Enum type을 이용한 싱글톤 패턴

SingletonPatternEx3.java

package com.tistory.seungdols.effetive.ex_1;

/**
 * @PROJECT effectiveJava
 * @PACKAGE com.tistory.seungdols.effetive.ex_1
 * @WRITTER Administrator
 * @DATE 2015-09-21
 * @HISTORY
 * @DISCRIPT
 */

public enum Singleton{
    INSTANCE;
    public void execute(){}
}