org.apache.xml.resolver
Class Catalog

java.lang.Object
  org.apache.xml.resolver.Catalog

Direct Known 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:

• BASE changes the base URI for resolving relative system identifiers. The initial base URI is the URI of the location of the catalog (which is, in turn, relative to the location of the current working directory at startup, as returned by the user.dir system property).
• CATALOG processes other catalog files. An included catalog occurs logically at the end of the including catalog.
• DELEGATE_PUBLIC specifies alternate catalogs for some public identifiers. The delegated catalogs are not loaded until they are needed, but they are cached once loaded.
• DELEGATE_SYSTEM specifies alternate catalogs for some system identifiers. The delegated catalogs are not loaded until they are needed, but they are cached once loaded.
• DELEGATE_URI specifies alternate catalogs for some URIs. The delegated catalogs are not loaded until they are needed, but they are cached once loaded.
• REWRITE_SYSTEM specifies alternate prefix for a system identifier.
• REWRITE_URI specifies alternate prefix for a URI.
• DOCTYPE associates the names of root elements with URIs. (In other words, an XML processor might infer the doctype of an XML document that does not include a doctype declaration by looking for the DOCTYPE entry in the catalog which matches the name of the root element of the document.)
• DOCUMENT provides a default document.
• DTDDECL recognized and silently ignored. Not relevant for XML.
• ENTITY associates entity names with URIs.
• LINKTYPE recognized and silently ignored. Not relevant for XML.
• NOTATION associates notation names with URIs.
• OVERRIDE changes the override behavior. Initial behavior is set by the system property xml.catalog.override. The default initial behavior is 'YES', that is, entries in the catalog override system identifiers specified in the document.
• PUBLIC maps a public identifier to a system identifier.
• SGMLDECL recognized and silently ignored. Not relevant for XML.
• SYSTEM maps a system identifier to another system identifier.
• URI maps a URI to another URI.

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(java.lang.String) method.

Change Log:

2.0

Rewrite to use CatalogReaders.

1.1

Allow quoted components in xml.catalog.files so that URLs containing colons can be used on Unix. The string passed to xml.catalog.files can now have the form:

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

(Where ":" is the separater character in this example.)

If an unquoted path contains an embedded double or single quote character, no special processig is performed on that character. No path can contain separater characters, double, and single quotes simultaneously.

Fix bug in calculation of BASE entries: if a catalog contains multiple BASE entries, each is relative to the preceding base, not the default base URI of the catalog.

1.0.1

Fixed a bug in the calculation of the list of subordinate catalogs. This bug caused an infinite loop where parsing would alternately process two catalogs indefinitely.

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

protected URL	base The base URI for relative system identifiers in the catalog.
static int	BASE The BASE Catalog Entry type
static int	CATALOG The CATALOG Catalog Entry type
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 Vector	catalogs A vector of Catalogs.
protected boolean	default_override The default initial override setting.
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
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.
static int	NOTATION The NOTATION Catalog Entry type
static int	OVERRIDE The OVERRIDE Catalog Entry type
static int	PUBLIC The PUBLIC Catalog Entry type
protected Vector	readerArr A vector of CatalogReaders.
protected Hashtable	readerMap A hash of CatalogReaders.
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	URI The URI Catalog Entry type

Constructor Summary

Catalog()
Constructs an empty Catalog.

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 This method is used internally when constructing a new catalog.
protected String	encodedByte(int b) Perform %-encoding on a single byte.
protected String	fixSlashes(String sysid) Replace backslashes with forward slashes.
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 Catalogs retrieved over the net may have an associated MIME type.
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 This method searches the Catalog and returns the system identifier specified for the given system or public identifiers.
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 If a SYSTEM entry exists in the Catalog for the system ID specified, return the mapped value.
String	resolveURI(String uri) Return the applicable URI If a URI entry exists in the Catalog for the URI specified, return the mapped value.
void	setupReaders() Setup readers.
void	unknownEntry(Vector strings) Handle unknown CatalogEntry types.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

BASE

public static final int BASE

The BASE Catalog Entry type

CATALOG

public static final int CATALOG

The CATALOG Catalog Entry type

DOCUMENT

public static final int DOCUMENT

The DOCUMENT Catalog Entry type

OVERRIDE

public static final int OVERRIDE

The OVERRIDE Catalog Entry type

SGMLDECL

public static final int SGMLDECL

The SGMLDECL 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

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

PUBLIC

public static final int PUBLIC

The PUBLIC Catalog Entry type

SYSTEM

public static final int SYSTEM

The SYSTEM Catalog Entry type

URI

public static final int URI

The URI 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

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.

default_override

protected boolean default_override

The default initial override setting.

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.

See Also:

loadSystemCatalogs(), localCatalogFiles

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.

See Also:

catalogFiles

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.

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.

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.

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.

Constructor Detail

Catalog

public Catalog()

Constructs an empty Catalog.

The constructor interrogates the relevant system properties and initializes the catalog data structures.

Method Detail

setupReaders

public void setupReaders()

Setup readers.

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.

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).

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.

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.

Throws:

MalformedURLException - One of the system catalogs is identified with a filename that is not a valid URL.

IOException - One of the system catalogs cannot be read.

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

Throws:

MalformedURLException - The fileName cannot be turned into a valid URL.

IOException - Error reading catalog file.

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.

IOException - Error reading catalog file.

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.

Throws:

MalformedURLException

IOException

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

Throws:

MalformedURLException - The fileName cannot be turned into a valid URL.

IOException - Error reading catalog file.

CatalogException

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.

unknownEntry

public void unknownEntry(Vector strings)

Handle unknown CatalogEntry types.

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

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.

Throws:

MalformedURLException - The filename (URL) for a subordinate or delegated catalog is not a valid URL.

IOException - Error reading some subordinate or delegated catalog file.

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.

Throws:

MalformedURLException - The formal system identifier of a subordinate catalog cannot be turned into a valid URL.

IOException - Error reading subordinate catalog file.

resolveDocument

public String resolveDocument()
                       throws MalformedURLException,
                              IOException

Return the applicable DOCUMENT entry.

Returns:

The system identifier to use for the doctype.

Throws:

MalformedURLException - The formal system identifier of a subordinate catalog cannot be turned into a valid URL.

IOException - Error reading subordinate catalog file.

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.

Throws:

MalformedURLException - The formal system identifier of a subordinate catalog cannot be turned into a valid URL.

IOException - Error reading subordinate catalog file.

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.

Throws:

MalformedURLException - The formal system identifier of a subordinate catalog cannot be turned into a valid URL.

IOException - Error reading subordinate catalog file.

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.

Throws:

MalformedURLException - The formal system identifier of a subordinate catalog cannot be turned into a valid URL.

IOException - Error reading subordinate catalog file.

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.

Throws:

MalformedURLException - The formal system identifier of a delegated catalog cannot be turned into a valid URL.

IOException - Error reading delegated catalog file.

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.

Throws:

MalformedURLException - The formal system identifier of a subordinate catalog cannot be turned into a valid URL.

IOException - Error reading subordinate catalog file.

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

Throws:

MalformedURLException

IOException

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.

Throws:

MalformedURLException - The system identifier of a subordinate catalog cannot be turned into a valid URL.

IOException - Error reading subordinate catalog file.

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

Throws:

MalformedURLException

IOException

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.

Throws:

MalformedURLException - The formal system identifier of a delegated catalog cannot be turned into a valid URL.

IOException - Error reading delegated catalog file.

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.

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

Returns:

The system identifier made absolute with respect to the current base.

normalizeURI

protected String normalizeURI(String uriref)

Perform character normalization on a URI reference.

Parameters:

uriref - The URI reference

Returns:

The normalized URI reference.

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.

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