225         * 
1226         * @throws StpException Thrown if the given selector String is not in the
1227         *             correct form. StpReasonCode=INVALID_OBJECT_SELECTOR
1228         */
1229        StpLocation recomposeWithRepo(String repo) throws StpException;
1230    
1231        /**
1232         * Constructs a new location based on this location with a replacement for
1233         * its domain field.
1234         * 
1235         * @param domain The new domain for the selector. If <b>null</b>, the
1236         *            current value of getDomain() is used.
1237         * 
1238         * @return An StpLocation composed from the current namespace, name, and
1239         *         repo fields and the specified domain argument.
1240         * 
1241         * @throws StpException Thrown if the given selector String is not in the
1242         *             correct form. StpReasonCode=INVALID_OBJECT_SELECTOR
1243         */
1244        StpLocation recomposeWithDomain(StpProvider.Domain domain)
1245            throws StpException;
1246    
1247        /**
1248         * Constructs an object selector with a replacement for its resource type
1249         * field, forcing the namespace to REPO.
1250         * 
1251         * @param rType The resource type for the new location. If <b>null</b>, the
1252         *            current value of getResourceType() is used.
1253         * 
1254         * @return A stable-selector scheme StpLocation composed from the current
1255         *         name, repo and domain fields and the specified resource type.
1256         * 
1257         * @throws StpException Thrown if the given selector String is not in the
1258         *             correct form. StpReasonCode=INVALID_OBJECT_SELECTOR
1259         */
1260        StpLocation recomposeWithResourceType(String rType) throws StpException;
1261    
1262        /**
1263         * Constructs an StpLocation for a pname based on the image of this
1264         * StpLocation. The StpLocation can be constructed with or without a pname
1265         * prefix and can be assigned a StpProvider.Domain.
1266         * <p>
1267         * In most cases, the entire image of this StpLocation (as returned by
1268         * toString()) becomes the value of the name field of the returned
1269         * StpLocation even if that image includes a namespace and/or a domain
1270         * prefix. The domain prefix can be elided from the name field of the new
1271         * location by using <b>null</b> for the domain argument to this method.
1272         * <p>
1273         * To convert any ill-formed selector to an implied pname, the following
1274         * logic might be used <code><pre>
1275         * if (!myLoc.isOk()) {
1276         *      // Convert to an implied pname so that it prints as it was
1277         *      // entered, but is treated internally as an OK file path selector
1278         *      myLoc = myLoc.recomposeAsPname(false, MY_DOMAIN);
1279         * }
1280         * </pre></code>
1281         * <p>
1282         * To convert any input not already formatted as a file-path-scheme location
1283         * to an explicit pname, the following logic might be used <code><pre>
1284         * if (!(myLoc.isFilePathScheme() && myLoc.isOk())) {
1285         *      myLoc = myLoc.recomposeAsPname(true, MY_DOMAIN);
1286         * }
1287         * </pre></code>
1288         * <p>
1289         * To convert all input to an implied pname, the following logic might be
1290         * used <code><pre>
1291         *  if (myLoc.getNamespace() == Namespace.PNAME) {
1292         *      // Keep the original "pname:" prefix out of the implied pname
1293         *      // Preserve any domain data from the input. 
1294         *      myLoc = myLoc.recomposeWithNamespace(Namespace.PNAME_IMPLIED);
1295         *  } else if (myLoc.getNamespace() == Namespace.FILE) {
1296         *      // Remove any domain info from the "file:" prefix, but push the
1297         *      // rest of the "file:" prefix into the pname.
1298         *      myLoc = myLoc.recomposeAsPname(false, null);
1299         *  } else {
1300         *      // All other input not using an explicit pname: or file: prefix is
1301         *      // treated as a raw pname.
1302         *      myLoc = myLoc.recomposeAsPname(false, MY_DOMAIN);
1303         *  }
1304         *  
1305         *  // Set the domain type if not already specified.
1306         *  if (myLoc.getDomain() == Domain.NONE)
1307         *      myLoc = recomposeWithType(MY_DOMAIN);
1308         * </pre></code>
1309         * 
1310         * @param withPrefix if <b>true</b>, the namespace of the returned
1311         *            StpLocation will be Namespace.PNAME; if <b>false</b>, the
1312         *            namespace will be Namespace.PNAME_IMPLIED.
1313         * @param domain The StpProvider.Domain of the returned StpLocation. If
1314         *            <b>null</b> the StpProvider.Domain of the current StpLocation
1315         *            will be used <i>and the image of that domain will be elided
1316         *            from the pname.</i>
1317         * @return An StpLocation reconfigured as a Pname instance, explicit or
1318         *         implied as requested
1319         */
1320        StpLocation recomposeAsPname(boolean withPrefix,
1321                                     StpProvider.Domain domain) throws StpException;
1322    
1323        /**
1324         * Constructs a location suitable for addressing resources of the type
1325         * indicated by the supplied proxy class by filling in unspecified fields of
1326         * this location using provider-defined or resource-type-dependent defaults.
1327         * <p>
1328         * Note, when an StpLocation object is passed to a Provider proxy factory
1329         * method this forClass is implicitly invoked using the Class of the proxy
1330         * returned by the proxy factory method. Similarly, when an StpLocation is
1331         * passed to a method of a proxy, that method implicitly invokes forClass
1332         * using a proxy class deduced from the host proxy and the operation.
1333         * <p>
1334         * Clients need to use this method only if they want to complete/verify a
1335         * location used in some other context or more tightly than can be
1336         * determined from the proxy context.
1337         * 
1338         * @param proxyClass The Class object for the proxy interface for which this
1339         *            location is to be completed.
1340         * @return An StpLocation suitable for use with a proxy of the given class.
1341         *         The result will be this location if it is already suitable and a
1342         *         new StpLocation if not; will never be <b>null</b>.
1343         * @throws WvcmException if it is not possible to complete the location from
1344         *             available defaults or if the completed location is
1345         *             inappropriate in some other (obvious) way, such as having a
1346         *             domain or namespace inconsistent with the given class.
1347         */
1348        StpLocation forClass(Class<? extends Resource> proxyClass) throws WvcmException;
1349    
1350        /**
1351         * Returns an StpLocation whose segmented name field is one segment shorter
1352         * than the name field of this StpLocation <i>provided</i> the name field
1353         * of the resulting StpLocation would be valid. All other fields of the
1354         * StpLocation are left unchanged.
1355         * <p>
1356         * NOTE: For repository-path scheme locations this method operates on the
1357         * segmented repo field rather than the name field. But in all other
1358         * respects the behavior is the same.
1359         * <p>
1360         * For object-selector scheme locations, an empty name field is valid, but
1361         * for path-scheme locations, the name/repo field is valid only if it
1362         * contains at least one segment of the original path (even if that segment
1363         * is empty). These examples illustrate the edge cases <code><pre>
1364         *      StpLocation        |    Parent        
1365         *      -------------------+---------------
1366         *      /food              | /        
1367         *      vob:/food          | vob:/      
1368         *      http://server/path | http://server 
1369         *      file://author/path | file://author 
1370         *      http://server      | &lt;null&gt; 
1371         *      file://author      | &lt;null&gt; 
1372         *      pname:path         | &lt;null&gt;      
1373         *      file:/             | &lt;null&gt;      
1374         * </pre></code>
1375         * 
1376         * @return A new StpLocation instance; will be <b>null</b> if the name
1377         *         field of this StpLocation has no segments that can be removed.
1378         */
1379        Location parent();
1380    
1381        /**
1382         * Returns an StpLocation whose name field is the name field of this
1383         * StpLocation extended by the given child segment. All other fields are the
1384         * same as the fields of this StpLocation. For repository-path-scheme
1385         * locations, the repo field is extended rather than the name field.
1386         * <p>
1387         * Unlike most of the other methods of this class, the child() method
1388         * encodes the new child segment according to the requirements of the
1389         * scheme. Thus, this method may be used to add only one segment at a time
1390         * to the StpLocation. In any scheme, any embedded segment delimiters in the
1391         * child segment will be encoded to make them part of the segment.
1392         * <p>
1393         * Even if this method successfully returns an StpLocation, there is no
1394         * guarantee that the returned location is a valid resource location. The
1395         * returned location may be invalid even if the original location was valid.
1396         * Some resources simply do not have parents even though their location
1397         * suggests that they do.
1398         * <p>
1399         * For example, <b>field:Defect/Headline@7.0.0.0/SAMPL</b> is the location
1400         * for the description of the <b>Headline</b> field of the <b>Defect</b>
1401         * record type in the sample ClearQuest database. However, its parent
1402         * location, <b>field:Defect@7.0.0.0/SAMPL</b>, is <i>not</i> a valid
1403         * location. While this may seem to address the <b>Defect</b> record type
1404         * resource, it does not. The location for the <b>Defect</b> record type
1405         * resource is, in fact, <b><u>record</u>:Defect@7.0.0.0/SAMPL</b>, which
1406         * is in a different namespace from the parent of the field description
1407         * resource.
1408         * <p>
1409         * In general, clients are discouraged from manipulating locations to
1410         * traverse the object model. They should use the properties defined for
1411         * this purpose instead. If, for example, the client wants to traverse from
1412         * a field description to the record type of that field, then it should use
1413         * the RECORD_TYPE property of the field rather than taking the parent and
1414         * changing the namespace. Note that if the field location is a
1415         * stable-selector scheme location, simply changing the namespace of the
1416         * parent will not work.
1417         * 
1418         * @param child The new segment to be appended to the name field of this
1419         *            StpLocation. To be consistent with the Location.child method,
1420         *            it is assumed that the String is not yet encoded. It will be
1421         *            encoded as a single segment before adding it to the name
1422         *            field.
1423         * 
1424         * @return A new StpLocation with an extended name field.
1425         */
1426        Location child(String child);
1427    
1428        /**
1429         * Returns the last segment of the name field of this StpLocation. (Returns
1430         * the last segment of the repo field for repository-path-scheme locations.)
1431         * Any encoding used within the last segment is removed before returning a
1432         * value. Thus it's the case that
1433         * <b>loc.equals(loc.parent().child(loc.lastSegment()))</b> as long as
1434         * <b>loc.parent()</b> is not null.
1435         * <p>
1436         * At the root of the namespace (parent() returns &lt;null>), returns either
1437         * the name of the root or the empty string if the root is unnamed. These
1438         * examples illustrate the edge cases <code><pre>
1439         *      StpLocation        | lastSegment | parent        
1440         *      -------------------+-------------+------------- 
1441         *      /food              |   food      | /   
1442         *      /                  |  &lt;empty&gt;    | &lt;null&gt;       
1443         *      pname:/food        |   food      | pname:/
1444         *      http://server/path |   path      | http://server
1445         *      file://author/path |   path      | file://author
1446         *      http://server      |  &lt;empty&gt;    | &lt;null&gt;
1447         *      file://author      |  &lt;empty&gt;    | &lt;null&gt;
1448         *      pname:path         |   path      | &lt;null&gt;
1449         *      pname:/            |  &lt;empty&gt;    | &lt;null&gt;
1450         *      pname:\            |  &lt;empty&gt;    | &lt;null&gt;
1451         *      record:food@cq:s/u |   food      | record:@cq:s/u
1452         *      record:@cq:s/u     |  &lt;empty&gt;    | &lt;null&gt;
1453         * </pre></code>
1454         * 
1455         * @return A String containing the last segment of the name field of this
1456         *         StpLocation stripped of all encodings. Will never be null, but
1457         *         may be empty if the last segment is unnamed.
1458         */
1459        String lastSegment();
1460    
1461        /**
1462         * Interprets this StpLocation as a file-path-scheme location and returns
1463         * the <i>canonical</i> pathname for the file. If this StpLocation is not a
1464         * file-path-scheme location, the original location specification used to
1465         * construct this StpLocation is used as the pathname to be canonicalized.
1466         * <p>
1467         * For a location in the FILE namespace, this method constructs a URI from
1468         * the given file-scheme URL and then constructs a java.io.File from that
1469         * URI. Whether or not this succeeds depends on the JVM. (IBM's JVM 1.4.2,
1470         * for example, requires that the authority portion be empty.)
1471         * 
1472         * @see java.io.File#getCanonicalPath()
1473         * 
1474         * @return The canonicalized pathname for this resource. Will never be
1475         *         <b>null</b>.
1476         * 
1477         * @throws StpException if IO errors are encountered while determining the
1478         *             canonical path or converting the file-scheme URL to a File.
1479         */
1480        String getCanonicalPath() throws StpException;
1481    
1482        /**
1483         * Returns a File object that references the path defined by this
1484         * StpLocation. If this StpLocation is not a file-path-scheme location, the
1485         * original location specification used to construct this StpLocation is
1486         * used as the pathname from which the java.io.File object is constructed.
1487         * <p>
1488         * For a location in the FILE namespace, this method constructs a URI from
1489         * the given URL and then constructs a java.io.File from that URI. Whether
1490         * or not this succeeds depends on the JVM. (IBM's JVM 1.4.2, for example,
1491         * requires that the authority portion be undefined.)
1492         * 
1493         * @return A File object for the path defined by this StpLocation; Will
1494         *         never be <b>null</b>.
1495         * 
1496         * @throws MalformedURLException if the selector is a file scheme URL for
1497         *             which a File cannot be constructed.
1498         * @throws StpException
1499         * @throws IllegalStateException If {@link #isFilePathScheme()} is <b> false</b>.
1500         */
1501        File getFile() throws MalformedURLException, StpException;
1502    
1503    }