Interface CatalogResolver
- All Superinterfaces:
EntityResolver,LSResourceResolver,URIResolver,XMLResolver
EntityResolver,
StAX XMLResolver,
DOM LS LSResourceResolver used by Schema Validation, and
Transform URIResolver, and resolves
external references using catalogs.
The
Catalog Standard distinguished external identifiers from uri entries
as being used to solely identify DTDs, while uri entries for
other resources such as stylesheets and schema. The Java APIs, such as
XMLResolver and LSResourceResolver
however, make no such distinction.
In consistent with the existing Java API, this CatalogResolver recognizes a
system identifier as a URI and will search both system and uri
entries in a catalog in order to find a matching entry.
The search is started in the current catalog. If a match is found, no further attempt will be made. Only if there is no match in the current catalog, will alternate catalogs including delegate and next catalogs be considered.
Search Order
The resolver will first search the system-type of entries with the specifiedsystemId. The system entries include system,
rewriteSystem and systemSuffix entries.
If no match is found, public entries may be searched in accordance with
the prefer attribute.
The prefer attribute: if the prefer is public,
and there is no match found through the system entries, public entries
will be considered. If it is not specified, the prefer is public
by default (Note that by the OASIS standard, system entries will always
be considered before public entries. Prefer public means that public entries
will be matched when both system and public identifiers are specified.
In general therefore, prefer public is recommended.)
If no match is found with the systemId and public identifier,
the resolver will continue searching uri entries
with the specified systemId or href. The uri entries
include uri, rewriteURI, and uriSuffix entries.
Error Handling
The interfaces that the CatalogResolver extend specified checked exceptions, including:-
SAXExceptionandIOExceptionbyEntityResolver.resolveEntity(java.lang.String, java.lang.String) -
XMLStreamExceptionbyXMLResolver.resolveEntity(java.lang.String, java.lang.String, java.lang.String, java.lang.String) -
TransformerExceptionbyURIResolver.resolve(java.lang.String, java.lang.String)
The CatalogResolver however, will throw CatalogException
only when javax.xml.catalog.resolve is specified as strict.
For applications that expect to handle the checked Exceptions, it may be
necessary to use a custom resolver to wrap the CatalogResolver or implement it
with a Catalog object.
- Since:
- 9
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Nested Class Summary
Nested ClassesModifier and TypeInterfaceDescriptionstatic enumDefines the actions that a CatalogResolver may take when it is unable to resolve an external reference. -
Method Summary
Modifier and TypeMethodDescriptionImplements URIResolver.resolveEntity(String publicId, String systemId) ImplementsEntityResolver.resolveEntity(String publicId, String systemId, String baseUri, String namespace) ImplementsXMLResolver.ImplementsLSResourceResolver.
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Method Details
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resolveEntity
ImplementsEntityResolver. The method searches through the catalog entries in the main and alternative catalogs to attempt to find a match with the specifiedpublicIdor systemId.- Specified by:
resolveEntityin interfaceEntityResolver- Parameters:
publicId- the public identifier of the external entity being referenced, or null if none was suppliedsystemId- the system identifier of the external entity being referenced. A system identifier is required on all external entities. XML requires a system identifier on all external entities, so this value is always specified.- Returns:
- a
InputSourceobject if a mapping is found. If no mapping is found, returns aInputSourceobject containing an emptyReaderif thejavax.xml.catalog.resolveproperty is set toignore; returns null if thejavax.xml.catalog.resolveproperty is set tocontinue. - Throws:
CatalogException- if no mapping is found andjavax.xml.catalog.resolveis specified asstrict- See Also:
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resolve
Implements URIResolver. The method searches through the catalog entries in the main and alternative catalogs to attempt to find a match with the specifiedhrefattribute. Thehrefattribute will be used literally, with no attempt to be made absolute to thebase.If the value is a URN, the
hrefattribute is recognized as apublicId, and used to searchpublicentries. If the value is a URI, it is taken as asystemId, and used to search bothsystemandurientries.- Specified by:
resolvein interfaceURIResolver- Parameters:
href- the href attribute that specifies the URI of a style sheet, which may be relative or absolutebase- The base URI against which the href attribute will be made absolute if the absolute URI is required- Returns:
- a
Sourceobject if a mapping is found. If no mapping is found, returns an emptySourceobject if thejavax.xml.catalog.resolveproperty is set toignore; returns aSourceobject with the original URI (href, or href resolved with base if base is not null) if thejavax.xml.catalog.resolveproperty is set tocontinue. - Throws:
CatalogException- if no mapping is found andjavax.xml.catalog.resolveis specified asstrict
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resolveEntity
ImplementsXMLResolver. For the purpose of resolvingpublicIdandsystemId, this method is equivalent toresolveEntity(java.lang.String, java.lang.String).The
systemIdwill be used literally, with no attempt to be made absolute to thebaseUri. ThebaseUriandnamespaceare not used in the search for a match in a catalog. However, a relativesystemIdin an xml source may have been made absolute by the parser with thebaseURI, thus making it unable to find asystementry. In such a case, asystemSuffixentry is recommended over asystementry.- Specified by:
resolveEntityin interfaceXMLResolver- Parameters:
publicId- the public identifier of the external entity being referenced, or null if none was suppliedsystemId- the system identifier of the external entity being referenced. A system identifier is required on all external entities. XML requires a system identifier on all external entities, so this value is always specified.baseUri- the absolute base URI, not used by the CatalogResolvernamespace- the namespace of the entity to resolve, not used by the CatalogResolver.- Returns:
- an
InputStreamobject if a mapping is found; null if no mapping is found and thejavax.xml.catalog.resolveproperty is set tocontinueorignore. Note that for XMLResolver, it is not possible to ignore a reference,ignoreis therefore treated the same ascontinue. - Throws:
CatalogException- if no mapping is found andjavax.xml.catalog.resolveis specified asstrict
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resolveResource
LSInput resolveResource(String type, String namespaceUri, String publicId, String systemId, String baseUri) ImplementsLSResourceResolver. For the purpose of resolvingpublicIdandsystemId, this method is equivalent toresolveEntity(java.lang.String, java.lang.String).The
systemIdwill be used literally, with no attempt to be made absolute to thebaseUri. ThebaseUri,namespaceUriandtypeare not used in the search for a match in a catalog. However, a relativesystemIdin a source may have been made absolute by the parser with thebaseURI, thus making it unable to find asystementry. In such a case, asystemSuffixentry is recommended over asystementry.- Specified by:
resolveResourcein interfaceLSResourceResolver- Parameters:
type- the type of the resource being resolved, not used by the CatalogResolvernamespaceUri- the namespace of the resource being resolved, not used by the CatalogResolverpublicId- the public identifier of the external entity being referenced, ornullif no public identifier was supplied or if the resource is not an entity.systemId- the system identifier, a URI reference of the external resource being referencedbaseUri- the absolute base URI, not used by the CatalogResolver- Returns:
- a
LSInputobject if a mapping is found; null if no mapping is found and thejavax.xml.catalog.resolveproperty is set tocontinueorignore. Note that forLSResourceResolver, it is not possible to ignore a reference,ignoreis therefore treated the same ascontinue. - Throws:
CatalogException- if no mapping is found andjavax.xml.catalog.resolveis specified asstrict
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