Supple software

public class ParallelCounter {

    public int countWords1(List files) {
        ExecutorService executorService = Executors.newFixedThreadPool(4);
        List> counters = new ArrayList>();
        for(final File file : files) {
            counters.add(new Callable() {
                public Integer call() {
                    System.out.println("Starting file " + file.getName() + " at " + System.currentTimeMillis());
                    WordCounter counter = new WordCounter();
                    int count =  counter.count(file);
                    System.out.println("Done file " + file.getName() + " at " + System.currentTimeMillis());
                    return count;
                }
            });
        }
        try {
            List> results = executorService.invokeAll(counters);
            int totalCount = 0;
            for (Future future : results) {
                totalCount += future.get();
            }
            return totalCount;
        } catch (InterruptedException e) {
            throw new RuntimeException(e);
        } catch (ExecutionException e) {
            throw new RuntimeException(e);
        }
    }

    public static void main(String[] args) {
        long start = System.currentTimeMillis();
        ParallelCounter counter = new ParallelCounter();
        List files = new ArrayList(args.length);
        for (String filename : args) {
            files.add(new File(filename));
        }
        System.out.println("Total word count is " + counter.countWords1(files));
        System.out.println("Total elapsed time " +
(System.currentTimeMillis() - start));
    }
}