Question

Object creation is a bottleneck in my application.

I think that adding more threads for object creation makes the situation worse, because object creation is a CPU-bound task, right?

Then, how to improve performance?

Answer 1

Often the problem is not object creation itself, but repeated object creation and garbage generation. That causes two performance hits: creating all those objects and extra garbage collection stalls.

First, you should use profiling tools to verify that excessive object creation is the source of your performance problems. Assuming that you have verified that this is the problem, there are various things to look for and strategies to try. It all depends on how your code is written, so there’s no one recommendation that will work. This list of Java performance guidelines from IBM is definitely worth applying. It identifies how to avoid many of the most common sins: don’t create objects inside loops; use StringBuilder instead of a series of string concatenation expressions; use primitive types and avoid auto-boxing/unboxing where possible; cache frequently used objects; allocate collection classes with an explicit capacity instead of allowing them to grow; etc.

Another nice resource is Chapter 4 of the book Java Performance Tuning. (You can read it on-line here.)

If you search the web for excessive object creation java, you can find lots of other recommendations.