Package net.sf.saxon.s9api

Class XdmMap

  • All Implemented Interfaces:
    java.lang.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 Detail

      • 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​(java.util.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 Detail

      • 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 java.util.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.

      • asMap

        public java.util.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:
        java.lang.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:
        java.lang.ClassCastException - if the supplied key cannot be converted to an XdmAtomicValue
        java.lang.NullPointerException - if the supplied key is null

      • get

        public XdmValue get​(java.lang.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:
        java.lang.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:
        java.lang.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:
        java.lang.NullPointerException - if the supplied key is null

      • values

        public java.util.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 java.util.Set<java.util.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​(java.util.Map<K,​V> input)
                                  throws java.lang.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:
        java.lang.IllegalArgumentException - if any value in the input map cannot be converted to a corresponding XDM value.