Interface CatalogResolver

All Superinterfaces:: EntityResolver, LSResourceResolver, URIResolver, XMLResolver

public interface CatalogResolver
extends EntityResolver, XMLResolver, URIResolver, LSResourceResolver

A Catalog Resolver that implements SAX 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 specified systemId. 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:

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

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Source`	`resolve(String href, String base)`	Implements URIResolver.
`InputSource`	`resolveEntity(String publicId, String systemId)`	Implements `EntityResolver`.
`InputStream`	`resolveEntity(String publicId, String systemId, String baseUri, String namespace)`	Implements `XMLResolver`.
`LSInput`	`resolveResource(String type, String namespaceUri, String publicId, String systemId, String baseUri)`	Implements `LSResourceResolver`.

Method Detail

resolveEntity

InputSource resolveEntity(String publicId,
                          String systemId)

Implements EntityResolver. The method searches through the catalog entries in the main and alternative catalogs to attempt to find a match with the specified publicId or systemId.

Specified by:: resolveEntity in interface EntityResolver
Parameters:: publicId - the public identifier of the external entity being referenced, or null if none was supplied; systemId - 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 InputSource object if a mapping is found. If no mapping is found, returns a InputSource object containing an empty Reader if the javax.xml.catalog.resolve property is set to ignore; returns null if the javax.xml.catalog.resolve property is set to continue.
Throws:: CatalogException - if no mapping is found and javax.xml.catalog.resolve is specified as strict
See Also:: InputSource

resolve

Source resolve(String href,
               String base)

Implements URIResolver. The method searches through the catalog entries in the main and alternative catalogs to attempt to find a match with the specified href attribute. The href attribute will be used literally, with no attempt to be made absolute to the base.

If the value is a URN, the href attribute is recognized as a publicId, and used to search public entries. If the value is a URI, it is taken as a systemId, and used to search both system and uri entries.

Specified by:: resolve in interface URIResolver
Parameters:: href - the href attribute that specifies the URI of a style sheet, which may be relative or absolute; base - The base URI against which the href attribute will be made absolute if the absolute URI is required
Returns:: a Source object if a mapping is found. If no mapping is found, returns an empty Source object if the javax.xml.catalog.resolve property is set to ignore; returns a Source object with the original URI (href, or href resolved with base if base is not null) if the javax.xml.catalog.resolve property is set to continue.
Throws:: CatalogException - if no mapping is found and javax.xml.catalog.resolve is specified as strict

resolveEntity

InputStream resolveEntity(String publicId,
                          String systemId,
                          String baseUri,
                          String namespace)

Implements XMLResolver. For the purpose of resolving publicId and systemId, this method is equivalent to resolveEntity(java.lang.String, java.lang.String).

The systemId will be used literally, with no attempt to be made absolute to the baseUri. The baseUri and namespace are not used in the search for a match in a catalog. However, a relative systemId in an xml source may have been made absolute by the parser with the baseURI, thus making it unable to find a system entry. In such a case, a systemSuffix entry is recommended over a system entry.

Specified by:: resolveEntity in interface XMLResolver
Parameters:: publicId - the public identifier of the external entity being referenced, or null if none was supplied; systemId - 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 CatalogResolver; namespace - the namespace of the entity to resolve, not used by the CatalogResolver.
Returns:: an InputStream object if a mapping is found; null if no mapping is found and the javax.xml.catalog.resolve property is set to continue or ignore. Note that for XMLResolver, it is not possible to ignore a reference, ignore is therefore treated the same as continue.
Throws:: CatalogException - if no mapping is found and javax.xml.catalog.resolve is specified as strict

resolveResource

LSInput resolveResource(String type,
                        String namespaceUri,
                        String publicId,
                        String systemId,
                        String baseUri)

Implements LSResourceResolver. For the purpose of resolving publicId and systemId, this method is equivalent to resolveEntity(java.lang.String, java.lang.String).

The systemId will be used literally, with no attempt to be made absolute to the baseUri. The baseUri, namespaceUri and type are not used in the search for a match in a catalog. However, a relative systemId in a source may have been made absolute by the parser with the baseURI, thus making it unable to find a system entry. In such a case, a systemSuffix entry is recommended over a system entry.

Specified by:: resolveResource in interface LSResourceResolver
Parameters:: type - the type of the resource being resolved, not used by the CatalogResolver; namespaceUri - the namespace of the resource being resolved, not used by the CatalogResolver; publicId - the public identifier of the external entity being referenced, or null if 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 referenced; baseUri - the absolute base URI, not used by the CatalogResolver
Returns:: a LSInput object if a mapping is found; null if no mapping is found and the javax.xml.catalog.resolve property is set to continue or ignore. Note that for LSResourceResolver, it is not possible to ignore a reference, ignore is therefore treated the same as continue.
Throws:: CatalogException - if no mapping is found and javax.xml.catalog.resolve is specified as strict