Although jstack (Java Stack Trace) is a useful tool for learning more about a how a Java thread is behaving, VisualVM is an even easier method for obtaining the same type of information. It is ...

Also note that after a thread calls start(), subsequent calls to that method before the run() method exits cause start() to throw a java.lang.IllegalThreadStateException object.

Virtual threads, revealed in Java's Project Loom and generally available with the Java 21 LTS, promise unparalleled scalability, simplified asynchronous coding and more efficient resource utilization.