继承抽象类：

public abstract class Test1Abstract {

    private Integer a;

    static {

        System.out.println(123);
    }


    public void f1() {

    }

    public abstract void abstractf1();//抽象方法不能含有方法体


    public static void staticf1() {

    }

}

实现接口：

public interface ExecutorService extends Executor {