java.util
Interface Map.Entry

Enclosing interface:

Map

public static interface Map.Entry

A map entry (key-value pair). The Map.entrySet() method returns a set view of these objects; there is no other valid way to come across them. These objects are only valid for the duration of an iteration; in other words, if you mess with one after modifying the map, you are asking for undefined behavior.

Since:

1.2

See Also:

Map, Map.entrySet()

Method Summary

boolean	equals(Object o) Compares the specified object with this entry.
Object	getKey() Get the key corresponding to this entry.
Object	getValue() Get the value corresponding to this entry.
int	hashCode() Returns the hash code of the entry.
Object	setValue(Object value) Replaces the value with the specified object (optional operation).

Method Detail

getKey

Object getKey()

Get the key corresponding to this entry.

Returns:

the key

getValue

Object getValue()

Get the value corresponding to this entry. If you already called Iterator.remove(), this is undefined.

Returns:

the value

setValue

Object setValue(Object value)

Replaces the value with the specified object (optional operation). This writes through to the map, and is undefined if you already called Iterator.remove().

Parameters:

value - the new value to store

Returns:

the old value

Throws:

UnsupportedOperationException - if the operation is not supported

ClassCastException - if the value is of the wrong type

IllegalArgumentException - if something about the value prevents it from existing in this map

NullPointerException - if the map forbids null values

hashCode

int hashCode()

Returns the hash code of the entry. This is defined as the exclusive-or of the hashcodes of the key and value (using 0 for null). In other words, this must be:

(getKey() == null ? 0 : getKey().hashCode())
^ (getValue() == null ? 0 : getValue().hashCode())

Overrides:

hashCode in class Object

Returns:

the hash code

See Also:

Object.equals(Object), System.identityHashCode(Object)

equals

boolean equals(Object o)

Compares the specified object with this entry. Returns true only if the object is a mapping of identical key and value. In other words, this must be:

(o instanceof Map.Entry)
&& (getKey() == null ? ((Map.Entry) o).getKey() == null
                     : getKey().equals(((Map.Entry) o).getKey()))
&& (getValue() == null ? ((Map.Entry) o).getValue() == null
                       : getValue().equals(((Map.Entry) o).getValue()))

Overrides:

equals in class Object

Parameters:

o - the object to compare

Returns:

true if it is equal

See Also:

Object.hashCode()