How to use invokeAll() to let all thread pool do their task?

Question

    ExecutorService pool=Executors.newFixedThreadPool(7);
        List> future=new ArrayList>();
        List<         


        

Answer 1

invokeAll is a blocking method. It means – JVM won’t proceed to next line until all the threads are completed. So I think there is something wrong with your thread future result.

System.out.println("name is:"+future.get(i).get().getName());

from this line I think there are some futures have no result and can be null, So you should check your code, if there are some Futures null,If so, get a if before this line executed.