Thread-pool-demo is a project mainly written in Java, it's free.
A simple java demo project, which shows how java.util.concurrent ExecutorService (ThreadPool) can be used.
A java demo project how to use the java.util.concurrent ExecutorService (ThreadPool) see the class https://github.com/tux2323/thread-pool-demo/blob/master/src/main/java/com/github/tux2323/pooldemo/ProfilingService.java
For a simple load test for the profiling service see https://github.com/tux2323/thread-pool-demo/blob/master/src/test/java/com/github/tux2323/pooldemo/ProfilingServiceLoadTest.java