Object Pooling in Java

Question

What are the pro\'s and con\'s of maintaining a pool of frequently used objects and grab one from the pool instead of creating a new one. Something like string interning exc

Answer 1

Unless the object is expensive to create, I wouldn't bother.

Benefits:

• Fewer objects created - if object creation is expensive, this can be significant. (The canonical example is probably database connections, where "creation" includes making a network connection to the server, providing authentication etc.)

Downsides:

• More complicated code
• Shared resource = locking; potential bottleneck
• Violates GC's expectations of object lifetimes (most objects will be shortlived)

Do you have an actual problem you're trying to solve, or is this speculative? I wouldn't think about doing something like this unless you've got benchmarks/profile runs showing that there's a problem.