java.lang.Object
java.util.AbstractMap.SimpleEntry<K,V>
- All Implemented Interfaces:
Serializable
,Map.Entry<K,
V>
- Enclosing class:
- AbstractMap<K,
V>
public static class AbstractMap.SimpleEntry<K,V>
extends Object
implements Map.Entry<K,V>, Serializable
An Entry maintaining a key and a value. The value may be
changed using the
setValue
method. Instances of
this class are not associated with any map's entry-set view.- API Note:
- This class facilitates the process of building custom map
implementations. For example, it may be convenient to return
arrays of
SimpleEntry
instances in methodMap.entrySet().toArray
. - Since:
- 1.6
- See Also:
-
Constructor Summary
ConstructorDescriptionSimpleEntry
(Map.Entry<? extends K, ? extends V> entry) Creates an entry representing the same mapping as the specified entry.SimpleEntry
(K key, V value) Creates an entry representing a mapping from the specified key to the specified value. -
Method Summary
Modifier and TypeMethodDescriptionboolean
Compares the specified object with this entry for equality.getKey()
Returns the key corresponding to this entry.getValue()
Returns the value corresponding to this entry.int
hashCode()
Returns the hash code value for this map entry.Replaces the value corresponding to this entry with the specified value.toString()
Returns a String representation of this map entry.
-
Constructor Details
-
SimpleEntry
Creates an entry representing a mapping from the specified key to the specified value.- Parameters:
key
- the key represented by this entryvalue
- the value represented by this entry
-
SimpleEntry
Creates an entry representing the same mapping as the specified entry.- Parameters:
entry
- the entry to copy
-
-
Method Details
-
getKey
Returns the key corresponding to this entry. -
getValue
Returns the value corresponding to this entry. -
setValue
Replaces the value corresponding to this entry with the specified value. -
equals
Compares the specified object with this entry for equality. Returnstrue
if the given object is also a map entry and the two entries represent the same mapping. More formally, two entriese1
ande2
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 theequals
method works properly across different implementations of theMap.Entry
interface. -
hashCode
public int hashCode()Returns the hash code value for this map entry. The hash code of a map entrye
is defined to be:(e.getKey()==null ? 0 : e.getKey().hashCode()) ^ (e.getValue()==null ? 0 : e.getValue().hashCode())
This ensures thate1.equals(e2)
implies thate1.hashCode()==e2.hashCode()
for any two Entriese1
ande2
, as required by the general contract ofObject.hashCode()
. -
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.
-