使用构造函数本身中的ExecutorService.submit（）创建单例类的线程？

Question

我有一个本质上是Singelton的类，并实现了Callable接口。可以预期的是，一旦实例化，我应该立即启动该单例类的线程。尝试在构造函数，静态块，构造函数块中执行此操作，但是我得到了ExceptionInInitializerError，因为我认为该对象直到那个时候才被实例化。谁能指导我该怎么做？

  

类结构在下面

interface X implements Callable<Object>{
    void metho1();
}

class A implements X{

    private Map<String, String> map = new HashMap<>();

    private ExecutorService executor = Executors.newFixedThreadPool(1);

    private static A a = new A();

    public static A getA(){
        return a;
    }

    private A()
    {
        //Obiously will not work because by the time I reach here 'a' is not instantiataed
        executor.submit(getA());
    }

    static{
        //This also does not work
        executor.submit(getA());
    }

    @Override
    public Object call()
    {
         //Do something
    }

    @Override
    public void metho1(){
         //Do something
    }

}