Compares the specified object with this map for equality.
Returns true if the given object is also a map and the two Maps
represent the same mappings. More formally, two maps t1 and t2 represent
the same mappings if t1.entrySet().equals(t2.entrySet()).
This ensures that the equals method works properly across different
implementations of the Map interface.
Get a value for this key. Since this map is explicitly designed to
allow there to be more than one mapping per key, this method will return
an undetermined instance of the mapping. If no mapping exists, or the
selected value is null, null is returned.
Answer an iterator over all of the values for the given key. An iterator
is always supplied, even if the key is not present.
key - The key object
An iterator over all of the values for this key in the map
public int hashCode()
Returns the hash code value for this map. The hash code of a map is
defined to be the sum of the hashCodes of each entry in the map's
entrySet view. This ensures that t1.equals(t2) implies
that t1.hashCode()==t2.hashCode() for any two maps t1 and t2,
as required by the general contract of Object.hashCode
Associates the given value with the given key. Since this map formulation
allows many values for one key, previous associations with the key are not
lost. Consequently, the method always returns null (since the replaced value
is not defined).
Remove all of the associations for the given key. If only a specific
association is to be removed, use remove( java.lang.Object, java.lang.Object )
instead. Has no effect if the key is not present in the map. Since no
single specific association with the key is defined, this method always
Remove the specific association between the given key and value. Has
no effect if the association is not present in the map. If all values
for a particular key have been removed post removing this particular
association, the key will no longer appear as a key in the map.