Package net.sf.saxon.s9api.streams

Class XdmCollectors

  • public class XdmCollectors
extends java.lang.Object
    This class contains a number of static methods that deliver implementations of the Collector interface suitable for use with streams processing XDM nodes and other items.

    For example, the method asNode can be used in an expression such as XdmNode n = x.select(child("author")).collect(asNode()) to indicate that the content of the stream delivered by the select() call is to be delivered as a single XdmNode object, and that an exception should occur if the result is anything other than a single node.

    Although these methods can be used directly as arguments to Stream.collect(java.util.function.Supplier<R>, java.util.function.BiConsumer<R, ? super T>, java.util.function.BiConsumer<R, R>), it is usually more convenient to use them indirectly, the form of terminal operations on the class XdmStream, which extends Stream. So a more usual usage would be XdmNode n = x.select(child("author")).asNode()

    • Constructor Summary

      Constructors 
      Constructor Description
      XdmCollectors()  

    • Method Summary

      All Methods Static Methods Concrete Methods 
      Modifier and Type Method Description
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<XdmAtomicValue,​XdmAtomicValue> asAtomic()
      This method provides a Collector that returns the content of a stream as a single atomic value, that is, an instance of XdmAtomicValue.
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.List<XdmAtomicValue>,​XdmAtomicValue> asListOfAtomic()
      This method provides a Collector that returns the content of a stream as a list of atomic values (that is, as an instance of List<XdmAtomicValue>)
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.List<XdmNode>,​XdmNode> asListOfNodes()
      This method provides a Collector that returns the content of a stream as a list of XdmNode objects (that is, as an instance of List<XdmNode>)
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<XdmNode,​XdmNode> asNode()
      This method provides a Collector that returns the content of a stream as a single XdmNode.
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.Optional<XdmAtomicValue>,​XdmAtomicValue> asOptionalAtomic()
      This method provides a Collector that returns the content of a stream as an optional atomic value (that is, as an instance of Optional<XdmAtomicValue>)
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.Optional<XdmNode>,​XdmNode> asOptionalNode()
      This method provides a Collector that returns the content of a stream as an optional XdmNode (that is, as an instance of Optional<XdmNode>)
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.Optional<java.lang.String>,​XdmItem> asOptionalString()
      This method provides a Collector that returns the content of a stream as an optional String (that is, as an instance of Optional<String>) The stream must deliver either nothing, or a single XdmItem; the collector returns the string value of that item.
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.lang.String,​XdmItem> asString()
      This method provides a Collector that returns the content of a stream as an optional String (that is, as an instance of Optional<String>) The stream must deliver a single XdmItem; the collector returns the string value of that item.
      static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<XdmValue,​XdmItem> asXdmValue()
      This method provides a Collector that returns the content of a stream as an XdmValue

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • XdmCollectors

        public XdmCollectors()

    • Method Detail

      • asXdmValue

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<XdmValue,​XdmItem> asXdmValue()
        This method provides a Collector that returns the content of a stream as an XdmValue
        Returns:
        a collector that returns the single node delivered by the stream, or null if the stream is empty
        Throws:
        java.lang.ClassCastException - if the stream contains an item that is not a node

      • asNode

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<XdmNode,​XdmNode> asNode()
        This method provides a Collector that returns the content of a stream as a single XdmNode.
        Returns:
        a collector that returns the single node delivered by the stream
        Throws:
        java.util.NoSuchElementException - if the stream is empty
        XdmCollectors.MultipleItemException - if the stream contains more than one node
        java.lang.ClassCastException - if the stream contains an item that is not a node

      • asOptionalNode

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.Optional<XdmNode>,​XdmNode> asOptionalNode()
        This method provides a Collector that returns the content of a stream as an optional XdmNode (that is, as an instance of Optional<XdmNode>)
        Returns:
        a collector that returns the single node delivered by the stream, or Optional#empty() if the stream is empty
        Throws:
        XdmCollectors.MultipleItemException - if the stream contains more than one node
        java.lang.ClassCastException - if the stream contains an item that is not a node

      • asListOfNodes

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.List<XdmNode>,​XdmNode> asListOfNodes()
        This method provides a Collector that returns the content of a stream as a list of XdmNode objects (that is, as an instance of List<XdmNode>)
        Returns:
        a collector that returns the single node delivered by the stream, or null if the stream is empty
        Throws:
        java.lang.ClassCastException - if the stream contains an item that is not a node

      • asListOfAtomic

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.List<XdmAtomicValue>,​XdmAtomicValue> asListOfAtomic()
        This method provides a Collector that returns the content of a stream as a list of atomic values (that is, as an instance of List<XdmAtomicValue>)
        Returns:
        a collector that returns the list of atomic values delivered by the stream
        Throws:
        java.lang.ClassCastException - if the stream contains an item that is not an atomic value

      • asOptionalAtomic

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.Optional<XdmAtomicValue>,​XdmAtomicValue> asOptionalAtomic()
        This method provides a Collector that returns the content of a stream as an optional atomic value (that is, as an instance of Optional<XdmAtomicValue>)
        Returns:
        a collector that returns the single atomic value delivered by the stream, or Optional.empty() if the stream is empty
        Throws:
        java.lang.ClassCastException - if the stream contains an item that is not a node

      • asAtomic

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<XdmAtomicValue,​XdmAtomicValue> asAtomic()
        This method provides a Collector that returns the content of a stream as a single atomic value, that is, an instance of XdmAtomicValue. The stream must deliver a single atomic value.
        Returns:
        a collector that returns the string value of the single item delivered by the stream
        Throws:
        java.util.NoSuchElementException - if the stream is empty
        XdmCollectors.MultipleItemException - if the stream contains more than one item
        java.lang.ClassCastException - if the stream delivers an item that is not an atomic value

      • asOptionalString

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.util.Optional<java.lang.String>,​XdmItem> asOptionalString()
        This method provides a Collector that returns the content of a stream as an optional String (that is, as an instance of Optional<String>) The stream must deliver either nothing, or a single XdmItem; the collector returns the string value of that item.
        Returns:
        a collector that returns the string value of the single item delivered by the stream, if any
        Throws:
        XdmCollectors.MultipleItemException - if the stream contains more than one item
        java.lang.UnsupportedOperationException - if the stream contains an item with no string value (such as a function item or an element with element-only content)

      • asString

        public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<java.lang.String,​XdmItem> asString()
        This method provides a Collector that returns the content of a stream as an optional String (that is, as an instance of Optional<String>) The stream must deliver a single XdmItem; the collector returns the string value of that item.
        Returns:
        a collector that returns the string value of the single item delivered by the stream, if any
        Throws:
        XdmCollectors.MultipleItemException - if the stream contains more than one item
        java.util.NoSuchElementException - if the stream is empty
        java.lang.UnsupportedOperationException - if the stream contains an item with no string value (such as a function item or an element with element-only content)