org.apache.xerces.util

Class XMLCatalogResolver

public class XMLCatalogResolver extends Object implements XMLEntityResolver, EntityResolver2, LSResourceResolver

The catalog resolver handles the resolution of external identifiers and URI references through XML catalogs. This component supports XML catalogs defined by the OASIS XML Catalogs Specification. It encapsulates the XML Commons resolver. An instance of this class may be registered on the parser as a SAX entity resolver, as a DOM LSResourceResolver or as an XNI entity resolver by setting the property (http://apache.org/xml/properties/internal/entity-resolver).

It is intended that this class may be used standalone to perform catalog resolution outside of a parsing context. It may be shared between several parsers and the application.

Version: $Id: XMLCatalogResolver.java,v 1.8 2005/05/02 21:44:37 mrglavas Exp $

Author: Michael Glavassevich, IBM

Constructor Summary
XMLCatalogResolver()

Constructs a catalog resolver with a default configuration.

XMLCatalogResolver(String[] catalogs)

Constructs a catalog resolver with the given list of entry files.

XMLCatalogResolver(String[] catalogs, boolean preferPublic)

Constructs a catalog resolver with the given list of entry files and the preference for whether system or public matches are preferred.

Method Summary
voidclear()

Forces the cache of catalog mappings to be cleared.

String[]getCatalogList()

Returns the initial list of catalog entry files.

InputSourcegetExternalSubset(String name, String baseURI)

Locates an external subset for documents which do not explicitly provide one.

booleangetPreferPublic()

Returns the preference for whether system or public matches are preferred.

booleangetUseLiteralSystemId()

Returns the preference for whether the literal system identifier should be used when resolving system identifiers when both it and the expanded system identifier are available.

InputSourceresolveEntity(String publicId, String systemId)

Resolves an external entity.

InputSourceresolveEntity(String name, String publicId, String baseURI, String systemId)

Resolves an external entity.

XMLInputSourceresolveEntity(XMLResourceIdentifier resourceIdentifier)

Resolves an external entity.

StringresolveIdentifier(XMLResourceIdentifier resourceIdentifier)

Resolves an identifier using the catalog.

StringresolvePublic(String publicId, String systemId)

Returns the URI mapping in the catalog for the given external identifier or null if no mapping exists.

LSInputresolveResource(String type, String namespaceURI, String publicId, String systemId, String baseURI)

Resolves a resource using the catalog.

StringresolveSystem(String systemId)

Returns the URI mapping in the catalog for the given external identifier or null if no mapping exists.

StringresolveURI(String uri)

Returns the URI mapping in the catalog for the given URI reference or null if no mapping exists.

voidsetCatalogList(String[] catalogs)

Sets the initial list of catalog entry files.

voidsetPreferPublic(boolean preferPublic)

Sets the preference for whether system or public matches are preferred.

voidsetUseLiteralSystemId(boolean useLiteralSystemId)

Sets the preference for whether the literal system identifier should be used when resolving system identifiers when both it and the expanded system identifier are available.

The literal system identifier is the URI as it was provided before absolutization.

Constructor Detail

XMLCatalogResolver

public XMLCatalogResolver()

Constructs a catalog resolver with a default configuration.

XMLCatalogResolver

public XMLCatalogResolver(String[] catalogs)

Constructs a catalog resolver with the given list of entry files.

Parameters: catalogs an ordered array list of absolute URIs

XMLCatalogResolver

public XMLCatalogResolver(String[] catalogs, boolean preferPublic)

Constructs a catalog resolver with the given list of entry files and the preference for whether system or public matches are preferred.

Parameters: catalogs an ordered array list of absolute URIs preferPublic the prefer public setting

Method Detail

clear

public final void clear()

Forces the cache of catalog mappings to be cleared.

getCatalogList

public final String[] getCatalogList()

Returns the initial list of catalog entry files.

Returns: the initial list of catalog entry files

getExternalSubset

public InputSource getExternalSubset(String name, String baseURI)

Locates an external subset for documents which do not explicitly provide one. This method always returns null. It should be overrided if other behaviour is required.

Parameters: name the identifier of the document root element baseURI the document's base URI

Throws: SAXException any SAX exception, possibly wrapping another exception IOException thrown if some i/o error occurs

getPreferPublic

public final boolean getPreferPublic()

Returns the preference for whether system or public matches are preferred. This is used in the absence of any occurence of the prefer attribute on the catalog entry of a catalog. If this property has not yet been explicitly set its value is true.

Returns: the prefer public setting

getUseLiteralSystemId

public final boolean getUseLiteralSystemId()

Returns the preference for whether the literal system identifier should be used when resolving system identifiers when both it and the expanded system identifier are available. If this property has not yet been explicitly set its value is true.

Returns: the preference for using literal system identifers for catalog resolution

See Also: XMLCatalogResolver

resolveEntity

public InputSource resolveEntity(String publicId, String systemId)

Resolves an external entity. If the entity cannot be resolved, this method should return null. This method returns an input source if an entry was found in the catalog for the given external identifier. It should be overrided if other behaviour is required.

Parameters: publicId the public identifier, or null if none was supplied systemId the system identifier

Throws: SAXException any SAX exception, possibly wrapping another exception IOException thrown if some i/o error occurs

resolveEntity

public InputSource resolveEntity(String name, String publicId, String baseURI, String systemId)

Resolves an external entity. If the entity cannot be resolved, this method should return null. This method returns an input source if an entry was found in the catalog for the given external identifier. It should be overrided if other behaviour is required.

Parameters: name the identifier of the external entity publicId the public identifier, or null if none was supplied baseURI the URI with respect to which relative systemIDs are interpreted. systemId the system identifier

Throws: SAXException any SAX exception, possibly wrapping another exception IOException thrown if some i/o error occurs

resolveEntity

public XMLInputSource resolveEntity(XMLResourceIdentifier resourceIdentifier)

Resolves an external entity. If the entity cannot be resolved, this method should return null. This method only calls resolveIdentifier and returns an input source if an entry was found in the catalog. It should be overrided if other behaviour is required.

Parameters: resourceIdentifier location of the XML resource to resolve

Throws: XNIException thrown on general error IOException thrown if some i/o error occurs

resolveIdentifier

public String resolveIdentifier(XMLResourceIdentifier resourceIdentifier)

Resolves an identifier using the catalog. This method interprets that the namespace of the identifier corresponds to uri entries in the catalog. Where both a namespace and an external identifier exist, the namespace takes precedence.

Parameters: resourceIdentifier the identifier to resolve

Throws: XNIException thrown on general error IOException thrown if some i/o error occurs

resolvePublic

public final String resolvePublic(String publicId, String systemId)

Returns the URI mapping in the catalog for the given external identifier or null if no mapping exists. Public identifiers are normalized before comparison.

Parameters: publicId the public identifier to locate in the catalog systemId the system identifier to locate in the catalog

Returns: the mapped URI or null if no mapping was found in the catalog

Throws: IOException if an i/o error occurred while reading the catalog

resolveResource

public LSInput resolveResource(String type, String namespaceURI, String publicId, String systemId, String baseURI)

Resolves a resource using the catalog. This method interprets that the namespace URI corresponds to uri entries in the catalog. Where both a namespace and an external identifier exist, the namespace takes precedence.

Parameters: type the type of the resource being resolved namespaceURI the namespace of the resource being resolved, or null if none was supplied publicId the public identifier of the resource being resolved, or null if none was supplied systemId the system identifier of the resource being resolved, or null if none was supplied baseURI the absolute base URI of the resource being parsed, or null if there is no base URI

resolveSystem

public final String resolveSystem(String systemId)

Returns the URI mapping in the catalog for the given external identifier or null if no mapping exists. If the system identifier is an URN in the publicid namespace it is converted into a public identifier by URN "unwrapping" as specified in the XML Catalogs specification.

Parameters: systemId the system identifier to locate in the catalog

Returns: the mapped URI or null if no mapping was found in the catalog

Throws: IOException if an i/o error occurred while reading the catalog

resolveURI

public final String resolveURI(String uri)

Returns the URI mapping in the catalog for the given URI reference or null if no mapping exists. URI comparison is case sensitive. If the URI reference is an URN in the publicid namespace it is converted into a public identifier by URN "unwrapping" as specified in the XML Catalogs specification and then resolution is performed following the semantics of external identifier resolution.

Parameters: uri the URI to locate in the catalog

Returns: the mapped URI or null if no mapping was found in the catalog

Throws: IOException if an i/o error occurred while reading the catalog

setCatalogList

public final void setCatalogList(String[] catalogs)

Sets the initial list of catalog entry files. If there were any catalog mappings cached from the previous list they will be replaced by catalog mappings from the new list the next time the catalog is queried.

Parameters: catalogs an ordered array list of absolute URIs

setPreferPublic

public final void setPreferPublic(boolean preferPublic)

Sets the preference for whether system or public matches are preferred. This is used in the absence of any occurence of the prefer attribute on the catalog entry of a catalog.

Parameters: preferPublic the prefer public setting

setUseLiteralSystemId

public final void setUseLiteralSystemId(boolean useLiteralSystemId)

Sets the preference for whether the literal system identifier should be used when resolving system identifiers when both it and the expanded system identifier are available.

The literal system identifier is the URI as it was provided before absolutization. It may be embedded within an entity. It may be provided externally or it may be the result of redirection. For example, redirection may have come from the protocol level through HTTP or from an application's entity resolver.

The expanded system identifier is an absolute URI which is the result of resolving the literal system identifier against a base URI.

Parameters: useLiteralSystemId the preference for using literal system identifers for catalog resolution

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