Thread Example with CompletableFuture

ThreadTest.java

import java.util.ArrayList;
import java.util.Collection;
import java.util.concurrent.Callable;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.concurrent.atomic.AtomicInteger;

public class ThreadTest {


    public static void main(String[] args) {
        ExecutorService service = Executors.newFixedThreadPool(5);
        AtomicInteger foo = new AtomicInteger(0);
        Collection<CompletableFuture<String>> units = new ArrayList<>();
        for(int i = 0; i< 100; i++ ){
            units.add(CompletableFuture.supplyAsync(


                    () -> {
                        int val = foo.getAndIncrement();
                        if (val % 4 == 0) {
                            try {
                                Thread.sleep(5000);
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        } else {
                            try {
                                Thread.sleep(100);
                            } catch (InterruptedException e) {
                                e.printStackTrace();
                            }
                        }
                        return "Success for instance - " + val;
                    }, service));
        }

        CompletableFuture allOf = CompletableFuture.allOf(units.toArray(new CompletableFuture[units.size()]));

        //wait for 30 seconds

        try {
            allOf.get(10, TimeUnit.SECONDS);
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (ExecutionException e) {
            e.printStackTrace();
        } catch (TimeoutException e) {
            e.printStackTrace();
        }

        System.out.println("ALL DONE. LET's COUNT");
        for(CompletableFuture<String> unit : units){
            System.out.println("unit:"+unit);
            System.out.println("Done:"+unit.isDone());
            System.out.println("Is Cancelled:"+unit.isCancelled());
            System.out.println("Is Completed Exceptionally:"+unit.isCompletedExceptionally());
        }

    }
}