Package org.apache.commons.collections4.keyvalue

Class DefaultKeyValue<K,​V>

  • Type Parameters:
    K - the type of keys
    V - the type of values
    All Implemented Interfaces:
    KeyValue<K,​V>
    public class DefaultKeyValue<K,​V>
extends AbstractKeyValue<K,​V>
    A mutable KeyValue pair that does not implement Map.Entry.

    Note that a DefaultKeyValue instance may not contain itself as a key or value.

    Since:
    3.0

    • Constructor Summary

      Constructors 
      Constructor Description
      DefaultKeyValue()
      Constructs a new pair with a null key and null value.
      DefaultKeyValue​(java.util.Map.Entry<? extends K,​? extends V> entry)
      Constructs a new pair from the specified Map.Entry.
      DefaultKeyValue​(K key, V value)
      Constructs a new pair with the specified key and given value.
      DefaultKeyValue​(KeyValue<? extends K,​? extends V> pair)
      Constructs a new pair from the specified KeyValue.

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      boolean equals​(java.lang.Object obj)
      Compares this Map.Entry with another Map.Entry.
      int hashCode()
      Gets a hashCode compatible with the equals method.
      K setKey​(K key)
      Sets the key.
      V setValue​(V value)
      Sets the value.
      java.util.Map.Entry<K,​V> toMapEntry()
      Returns a new Map.Entry object with key and value from this pair.

      • Methods inherited from class java.lang.Object

        getClass, notify, notifyAll, wait, wait, wait

    • Constructor Detail

      • DefaultKeyValue

        public DefaultKeyValue()
        Constructs a new pair with a null key and null value.

      • DefaultKeyValue

        public DefaultKeyValue​(K key,
                       V value)
        Constructs a new pair with the specified key and given value.
        Parameters:
        key - the key for the entry, may be null
        value - the value for the entry, may be null

      • DefaultKeyValue

        public DefaultKeyValue​(KeyValue<? extends K,​? extends V> pair)
        Constructs a new pair from the specified KeyValue.
        Parameters:
        pair - the pair to copy, must not be null
        Throws:
        java.lang.NullPointerException - if the entry is null

      • DefaultKeyValue

        public DefaultKeyValue​(java.util.Map.Entry<? extends K,​? extends V> entry)
        Constructs a new pair from the specified Map.Entry.
        Parameters:
        entry - the entry to copy, must not be null
        Throws:
        java.lang.NullPointerException - if the entry is null

    • Method Detail

      • setKey

        public K setKey​(K key)
        Sets the key.
        Parameters:
        key - the new key
        Returns:
        the old key
        Throws:
        java.lang.IllegalArgumentException - if key is this object

      • setValue

        public V setValue​(V value)
        Sets the value.
        Parameters:
        value - the new value
        Returns:
        the old value of the value
        Throws:
        java.lang.IllegalArgumentException - if value is this object

      • toMapEntry

        public java.util.Map.Entry<K,​V> toMapEntry()
        Returns a new Map.Entry object with key and value from this pair.
        Returns:
        a MapEntry instance

      • equals

        public boolean equals​(java.lang.Object obj)
        Compares this Map.Entry with another Map.Entry.

        Returns true if the compared object is also a DefaultKeyValue, and its key and value are equal to this object's key and value.

        Overrides:
        equals in class java.lang.Object
        Parameters:
        obj - the object to compare to
        Returns:
        true if equal key and value

      • hashCode

        public int hashCode()
        Gets a hashCode compatible with the equals method.

        Implemented per API documentation of Map.Entry.hashCode(), however subclasses may override this.

        Overrides:
        hashCode in class java.lang.Object
        Returns:
        a suitable hash code