public class Task {
    public static enum TaskList {

        TASK_A {

            @Override
            void doProcess() {
                System.out.println("processing task A");

            }
        },
        TASK_B {
            @Override
            void doProcess() {
                System.out.println("processing task B");

            }
        },
        TASK_C {
            @Override
            void doProcess() {
                System.out.println("processing task C");
            }
        };

        abstract void doProcess();
    }
}

public static void main(String[] args) {
        Thread thread = new Thread(new Runnable() {

            @Override
            public void run() {
                //following code will be executed in multiple threads.

                Task.TaskList task = Task.TaskList.TASK_A;
                task.doProcess();

            }
        });
        thread.start();
    }