局部类

局部类：方法内定义的类称为局部类

public static void main(String[] args) throws InterruptedException {
    new Thread(getTask()).start();
}
private static Runnable getTask(){
    class MyTask implements Runnable{

        @Override
        public void run() {
            System.err.println("这是局部内部类");
        }
    }
    return new MyTask();
}