make threads have same name prefix

TaskThreadFactory.java

class TaskThreadFactory implements ThreadFactory {
        final ThreadGroup group;
        final AtomicInteger threadNumber = new AtomicInteger(1);
        final String namePrefix;

        TaskThreadFactory(String namePrefix) {
            SecurityManager s = System.getSecurityManager();
            group = (s != null) ? s.getThreadGroup() : Thread.currentThread().getThreadGroup();
            this.namePrefix = namePrefix;
        }

        public Thread newThread(Runnable r) {
            Thread t = new Thread(group, r, namePrefix + threadNumber.getAndIncrement());
            t.setDaemon(daemon);
            t.setPriority(getThreadPriority());
            return t;
        }
    }