How to execute tasks in ExecutorService sequentially?

Question

I have three threads that are joined, i.e. the second thread executes after the first dies.

This is the code I have:

public class Main {
    public s         


        

Answer 1

If what you want/need is to execute a group of jobs one after another but in a single thread different that the main app thread, then use Executors#newSingleThreadExecutor.

ExecutorService es = Executors.newSingleThreadExecutor();
es.submit(() -> System.out.println("Message 1"));
es.submit(() -> System.out.println("Message 2"));
es.submit(() -> System.out.println("Message 3"));
es.shutdown();