net.sf.saxon.query
Class StandardModuleURIResolver

java.lang.Object
  net.sf.saxon.query.StandardModuleURIResolver

All Implemented Interfaces:

Serializable, ModuleURIResolver

public class StandardModuleURIResolver
extends Object
implements ModuleURIResolver

This class is the standard ModuleURIResolver used to implement the "import module" declaration in a Query Prolog. It is used when no user-defined ModuleURIResolver has been specified, or when the user-defined ModuleURIResolver decides to delegate to the standard ModuleURIResolver.

Author:

Michael H. Kay

See Also:

Serialized Form

Constructor Summary

StandardModuleURIResolver()
Create a StandardModuleURIResolver.

Method Summary

static StandardModuleURIResolver	getInstance() Get the singular instance of this class
protected StreamSource	getQuerySource(URI absoluteURI) Get a StreamSource object representing the source of a query, given its URI.
StreamSource[]	resolve(String moduleURI, String baseURI, String[] locations) Resolve a module URI and associated location hints.

Methods inherited from class java.lang.Object

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

Constructor Detail

StandardModuleURIResolver

public StandardModuleURIResolver()

Create a StandardModuleURIResolver. Although the class is generally used as a singleton, a public constructor is provided so that the class can be named in configuration files and instantiated in the same way as user-written module URI resolvers.

Method Detail

getInstance

public static StandardModuleURIResolver getInstance()

Get the singular instance of this class

Returns:

the singular instance of this class

resolve

public StreamSource[] resolve(String moduleURI,
                              String baseURI,
                              String[] locations)
                       throws XPathException

Resolve a module URI and associated location hints.

Specified by:

resolve in interface ModuleURIResolver

Parameters:

moduleURI - The module namespace URI of the module to be imported; or null when loading a non-library module.

baseURI - The base URI of the module containing the "import module" declaration; null if no base URI is known

locations - The set of URIs specified in the "at" clause of "import module", which serve as location hints for the module

Returns:

an array of StreamSource objects each identifying the contents of a module to be imported. Each StreamSource must contain a non-null absolute System ID which will be used as the base URI of the imported module, and either an InputSource or a Reader representing the text of the module.

Throws:

XPathException - (error XQST0059) if the module cannot be located

getQuerySource

protected StreamSource getQuerySource(URI absoluteURI)
                               throws XPathException

Get a StreamSource object representing the source of a query, given its URI. This method attempts to discover the encoding by reading any HTTP headers. If the encoding can be determined, it returns a StreamSource containing a Reader that performs the required decoding. Otherwise, it returns a StreamSource containing an InputSource, leaving the caller to sort out encoding problems.

Parameters:

absoluteURI - the absolute URI of the source query

Returns:

a StreamSource containing a Reader or InputSource, as well as a systemID representing the base URI of the query.

Throws:

XPathException - if the URIs are invalid or cannot be resolved or dereferenced, or if any I/O error occurs