org.apache.xml.resolver

Class Catalog

Known Direct Subclasses:
Resolver

public class Catalog
extends Object

Represents OASIS Open Catalog files.

This class implements the semantics of OASIS Open Catalog files (defined by OASIS Technical Resolution 9401:1997 (Amendment 2 to TR 9401)).

The primary purpose of the Catalog is to associate resources in the document with local system identifiers. Some entities (document types, XML entities, and notations) have names and all of them can have either public or system identifiers or both. (In XML, only a notation can have a public identifier without a system identifier, but the methods implemented in this class obey the Catalog semantics from the SGML days when system identifiers were optional.)

The system identifiers returned by the resolution methods in this class are valid, i.e. usable by, and in fact constructed by, the java.net.URL class. Unfortunately, this class seems to behave in somewhat non-standard ways and the system identifiers returned may not be directly usable in a browser or filesystem context.

This class recognizes all of the Catalog entries defined in TR9401:1997:

Note that BASE entries are treated as described by RFC2396. In particular, this has the counter-intuitive property that after a BASE entry identifing "http://example.com/a/b/c" as the base URI, the relative URI "foo" is resolved to the absolute URI "http://example.com/a/b/foo". You must provide the trailing slash if you do not want the final component of the path to be discarded as a filename would in a URI for a resource: "http://example.com/a/b/c/".

Note that subordinate catalogs (all catalogs except the first, including CATALOG and DELEGATE* catalogs) are only loaded if and when they are required.

This class relies on classes which implement the CatalogReader interface to actually load catalog files. This allows the catalog semantics to be implemented for TR9401 text-based catalogs, XML catalogs, or any number of other storage formats.

Additional catalogs may also be loaded with the parseCatalog method.

Change Log:

xml.catalog.filesxml.catalog.files

 unquoted-path-with-no-sep-chars:"double-quoted path with or without sep chars":'single-quoted path with or without sep chars'
 

Version:
1.0

Derived from public domain code originally published by Arbortext, Inc.

Author:
Norman Walsh Norman.Walsh@Sun.COM
See Also:
CatalogReader, CatalogEntry

Field Summary

static int
BASE
The BASE Catalog Entry type.
static int
CATALOG
The CATALOG Catalog Entry type.
static int
DELEGATE_PUBLIC
The DELEGATE_PUBLIC Catalog Entry type.
static int
DELEGATE_SYSTEM
The DELEGATE_SYSTEM Catalog Entry type.
static int
DELEGATE_URI
The DELEGATE_URI Catalog Entry type.
static int
DOCTYPE
The DOCTYPE Catalog Entry type.
static int
DOCUMENT
The DOCUMENT Catalog Entry type.
static int
DTDDECL
The DTDDECL Catalog Entry type.
static int
ENTITY
The ENTITY Catalog Entry type.
static int
LINKTYPE
The LINKTYPE Catalog Entry type.
static int
NOTATION
The NOTATION Catalog Entry type.
static int
OVERRIDE
The OVERRIDE Catalog Entry type.
static int
PUBLIC
The PUBLIC Catalog Entry type.
static int
REWRITE_SYSTEM
The REWRITE_SYSTEM Catalog Entry type.
static int
REWRITE_URI
The REWRITE_URI Catalog Entry type.
static int
SGMLDECL
The SGMLDECL Catalog Entry type.
static int
SYSTEM
The SYSTEM Catalog Entry type.
static int
SYSTEM_SUFFIX
The SYSTEM_SUFFIX Catalog Entry type.
static int
URI
The URI Catalog Entry type.
static int
URI_SUFFIX
The URI_SUFFIX Catalog Entry type.
protected URL
base
The base URI for relative system identifiers in the catalog.
protected URL
catalogCwd
The base URI of the Catalog file currently being parsed.
protected Vector
catalogEntries
The catalog entries currently known to the system.
protected Vector
catalogFiles
A vector of catalog files to be loaded.
protected CatalogManager
catalogManager
The catalog manager in use for this instance.
protected Vector
catalogs
A vector of Catalogs.
protected boolean
default_override
The default initial override setting.
protected Vector
localCatalogFiles
A vector of catalog files constructed during processing of CATALOG entries in the current catalog.
protected Vector
localDelegate
A vector of DELEGATE* Catalog entries constructed during processing of the Catalog.
protected Vector
readerArr
A vector of CatalogReaders.
protected Hashtable
readerMap
A hash of CatalogReaders.

Constructor Summary

Catalog()
Constructs an empty Catalog.
Catalog(CatalogManager manager)
Constructs an empty Catalog with a specific CatalogManager.

Method Summary

protected void
addDelegate(CatalogEntry entry)
Add to the current list of delegated catalogs.
void
addEntry(CatalogEntry entry)
Cleanup and process a Catalog entry.
void
addReader(String mimeType, CatalogReader reader)
Add a new CatalogReader to the Catalog.
protected void
copyReaders(Catalog newCatalog)
Copies the reader list from the current Catalog to a new Catalog.
protected String
encodedByte(int b)
Perform %-encoding on a single byte.
protected String
fixSlashes(String sysid)
Replace backslashes with forward slashes.
CatalogManager
getCatalogManager()
Return the CatalogManager used by this catalog.
String
getCurrentBase()
Returns the current base URI.
String
getDefaultOverride()
Returns the default override setting associated with this catalog.
void
loadSystemCatalogs()
Load the system catalog files.
protected String
makeAbsolute(String sysid)
Construct an absolute URI from a relative one, using the current base URI.
protected Catalog
newCatalog()
Create a new Catalog object.
protected String
normalizeURI(String uriref)
Perform character normalization on a URI reference.
void
parseAllCatalogs()
Parse all subordinate catalogs.
void
parseCatalog(String fileName)
Parse a catalog file, augmenting internal data structures.
void
parseCatalog(String mimeType, InputStream is)
Parse a catalog file, augmenting internal data structures.
void
parseCatalog(URL aUrl)
Parse a catalog document, augmenting internal data structures.
protected void
parseCatalogFile(String fileName)
Parse a single catalog file, augmenting internal data structures.
protected void
parsePendingCatalogs()
Parse all of the pending catalogs.
String
resolveDoctype(String entityName, String publicId, String systemId)
Return the applicable DOCTYPE system identifier.
String
resolveDocument()
Return the applicable DOCUMENT entry.
String
resolveEntity(String entityName, String publicId, String systemId)
Return the applicable ENTITY system identifier.
protected String
resolveLocalPublic(int entityType, String entityName, String publicId, String systemId)
Return the applicable PUBLIC or SYSTEM identifier.
protected String
resolveLocalSystem(String systemId)
Return the applicable SYSTEM system identifier in this catalog.
protected String
resolveLocalURI(String uri)
Return the applicable URI in this catalog.
String
resolveNotation(String notationName, String publicId, String systemId)
Return the applicable NOTATION system identifier.
String
resolvePublic(String publicId, String systemId)
Return the applicable PUBLIC or SYSTEM identifier.
protected String
resolveSubordinateCatalogs(int entityType, String entityName, String publicId, String systemId)
Search the subordinate catalogs, in order, looking for a match.
String
resolveSystem(String systemId)
Return the applicable SYSTEM system identifier.
String
resolveURI(String uri)
Return the applicable URI.
void
setCatalogManager(CatalogManager manager)
Establish the CatalogManager used by this catalog.
void
setupReaders()
Setup readers.
void
unknownEntry(Vector strings)
Handle unknown CatalogEntry types.

Field Details

BASE

public static final int BASE
The BASE Catalog Entry type.

CATALOG

public static final int CATALOG
The CATALOG Catalog Entry type.

DELEGATE_PUBLIC

public static final int DELEGATE_PUBLIC
The DELEGATE_PUBLIC Catalog Entry type.

DELEGATE_SYSTEM

public static final int DELEGATE_SYSTEM
The DELEGATE_SYSTEM Catalog Entry type.

DELEGATE_URI

public static final int DELEGATE_URI
The DELEGATE_URI Catalog Entry type.

DOCTYPE

public static final int DOCTYPE
The DOCTYPE Catalog Entry type.

DOCUMENT

public static final int DOCUMENT
The DOCUMENT Catalog Entry type.

DTDDECL

public static final int DTDDECL
The DTDDECL Catalog Entry type.

ENTITY

public static final int ENTITY
The ENTITY Catalog Entry type.

LINKTYPE

public static final int LINKTYPE
The LINKTYPE Catalog Entry type.

NOTATION

public static final int NOTATION
The NOTATION Catalog Entry type.

OVERRIDE

public static final int OVERRIDE
The OVERRIDE Catalog Entry type.

PUBLIC

public static final int PUBLIC
The PUBLIC Catalog Entry type.

REWRITE_SYSTEM

public static final int REWRITE_SYSTEM
The REWRITE_SYSTEM Catalog Entry type.

REWRITE_URI

public static final int REWRITE_URI
The REWRITE_URI Catalog Entry type.

SGMLDECL

public static final int SGMLDECL
The SGMLDECL Catalog Entry type.

SYSTEM

public static final int SYSTEM
The SYSTEM Catalog Entry type.

SYSTEM_SUFFIX

public static final int SYSTEM_SUFFIX
The SYSTEM_SUFFIX Catalog Entry type.

URI

public static final int URI
The URI Catalog Entry type.

URI_SUFFIX

public static final int URI_SUFFIX
The URI_SUFFIX Catalog Entry type.

base

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

catalogCwd

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

catalogEntries

protected Vector catalogEntries
The catalog entries currently known to the system.

catalogFiles

protected Vector catalogFiles
A vector of catalog files to be loaded.

This list is initially established by loadSystemCatalogs when it parses the system catalog list, but CATALOG entries may contribute to it during the course of parsing.


catalogManager

protected CatalogManager catalogManager
The catalog manager in use for this instance.

catalogs

protected Vector catalogs
A vector of Catalogs.

The semantics of Catalog resolution are such that each catalog is effectively a list of Catalogs (in other words, a recursive list of Catalog instances).

Catalogs that are processed as the result of CATALOG or DELEGATE* entries are subordinate to the catalog that contained them, but they may in turn have subordinate catalogs.

Catalogs are only loaded when they are needed, so this vector initially contains a list of Catalog filenames (URLs). If, during processing, one of these catalogs has to be loaded, the resulting Catalog object is placed in the vector, effectively caching it for the next query.


default_override

protected boolean default_override
The default initial override setting.

localCatalogFiles

protected Vector localCatalogFiles
A vector of catalog files constructed during processing of CATALOG entries in the current catalog.

This two-level system is actually necessary to correctly implement the semantics of the CATALOG entry. If one catalog file includes another with a CATALOG entry, the included catalog logically occurs at the end of the including catalog, and after any preceding CATALOG entries. In other words, the CATALOG entry cannot insert anything into the middle of a catalog file.

When processing reaches the end of each catalog files, any elements on this vector are added to the front of the catalogFiles vector.


localDelegate

protected Vector localDelegate
A vector of DELEGATE* Catalog entries constructed during processing of the Catalog.

This two-level system has two purposes; first, it allows us to sort the DELEGATE* entries by the length of the partial public identifier so that a linear search encounters them in the correct order and second, it puts them all at the end of the Catalog.

When processing reaches the end of each catalog file, any elements on this vector are added to the end of the catalogEntries vector. This assures that matching PUBLIC keywords are encountered before DELEGATE* entries.


readerArr

protected Vector readerArr
A vector of CatalogReaders.

This vector contains all of the readers in the order that they were added. In the event that a catalog is read from a file, where the MIME type is unknown, each reader is attempted in turn until one succeeds.


readerMap

protected Hashtable readerMap
A hash of CatalogReaders.

This hash maps MIME types to elements in the readerArr vector. This allows the Catalog to quickly locate the reader for a particular MIME type.

Constructor Details

Catalog

public Catalog()
Constructs an empty Catalog.

The constructor interrogates the relevant system properties using the default (static) CatalogManager and initializes the catalog data structures.


Catalog

public Catalog(CatalogManager manager)
Constructs an empty Catalog with a specific CatalogManager.

The constructor interrogates the relevant system properties using the specified Catalog Manager and initializes the catalog data structures.

Method Details

addDelegate

protected void addDelegate(CatalogEntry entry)
Add to the current list of delegated catalogs.

This method always constructs the localDelegate vector so that it is ordered by length of partial public identifier.

Parameters:
entry - The DELEGATE catalog entry

addEntry

public void addEntry(CatalogEntry entry)
Cleanup and process a Catalog entry.

This method processes each Catalog entry, changing mapped relative system identifiers into absolute ones (based on the current base URI), and maintaining other information about the current catalog.

Parameters:
entry - The CatalogEntry to process.

addReader

public void addReader(String mimeType,
                      CatalogReader reader)
Add a new CatalogReader to the Catalog.

This method allows you to add a new CatalogReader to the catalog. The reader will be associated with the specified mimeType. You can only have one reader per mimeType.

In the absence of a mimeType (e.g., when reading a catalog directly from a file on the local system), the readers are attempted in the order that you add them to the Catalog.

Note that subordinate catalogs (created by CATALOG or DELEGATE* entries) get a copy of the set of readers present in the primary catalog when they are created. Readers added subsequently will not be available. For this reason, it is best to add all of the readers before the first call to parse a catalog.

Parameters:
mimeType - The MIME type associated with this reader.
reader - The CatalogReader to use.

copyReaders

protected void copyReaders(Catalog newCatalog)
Copies the reader list from the current Catalog to a new Catalog.

This method is used internally when constructing a new catalog. It copies the current reader associations over to the new catalog.

Parameters:
newCatalog - The new Catalog.

encodedByte

protected String encodedByte(int b)
Perform %-encoding on a single byte.
Parameters:
b - The 8-bit integer that represents th byte. (Bytes are signed but encoding needs to look at the bytes unsigned.)
Returns:
The %-encoded string for the byte in question.

fixSlashes

protected String fixSlashes(String sysid)
Replace backslashes with forward slashes. (URLs always use forward slashes.)
Parameters:
sysid - The input system identifier.
Returns:
The same system identifier with backslashes turned into forward slashes.

getCatalogManager

public CatalogManager getCatalogManager()
Return the CatalogManager used by this catalog.

getCurrentBase

public String getCurrentBase()
Returns the current base URI.

getDefaultOverride

public String getDefaultOverride()
Returns the default override setting associated with this catalog.

All catalog files loaded by this catalog will have the initial override setting specified by this default.


loadSystemCatalogs

public void loadSystemCatalogs()
            throws MalformedURLException,
                   IOException
Load the system catalog files.

The method adds all of the catalogs specified in the xml.catalog.files property to the Catalog list.


makeAbsolute

protected String makeAbsolute(String sysid)
Construct an absolute URI from a relative one, using the current base URI.
Parameters:
sysid - The (possibly relative) system identifier

newCatalog

protected Catalog newCatalog()
Create a new Catalog object.

This method constructs a new instance of the running Catalog class (which might be a subtype of org.apache.xml.resolver.Catalog). All new catalogs are managed by the same CatalogManager.

N.B. All Catalog subtypes should call newCatalog() to construct a new Catalog. Do not simply use "new Subclass()" since that will confuse future subclasses.


normalizeURI

protected String normalizeURI(String uriref)
Perform character normalization on a URI reference.
Parameters:
uriref - The URI reference
Returns:
The normalized URI reference.

parseAllCatalogs

public void parseAllCatalogs()
            throws MalformedURLException,
                   IOException
Parse all subordinate catalogs.

This method recursively parses all of the subordinate catalogs. If this method does not throw an exception, you can be confident that no subsequent call to any resolve*() method will either, with two possible exceptions:

  1. Delegated catalogs are re-parsed each time they are needed (because a variable list of them may be needed in each case, depending on the length of the matching partial public identifier).

    But they are parsed by this method, so as long as they don't change or disappear while the program is running, they shouldn't generate errors later if they don't generate errors now.

  2. If you add new catalogs with parseCatalog, they won't be loaded until they are needed or until you call parseAllCatalogs again.

On the other hand, if you don't call this method, you may successfully parse documents without having to load all possible catalogs.


parseCatalog

public void parseCatalog(String fileName)
            throws MalformedURLException,
                   IOException
Parse a catalog file, augmenting internal data structures.
Parameters:
fileName - The filename of the catalog file to process

parseCatalog

public void parseCatalog(String mimeType,
                         InputStream is)
            throws IOException,
                   CatalogException
Parse a catalog file, augmenting internal data structures.

Catalogs retrieved over the net may have an associated MIME type. The MIME type can be used to select an appropriate reader.

Parameters:
mimeType - The MIME type of the catalog file.
is - The InputStream from which the catalog should be read
Throws:
CatalogException - Failed to load catalog mimeType.

parseCatalog

public void parseCatalog(URL aUrl)
            throws IOException
Parse a catalog document, augmenting internal data structures.

This method supports catalog files stored in jar files: e.g., jar:file:///path/to/filename.jar!/path/to/catalog.xml". That URI doesn't survive transmogrification through the URI processing that the parseCatalog(String) performs and passing it as an input stream doesn't set the base URI appropriately.

Written by Stefan Wachter (2002-09-26)

Parameters:
aUrl - The URL of the catalog document to process

parseCatalogFile

protected void parseCatalogFile(String fileName)
            throws MalformedURLException,
                   IOException,
                   CatalogException
Parse a single catalog file, augmenting internal data structures.
Parameters:
fileName - The filename of the catalog file to process

parsePendingCatalogs

protected void parsePendingCatalogs()
            throws MalformedURLException,
                   IOException
Parse all of the pending catalogs.

Catalogs may refer to other catalogs, this method parses all of the currently pending catalog files.


resolveDoctype

public String resolveDoctype(String entityName,
                             String publicId,
                             String systemId)
            throws MalformedURLException,
                   IOException
Return the applicable DOCTYPE system identifier.
Parameters:
entityName - The name of the entity (element) for which a doctype is required.
publicId - The nominal public identifier for the doctype (as provided in the source document).
systemId - The nominal system identifier for the doctype (as provided in the source document).
Returns:
The system identifier to use for the doctype.

resolveDocument

public String resolveDocument()
            throws MalformedURLException,
                   IOException
Return the applicable DOCUMENT entry.
Returns:
The system identifier to use for the doctype.

resolveEntity

public String resolveEntity(String entityName,
                            String publicId,
                            String systemId)
            throws MalformedURLException,
                   IOException
Return the applicable ENTITY system identifier.
Parameters:
entityName - The name of the entity for which a system identifier is required.
publicId - The nominal public identifier for the entity (as provided in the source document).
systemId - The nominal system identifier for the entity (as provided in the source document).
Returns:
The system identifier to use for the entity.

resolveLocalPublic

protected String resolveLocalPublic(int entityType,
                                    String entityName,
                                    String publicId,
                                    String systemId)
            throws MalformedURLException,
                   IOException
Return the applicable PUBLIC or SYSTEM identifier.

This method searches the Catalog and returns the system identifier specified for the given system or public identifiers. If no appropriate PUBLIC or SYSTEM entry is found in the Catalog, delegated Catalogs are interrogated.

There are four possible cases:

  • If the system identifier provided matches a SYSTEM entry in the current catalog, the SYSTEM entry is returned.
  • If the system identifier is not null, the PUBLIC entries that were encountered when OVERRIDE YES was in effect are interrogated and the first matching entry is returned.
  • If the system identifier is null, then all of the PUBLIC entries are interrogated and the first matching entry is returned. This may not be the same as the preceding case, if some PUBLIC entries are encountered when OVERRIDE NO is in effect. In XML, the only place where a public identifier may occur without a system identifier is in a notation declaration.
  • Finally, if the public identifier matches one of the partial public identifiers specified in a DELEGATE* entry in the Catalog, the delegated catalog is interrogated. The first time that the delegated catalog is required, it will be retrieved and parsed. It is subsequently cached.
Parameters:
entityType - The CatalogEntry type for which this query is being conducted. This is necessary in order to do the approprate query on a delegated catalog.
entityName - The name of the entity being searched for, if appropriate.
publicId - The public identifier of the entity in question.
systemId - The nominal system identifier for the entity in question (as provided in the source document).
Returns:
The system identifier to use. Note that the nominal system identifier is not returned if a match is not found in the catalog, instead null is returned to indicate that no match was found.

resolveLocalSystem

protected String resolveLocalSystem(String systemId)
            throws MalformedURLException,
                   IOException
Return the applicable SYSTEM system identifier in this catalog.

If a SYSTEM entry exists in the catalog file for the system ID specified, return the mapped value.

Parameters:
systemId - The system ID to locate in the catalog
Returns:
The mapped system identifier or null

resolveLocalURI

protected String resolveLocalURI(String uri)
            throws MalformedURLException,
                   IOException
Return the applicable URI in this catalog.

If a URI entry exists in the catalog file for the URI specified, return the mapped value.

Parameters:
uri - The URI to locate in the catalog
Returns:
The mapped URI or null

resolveNotation

public String resolveNotation(String notationName,
                              String publicId,
                              String systemId)
            throws MalformedURLException,
                   IOException
Return the applicable NOTATION system identifier.
Parameters:
notationName - The name of the notation for which a doctype is required.
publicId - The nominal public identifier for the notation (as provided in the source document).
systemId - The nominal system identifier for the notation (as provided in the source document).
Returns:
The system identifier to use for the notation.

resolvePublic

public String resolvePublic(String publicId,
                            String systemId)
            throws MalformedURLException,
                   IOException
Return the applicable PUBLIC or SYSTEM identifier.

This method searches the Catalog and returns the system identifier specified for the given system or public identifiers. If no appropriate PUBLIC or SYSTEM entry is found in the Catalog, null is returned.

Parameters:
publicId - The public identifier to locate in the catalog. Public identifiers are normalized before comparison.
systemId - The nominal system identifier for the entity in question (as provided in the source document).
Returns:
The system identifier to use. Note that the nominal system identifier is not returned if a match is not found in the catalog, instead null is returned to indicate that no match was found.

resolveSubordinateCatalogs

protected String resolveSubordinateCatalogs(int entityType,
                                            String entityName,
                                            String publicId,
                                            String systemId)
            throws MalformedURLException,
                   IOException
Search the subordinate catalogs, in order, looking for a match.

This method searches the Catalog and returns the system identifier specified for the given entity type with the given name, public, and system identifiers. In some contexts, these may be null.

Parameters:
entityType - The CatalogEntry type for which this query is being conducted. This is necessary in order to do the approprate query on a subordinate catalog.
entityName - The name of the entity being searched for, if appropriate.
publicId - The public identifier of the entity in question (as provided in the source document).
systemId - The nominal system identifier for the entity in question (as provided in the source document). This parameter is overloaded for the URI entry type.
Returns:
The system identifier to use. Note that the nominal system identifier is not returned if a match is not found in the catalog, instead null is returned to indicate that no match was found.

resolveSystem

public String resolveSystem(String systemId)
            throws MalformedURLException,
                   IOException
Return the applicable SYSTEM system identifier.

If a SYSTEM entry exists in the Catalog for the system ID specified, return the mapped value.

On Windows-based operating systems, the comparison between the system identifier provided and the SYSTEM entries in the Catalog is case-insensitive.

Parameters:
systemId - The system ID to locate in the catalog.
Returns:
The resolved system identifier.

resolveURI

public String resolveURI(String uri)
            throws MalformedURLException,
                   IOException
Return the applicable URI.

If a URI entry exists in the Catalog for the URI specified, return the mapped value.

URI comparison is case sensitive.

Parameters:
uri - The URI to locate in the catalog.
Returns:
The resolved URI.

setCatalogManager

public void setCatalogManager(CatalogManager manager)
Establish the CatalogManager used by this catalog.

setupReaders

public void setupReaders()
Setup readers.

unknownEntry

public void unknownEntry(Vector strings)
Handle unknown CatalogEntry types.

This method exists to allow subclasses to deal with unknown entry types.


Copyright B) 2001-2003 Apache Software Foundation. All Rights Reserved.