Package org.apache.commons.collections.keyvalue

Class DefaultKeyValue

java.lang.Object
org.apache.commons.collections.keyvalue.AbstractKeyValue
org.apache.commons.collections.keyvalue.DefaultKeyValue
All Implemented Interfaces:
KeyValue
public class DefaultKeyValue extends AbstractKeyValue
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:
Commons Collections 3.0
Version:
$Revision: 646777 $ $Date: 2008-04-10 14:33:15 +0200 (Thu, 10 Apr 2008) $
Author:
James Strachan, Michael A. Smith, Neil O'Toole, Stephen Colebourne

  • Constructor Details

    • DefaultKeyValue

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

    • DefaultKeyValue

      public DefaultKeyValue(Object key, Object 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 pair)
      Constructs a new pair from the specified KeyValue.
      Parameters:
      pair - the pair to copy, must not be null
      Throws:
      NullPointerException - if the entry is null

    • DefaultKeyValue

      public DefaultKeyValue(Map.Entry entry)
      Constructs a new pair from the specified Map.Entry.
      Parameters:
      entry - the entry to copy, must not be null
      Throws:
      NullPointerException - if the entry is null

  • Method Details

    • setKey

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

    • setValue

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

    • toMapEntry

      public Map.Entry toMapEntry()
      Returns a new Map.Entry object with key and value from this pair.
      Returns:
      a MapEntry instance

    • equals

      public boolean equals(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 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 Object
      Returns:
      a suitable hash code