What are the differences between a HashMap and a Hashtable in Java? Which is more efficient for non-threaded applications?
There are several differences between HashMap and Hashtable in Java: Hashtable is synchronized, whereas HashMap is not. This makes HashMap better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones. Hashtable does not allow null keys or values. HaRead more
There are several differences between HashMap
and Hashtable
in Java:
Hashtable
is synchronized, whereasHashMap
is not. This makesHashMap
better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones.Hashtable
does not allownull
keys or values.HashMap
allows onenull
key and any number ofnull
values.- One of HashMap’s subclasses is
LinkedHashMap
, so in the event that you’d want predictable iteration order (which is insertion order by default), you could easily swap out theHashMap
for aLinkedHashMap
. This wouldn’t be as easy if you were usingHashtable
.
Since synchronization is not an issue for you, I’d recommend HashMap
. If synchronization becomes an issue, you may also look at ConcurrentHashMap
.
There are several differences between HashMap and Hashtable in Java: Hashtable is synchronized, whereas HashMap is not. This makes HashMap better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones. Hashtable does not allow null keys or values. HaRead more
There are several differences between
HashMap
andHashtable
in Java:Hashtable
is synchronized, whereasHashMap
is not. This makesHashMap
better for non-threaded applications, as unsynchronized Objects typically perform better than synchronized ones.Hashtable
does not allownull
keys or values.HashMap
allows onenull
key and any number ofnull
values.LinkedHashMap
, so in the event that you’d want predictable iteration order (which is insertion order by default), you could easily swap out theHashMap
for aLinkedHashMap
. This wouldn’t be as easy if you were usingHashtable
.Since synchronization is not an issue for you, I’d recommend
See lessHashMap
. If synchronization becomes an issue, you may also look atConcurrentHashMap
.