Java – how to wait for all callables to complete execution before continuing?

I have the following hash code:

public class MyCallable implements Callable<Long> {
    @Override
    public Long call() throws Exception {
        // Do stuff...
    }
}

public class MyController {
    private ExecutorService executor = Executos.newCachedTreadPool();

    public Long concurrentDoStuff() {
        List<MyCallable> workers = makeWorkers();

        List<Long> allResults = new ArrayList<Long>();
        for(MyCallable worker : workers) {
            Future<Long> workerResults = executor.submit(worker);

            try {
                allResults.add(workerResults.get());
            } catch(InterruptedException ie) {
                // Handle...
            } catch(ExecutionException ee) {
                // Handle...
            }
        }

        // Question: how do I pause here and wait for all workers to finish?
    }
}

After the for loop, I want to wait for all workers to complete the task to continue What is the best / safest / most effective method? Thank you in advance!

Solution

You must use shutdown to close the executor and wait for all jobs to be processed using awaittermination