What may be submitted to an ExecutorService?

Submit Runnable The Java ExecutorService submit(Runnable) method also takes a Runnable implementation, but returns a Future object. This Future object can be used to check if the Runnable has finished executing.

How do I get an ExecutorService result?

It seems that you want to wait for the completion of the task that you’ve submitted (why use an ExecutorService?) You can do that by submitting a Callable , the submit method will then return a Future . You can then get() to wait for completion and obtain the result.

What is ExecutorService multithreading?

The ExecutorService helps in maintaining a pool of threads and assigns them tasks. It also provides the facility to queue up tasks until there is a free thread available if the number of tasks is more than the threads available.

How do you implement ExecutorService?

A simple program of Java ExecutorService

  1. public class ExecutorServiceExample {
  2. public static void main(String[] args) {
  3. ExecutorService executorService = Executors.newFixedThreadPool(10);
  4. executorService.execute(new Runnable() {
  5. @Override.
  6. public void run() {
  7. System.out.println(“ExecutorService”);
  8. }

Does invokeAll block?

invokeAll() does indeed run the callable tasks in it’s own thread, but it also blocks waiting for the tasks to complete.

What is invokeAll?

1. ExecutorService invokeAll() API. invokeAll() method executes the given list of Callable tasks, returning a list of Future objects holding their status and results when all complete. It is overloaded method and is in two forms. Second method takes extra parameters denoting the timeout .

What does ExecutorService shutdown do?

Shutting down the ExecutorService shutdown() – when shutdown() method is called on an executor service, it stops accepting new tasks, waits for previously submitted tasks to execute, and then terminates the executor. shutdownNow() – this method interrupts the running task and shuts down the executor immediately.