Difference between Vector and ArrayList

[varavoorvishnu]

Hi All,
I found that in one of the site the difference between Vector and ArrayList.
The explanation given is
1."Vector,a Heavyweight and ArrayList is Lightweight".
and
2.Another one is Vector-Synchronized and ArrayList-unsynchronized.
I understood the second ,but I found difficult with the first answer.

My doubt is :
1.How do u define "Heavyweight " and "Lightweight" objects? What are they?
2.What does it have to do with Collections?

Regards,
Vishnu

 

[maxpower1]

1. Vector and ArrayList are lists implementation. Synchronized
means "thread safe" which adds a performance hit(heavy weight). On the other hand, ArrayList is not "thread safe". I use arrayList a lot more because I usually need it to display a bunch of read-only database records. If you need to do manipulations, and still want to make sure that it is thread-safe, then use Vectors.

what is a thread safety?

http://www.artima.com/designtechniques/threadsafety.html

~za~
You can't bring back a dead thread!

 

[maxpower1]

opp..

all these items fall under Collections

Collection
|
List
/ / Vector ArrayList



~za~
You can't bring back a dead thread!

 

[varavoorvishnu]

Hi Maxpower,
Thanx for the answers that u have given,
Now after reading ur points,I came to an understanding that
if thread is synchronized which inturn means more time consuming..so the time is the concern and hence u call it as heavy weight coz tht would reduce the performance.

Plz reply me bak stating if my understanding is right!!
Vishnu