AbstractMap.SimpleImmutableEntry

public static class AbstractMap.SimpleImmutableEntry extends Object
implements Entry<K, V> Serializable

An Entry maintaining an immutable key and value. This class does not support method setValue. This class may be convenient in methods that return thread-safe snapshots of key-value mappings.

Public Constructor Summary

SimpleImmutableEntry(K key, V value)
Creates an entry representing a mapping from the specified key to the specified value.
SimpleImmutableEntry(Entry<? extends K, ? extends V> entry)
Creates an entry representing the same mapping as the specified entry.

Public Method Summary

boolean
equals(Object o)
Compares the specified object with this entry for equality.
K
getKey()
Returns the key corresponding to this entry.
V
getValue()
Returns the value corresponding to this entry.
int
hashCode()
Returns the hash code value for this map entry.
V
setValue(V value)
Replaces the value corresponding to this entry with the specified value (optional operation).
String
toString()
Returns a String representation of this map entry.

Inherited Method Summary

Public Constructors

public SimpleImmutableEntry (K key, V value)

Creates an entry representing a mapping from the specified key to the specified value.

Parameters
key the key represented by this entry
value the value represented by this entry

public SimpleImmutableEntry (Entry<? extends K, ? extends V> entry)

Creates an entry representing the same mapping as the specified entry.

Parameters
entry the entry to copy

Public Methods

public boolean equals (Object o)

Compares the specified object with this entry for equality. Returns true if the given object is also a map entry and the two entries represent the same mapping. More formally, two entries e1 and e2 represent the same mapping if

   (e1.getKey()==null ?
    e2.getKey()==null :
    e1.getKey().equals(e2.getKey()))
   &&
   (e1.getValue()==null ?
    e2.getValue()==null :
    e1.getValue().equals(e2.getValue()))
This ensures that the equals method works properly across different implementations of the Map.Entry interface.

Parameters
o object to be compared for equality with this map entry
Returns
  • true if the specified object is equal to this map entry
See Also

public K getKey ()

Returns the key corresponding to this entry.

Returns
  • the key corresponding to this entry

public V getValue ()

Returns the value corresponding to this entry.

Returns
  • the value corresponding to this entry

public int hashCode ()

Returns the hash code value for this map entry. The hash code of a map entry e is defined to be:

   (e.getKey()==null   ? 0 : e.getKey().hashCode()) ^
   (e.getValue()==null ? 0 : e.getValue().hashCode())
This ensures that e1.equals(e2) implies that e1.hashCode()==e2.hashCode() for any two Entries e1 and e2, as required by the general contract of Object.hashCode().

Returns
  • the hash code value for this map entry
See Also

public V setValue (V value)

Replaces the value corresponding to this entry with the specified value (optional operation). This implementation simply throws UnsupportedOperationException, as this class implements an immutable map entry.

Parameters
value new value to be stored in this entry
Returns
  • (Does not return)

public String toString ()

Returns a String representation of this map entry. This implementation returns the string representation of this entry's key followed by the equals character ("=") followed by the string representation of this entry's value.

Returns
  • a String representation of this map entry