Package net.sf.saxon.s9api

Class XdmMap

java.lang.Object
net.sf.saxon.s9api.XdmValue
net.sf.saxon.s9api.XdmItem
net.sf.saxon.s9api.XdmFunctionItem
net.sf.saxon.s9api.XdmMap
All Implemented Interfaces:
Iterable<XdmItem>
public class XdmMap extends XdmFunctionItem
A map in the XDM data model. A map is a list of zero or more entries, each of which is a pair comprising a key (which is an atomic value) and a value (which is an arbitrary value). The map itself is an XDM item.

An XdmMap is immutable.

As originally issued in Saxon 9.8, this class implemented the Map interface. It no longer does so, because it was found that the methods XdmItem.size(), put(XdmAtomicValue, XdmValue), and remove(net.sf.saxon.s9api.XdmAtomicValue) did not adhere to the semantic contract of that interface. Instead, it is now possible to obtain a view of this object as an immutable Java Map by calling the method asImmutableMap(). See bug 3824.

Since:
9.8

  • Constructor Details

    • XdmMap

      public XdmMap()
      Create an empty XdmMap

    • XdmMap

      public XdmMap(MapItem map)
      Create an XdmMap whose underlying value is a MapItem
      Parameters:
      map - the MapItem to be encapsulated

    • XdmMap

      public XdmMap(Map<? extends XdmAtomicValue,? extends XdmValue> map)
      Create an XdmMap supplying the entries in the form of a Java Map, where the keys and values in the Java Map are XDM values
      Parameters:
      map - a Java map whose entries are the (key, value) pairs
      Since:
      9.8

  • Method Details

    • getUnderlyingValue

      public MapItem getUnderlyingValue()
      Get the underlying implementation object representing the value. This method allows access to lower-level Saxon functionality, including classes and methods that offer no guarantee of stability across releases.
      Overrides:
      getUnderlyingValue in class XdmItem
      Returns:
      the underlying implementation object representing the value
      Since:
      9.8 (previously inherited from XdmValue which returns a Sequence)

    • mapSize

      public int mapSize()
      Get the number of entries in the map
      Returns:
      the number of entries in the map. (Note that the XdmItem.size() method returns 1 (one), because an XDM map is an item.)

    • put

      public XdmMap put(XdmAtomicValue key, XdmValue value)
      Create a new map containing an additional (key, value) pair. If there is an existing entry with the same key, it is removed
      Parameters:
      key - the key
      value - the value
      Returns:
      a new map containing the additional entry. The original map is unchanged.

    • remove

      public XdmMap remove(XdmAtomicValue key)
      Create a new map in which the entry for a given key has been removed. If there is no entry with the same key, the new map has the same content as the old (it may or may not be the same Java object)
      Parameters:
      key - the key
      Returns:
      a map without the specified entry. The original map is unchanged.

    • keySet

      public Set<XdmAtomicValue> keySet()
      Get the keys present in the map in the form of an unordered set.
      Returns:
      an unordered set of the keys present in this map, in arbitrary order.

    • asImmutableMap

      public Map<XdmAtomicValue,XdmValue> asImmutableMap()
      Return this map as an immutable instance of Map
      Returns:
      an immutable instance of Map backed by this map. Methods such as remove(net.sf.saxon.s9api.XdmAtomicValue) and put(net.sf.saxon.s9api.XdmAtomicValue, net.sf.saxon.s9api.XdmValue) applied to the result will always throw UnsupportedOperationException.

    • asMap

      public Map<XdmAtomicValue,XdmValue> asMap()
      Return a mutable Java Map containing the same entries as this map.
      Overrides:
      asMap in class XdmItem
      Returns:
      a mutable Map from atomic values to (sequence) values, containing a copy of the entries in this map. Changes to the returned map have no effect on the original XdmMap.
      Since:
      9.6.

    • clear

      public void clear()
      Removes all of the mappings from this map (optional operation). The map will be empty after this call returns.
      Throws:
      UnsupportedOperationException - if the clear operation is not supported by this map

    • isEmpty

      public boolean isEmpty()
      Returns true if this map contains no key-value mappings.
      Overrides:
      isEmpty in class XdmValue
      Returns:
      true if this map contains no key-value mappings

    • containsKey

      public boolean containsKey(XdmAtomicValue key)
      Returns true if this map contains a mapping for the specified key. More formally, returns true if and only if this map contains a mapping for a key k such that (key==null ? k==null : key.equals(k)). (There can be at most one such mapping.)
      Parameters:
      key - key whose presence in this map is to be tested
      Returns:
      true if this map contains a mapping for the specified key
      Since:
      9.8. Changed the method signature in 9.9.1.1 to match the implementation: see bug 3969.

    • get

      public XdmValue get(XdmAtomicValue key)
      Returns the value to which the specified key is mapped, or null if this map contains no mapping for the key.
      Parameters:
      key - the key whose associated value is to be returned.
      Returns:
      the value to which the specified key is mapped, or null if this map contains no mapping for the key
      Throws:
      ClassCastException - if the supplied key cannot be converted to an XdmAtomicValue
      NullPointerException - if the supplied key is null

    • get

      public XdmValue get(String key)
      Returns the value to which the specified string-valued key is mapped, or null if this map contains no mapping for the key. This is a convenience method to save the trouble of converting the String to an XdmAtomicValue.
      Parameters:
      key - the key whose associated value is to be returned. This is treated as an instance of xs:string (which will also match entries whose key is xs:untypedAtomic or xs:anyURI)
      Returns:
      the value to which the specified key is mapped, or null if this map contains no mapping for the key
      Throws:
      NullPointerException - if the supplied key is null

    • get

      public XdmValue get(long key)
      Returns the value to which the specified integer-valued key is mapped, or null if this map contains no mapping for the key. This is a convenience method to save the trouble of converting the integer to an XdmAtomicValue.
      Parameters:
      key - the key whose associated value is to be returned. This is treated as an instance of xs:integer (which will also match entries whose key belongs to another numeric type)
      Returns:
      the value to which the specified key is mapped, or null if this map contains no mapping for the key
      Throws:
      NullPointerException - if the supplied key is null

    • get

      public XdmValue get(double key)
      Returns the value to which the specified double-valued key is mapped, or null if this map contains no mapping for the key. This is a convenience method to save the trouble of converting the double to an XdmAtomicValue.
      Parameters:
      key - the key whose associated value is to be returned. This is treated as an instance of xs:double (which will also match entries whose key belongs to another numeric type)
      Returns:
      the value to which the specified key is mapped, or null if this map contains no mapping for the key
      Throws:
      NullPointerException - if the supplied key is null

    • values

      public Collection<XdmValue> values()
      Returns a Collection containing the values found in this map, that is, the value parts of the key-value pairs.
      Returns:
      a collection containing the values found in this map. The result may contain duplicates, and the ordering of the collection is unpredictable.

    • entrySet

      public Set<Map.Entry<XdmAtomicValue,XdmValue>> entrySet()
      Returns a Set of the key-value pairs contained in this map.
      Returns:
      a set of the mappings contained in this map

    • makeMap

      public static <K, V> XdmMap makeMap(Map<K,V> input) throws IllegalArgumentException
      Static factory method to construct an XDM map by converting each entry in a supplied Java map. The keys in the Java map must be convertible to XDM atomic values using the XdmAtomicValue.makeAtomicValue(Object) method. The associated values must be convertible to XDM sequences using the XdmValue.makeValue(Object) method.
      Type Parameters:
      K - the type of the keys
      V - the type of the values
      Parameters:
      input - the supplied map
      Returns:
      the resulting XdmMap
      Throws:
      IllegalArgumentException - if any value in the input map cannot be converted to a corresponding XDM value.