For ingame builds, you can use Spark or VisualVM (external program). Apart from that, there's not much more I can suggest. - Source: Reddit / about 2 months ago
My suggestion to further understand how the application works would be that you use a tool such as VisualVM while jmeter is running. There you can start the cpu sampler and look for the main thread. Then you can see which methods are called on that thread. - Source: Reddit / 21 days ago
JProfiler - JProfiler is the leading Java Profiler for profiling on the JVM. JProfiler's intuitive UI helps you resolve performance bottlenecks, pin down memory leaks and understand threading issues.
Eclipse Memory Analyzer - The Eclipse Foundation - home to a global community, the Eclipse IDE, Jakarta EE and over 350 open source projects, including runtimes, tools and frameworks.
Robot Console - Robot Console is a Message and Event Monitoring Software for IBM i thathas automatic message management, resource monitoring, and log monitoring.
Yourkit - Quickly get & share your browser details
Kcachegrind - Callgrind is a profiling tool and KCachegrind is able to visualize output of the profilers.
JConsole - Provides information about performance and resource consumption for Java applications.