Прибавление 2-х чисел при помощи Аннотаций (Annotation)

import cf.tilgiz.annotation_test.handler.MathHandler;

import java.lang.reflect.Method;


public class Dispatcher {
    public static void main(String[] args) throws NoSuchMethodException {
        MathHandler mathHandler = new MathHandler();

        Class<MathHandler> cl = MathHandler.class;
        Method method = cl.getDeclaredMethod("addTwoNumbers", int.class, int.class);
        MathAnno mathAnno = method.getAnnotation(MathAnno.class);

        mathHandler.addTwoNumbers(mathAnno.num1(),mathAnno.num2());
    }
}

package cf.tilgiz.annotation_test.handler;

import cf.tilgiz.annotation_test.annotation.MathAnno;

public class MathHandler {
    @MathAnno(num1 = 10, num2 = 20)
    public void addTwoNumbers(int num1, int num2) {
        System.out.println(num1 + num2);
    }
}

package cf.tilgiz.annotation_test.annotation;

import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

@Target(ElementType.METHOD)
@Retention(RetentionPolicy.RUNTIME)
public @interface MathAnno {
    int num1() default 0;
    int num2() default 0;

}

Пул потоков Thread pool

import java.util.concurrent.ExecutorService;import java.util.concurrent.Executors;import java.util.concurrent.TimeUnit;
public class pool {
    public static void main(String[] args) {
        ExecutorService executorService = Executors.newFixedThreadPool(3);        for (int i = 0; i < 5; i++) {
            executorService.submit(new work(i));        }
        executorService.shutdown();        try {
            executorService.awaitTermination(1, TimeUnit.DAYS);        } catch (InterruptedException e) {
            e.printStackTrace();        }
    }
}
class work implements Runnable{
    private int id;    public work(int id) {
        this.id = id;    }
    @Override    public void run() {
        try {
            Thread.sleep(5000);        } catch (InterruptedException e) {
            e.printStackTrace();        }
        System.out.println("Work with id = " + id + " finished.");    }
}