Java 8: preferred way to count iterations of a lambda?

Question

I face the same problem often. I need to count the runs of a lambda for use outside the lambda.

E.g.:

myStream.stream().filter(...).forEa         


        

Answer 1

For me, this did the trick, hopefully someone finds it useful:

AtomicInteger runCount = new AtomicInteger(0);
myStream.stream().filter(...).forEach(item -> runCount.getAndIncrement());
System.out.println("The lambda ran " + runCount.get() + "times");

getAndIncrement() Java documentation states :

Atomically increments the current value, with memory effects as specified by VarHandle.getAndAdd. Equivalent to getAndAdd(1).