Interface Destination

  • All Known Implementing Classes:
    AbstractDestination, DOMDestination, NullDestination, RawDestination, ReceivingDestination, SAXDestination, SchemaValidator, SchemaValidatorImpl, Serializer, TeeDestination, XdmDestination, XMLStreamWriterDestination, XQueryEvaluator, XsltTransformer

    public interface Destination
    A Destination represents a place where XDM values can be sent. It is used, for example, to define the output of a transformation or query.

    A Destination is either a tree destination or a raw destination. A tree destination performs sequence normalization on the stream of events passed to it, to construct a tree rooted at a single XDM document node, as defined in the W3C serialization specification (even if the destination is not actually a serializer). A raw destination omits this step. Examples of tree destinations are those designed to accept XML: DOMDestination, SAXDestination, XdmDestination, SchemaValidator.

    The Serializer acts as a tree destination when the output methods XML, HTML, XHTML, or TEXT are used, but as a raw destination when the output method is JSON or ADAPTIVE.

    The interface Destination has some similarities with the JAXP Result class. It differs, however, in that implementations of this interface can be written by users or third parties to define new kinds of destination, and any such implementation can be supplied to the Saxon methods that take a Destination as an argument.

    Implementing a new Destination will generally require access to implementation-level classes and methods within the Saxon product. The only method that needs to be supplied is getReceiver(net.sf.saxon.event.PipelineConfiguration, net.sf.saxon.serialize.SerializationProperties), which returns an instance of Outputter, and unless you use an existing implementation of Receiver, you will need to handle internal Saxon concepts such as name codes and name pools.

    In general a Destination is not thread-safe (cannot be used from more than one thread), and is not serially reusable. So a Destination should only be used once. A Destination supplied to Saxon may be modified by Saxon.

    The close() method is called by the system when it finishes writing the document, and this should cause all resources held by the Destination to be released.

    • Method Detail

      • setDestinationBaseURI

        void setDestinationBaseURI​( baseURI)
        Set the base URI of the resource being written to this destination
        baseURI - the base URI to be used
      • getDestinationBaseURI getDestinationBaseURI()
        Get the base URI of the resource being written to this destination
        the baseURI, or null if none is known
      • getReceiver

        Receiver getReceiver​(PipelineConfiguration pipe,
                             SerializationProperties params)
                      throws SaxonApiException
        Return a Receiver. Saxon calls this method to obtain a Receiver, to which it then sends a sequence of events representing an XDM value. The method is intended primarily for internal use, and may give poor diagnostics if used incorrectly.

        This method is normally only called once. However, in the case where a stylesheet includes a call of xsl:result-document with no href attribute (or with an href attribute that resolves to the base output URI of the transformation), the method may be called a second time (with a potentially different set of serialization parameters, and perhaps a different validation request) to return a second Outputter, which will typically write to the same destination. The XSLT rules ensure that it is not possible to write principal and secondary output to the same destination, so only one of these Receivers will actually be used.

        pipe - The pipeline configuration. This is supplied so that the destination can use information from the configuration (for example, a reference to the name pool) to construct or configure the returned Receiver.
        params - Serialization parameters known to the caller of the method; typically, output properties defined in a stylesheet or query. These will mainly be of interest if the destination is performing serialization, but some properties (such as item-separator) are also used in other situations. These properties are typically subordinate to any properties defined on the (serializer) destination itself: for example if indent=yes was explicitly specified on a Serializer, this takes precedence over indent=no defined in a query or stylesheet.

        The SerializationProperties object may also contain a factory object for generating a validator to add to the output pipeline. The Destination object is responsible for instantiating this validator and inserting it into the pipeline. In most cases this is done by invoking the helper method SerializationProperties.makeSequenceNormalizer(Receiver). Validation can be skipped in the case of non-XML destinations.

        the Receiver to which events are to be sent.

        It is the caller's responsibility to initialize this Receiver with a PipelineConfiguration before calling its open() method.

        The Receiver is expected to handle a regular event sequence as defined in RegularSequenceChecker. It is the caller's responsibility to ensure that the sequence of calls to the Receiver satisfies these rules, and it is the responsibility of the implementation to accept any sequence conforming these rules; the implementation is not expected to check that the sequence is valid, but it can do so if it wishes by inserting a RegularSequenceChecker into the pipeline.

        The sequence of events passed to the Receiver represents the raw results of the query or transformation. If the Destination is to perform sequence normalization, this is typically done by returning a SequenceNormalizer as the result of this method.

        The returned Receiver is responsible for ensuring that when its Outputter.close() method is called, this results in all registered onClose actions being invoked. An implementation returning a SequenceNormalizer can achieve this by registering the actions with the SequenceNormalizer.onClose(java.util.List<net.sf.saxon.s9api.Action>) method.

        Only a single call on this method will be made during the lifetime of the Destination object, with the exception of the case noted above where a secondary result document is written to the same destination as the principal transformation result.

        SaxonApiException - if the Receiver cannot be created
      • onClose

        void onClose​(Action listener)
        Register a listener to be notified when a Outputter linked to this destination is closed.

        Example: destination.onClose(() -> System.out.println("Finished writing to " + uri)

        The method must be called before the call on getReceiver(PipelineConfiguration, SerializationProperties); the effect of calling it after getting a Receiver, but before closing the Outputter, is undefined.

        listener - an object to be notified when writing to the destination is successfully completed
      • closeAndNotify

        void closeAndNotify()
                     throws SaxonApiException
        Close the destination and notify all registered listeners that it has been closed. This method is intended for internal use by Saxon. The method first calls close() to close the destination, then it calls Consumer.accept(T) on each of the listeners in turn to notify the fact that it has been closed.
        SaxonApiException - if the close() method throws SaxonApiException.
      • close

        void close()
            throws SaxonApiException
        Close the destination, allowing resources to be released. Saxon calls this method when it has finished writing to the destination.

        The close() method should not cause any adverse effects if it is called more than once. If any other method is called after the close() call, the results are undefined. This means that a Destination is not, in general, serially reusable.

        If an onClose(net.sf.saxon.s9api.Action) action has been associated with the destination, this will be called after the destination is closed.

        SaxonApiException - if any failure occurs