Javaಠ_ಠAnnotation.java

package com.company;


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

@Retention(RetentionPolicy.RUNTIME)
@Target(ElementType.METHOD) //can use in method only.
@interface ಠ_ಠ {

    public String value() default "ಠ_ಠ";
}

ProcessAnnotation.java

package com.company;

import java.lang.annotation.Annotation;
import java.lang.reflect.InvocationTargetException;
import java.util.Arrays;

public class Process {

    public static void main(String[] args) {

        var obj = Main.class;

        for (var m : obj.getDeclaredMethods()) {

            processMethodsWithAnnotation(obj, m);
        }
    }

    private static void processMethodsWithAnnotation(Class<Main> obj, java.lang.reflect.Method m) {
        if(m.isAnnotationPresent(ಠ_ಠ.class)) {

            ಠ_ಠ hmm = m.getAnnotation(ಠ_ಠ.class);
            Object[] parameters = { null };

            try {
                m.invoke( obj.getDeclaredConstructor().newInstance(), parameters);
                System.out.println("( ͡° ͜ʖ ͡°)");
            } catch (IllegalAccessException | InstantiationException | InvocationTargetException | NoSuchMethodException e) {
                e.printStackTrace();
            }
        }
    }
}

Useಠ_ಠ.java

    @ಠ_ಠ
    public static void hmmm(String[] args) {
        System.out.println("hmmm");
    }