Returning values from a call method to future object

Question

How can i return the iterated set values which are of type string from a call method to a future object.do i need to store the iterated vales in a array and return that array or can any one help me out

Answer 1

Use a Callable<List<String>>, submit it to an executor, which will return a Future whose get() method will return a List<String>.

ExecutorService executorService = Executors.newSingleThreadExecutor();
Callable<List<String>> task = new Callable<List<String>>() {
    public List<String> call() throws Exception {
        List<String> list = new ArrayList<String>();
        // populate list
        return list;
    }
};
Future<List<String>> future = executorService.submit(task);

// the list from above, returns once execution is complete
List<String> list = future.get(); 

Answer 2

Use submit() method of ExecutorService which returns Future Object.