Package net.sf.saxon.s9api.streams

Class XdmCollectors

java.lang.Object
net.sf.saxon.s9api.streams.XdmCollectors
public class XdmCollectors extends 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()

  • Nested Class Summary

    Nested Classes
    Modifier and Type
    Class
    Description
    static class 
    XdmCollectors.MultipleItemException
    Unchecked exception that occurs when a collector method such as asAtomic() or asOptionalNode() is called, and the sequence contains more than one item.

  • Constructor Summary

    Constructors
    Constructor
    Description
    XdmCollectors()
     

  • Method Summary

    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<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<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<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<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<Optional<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<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 Details

    • XdmCollectors

      public XdmCollectors()

  • Method Details

    • 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:
      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:
      NoSuchElementException - if the stream is empty
      XdmCollectors.MultipleItemException - if the stream contains more than one node
      ClassCastException - if the stream contains an item that is not a node

    • asOptionalNode

      public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<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
      ClassCastException - if the stream contains an item that is not a node

    • asListOfNodes

      public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<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:
      ClassCastException - if the stream contains an item that is not a node

    • asListOfAtomic

      public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<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:
      ClassCastException - if the stream contains an item that is not an atomic value

    • asOptionalAtomic

      public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<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:
      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:
      NoSuchElementException - if the stream is empty
      XdmCollectors.MultipleItemException - if the stream contains more than one item
      ClassCastException - if the stream delivers an item that is not an atomic value

    • asOptionalString

      public static net.sf.saxon.s9api.streams.XdmCollectors.XdmCollector<Optional<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
      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<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
      NoSuchElementException - if the stream is empty
      UnsupportedOperationException - if the stream contains an item with no string value (such as a function item or an element with element-only content)