what is the difference

[ron87]

What is the difference between hashtable and hashmap

one i found is hashtable is thread safe and hashmap is not

any other differences?

[Nicholas Jordan]

Not really, I dug into this and found that a TreeMap will keep things sorted, for hashtable you get a lot of people telling you it is not in use anymore. They are worng ( wrong ) seems from what I read of hashmap it is not much different from hashtable except that you do not get as many people telling you it has been replaced.

Threading issues do not matter unless you are writing a program that creates threads.

[ron87]

But i think they both does not allow null keys
is it?

[arseny]

yes it is. And there is one more HashMap works faster that Hashtable in a single tread environment (someone told).

[mrbharatmehta]

Hashtable is the synchronized counterpart to HashMap. By this we mean that methods for Hashtable are synchronized.
Another difference is that while HashMap lets you have null values as well as one null key, a Hashtable doesn't let you have anything that's null.

[Tolls]

Not really, I dug into this and found that a TreeMap will keep things sorted, for hashtable you get a lot of people telling you it is not in use anymore. They are worng ( wrong ) seems from what I read of hashmap it is not much different from hashtable except that you do not get as many people telling you it has been replaced.

Threading issues do not matter unless you are writing a program that creates threads.

Well, most places I've seen where this (and Vector) come up are that, outside of an environment where they are shared between threads, the newer (non-thread safe versions) should be used.

Indeed, with the synchronised versions of the newer collections available (via the Collections class) it is arguable whether the older ones are required at all.