Java: Singleton using ENUM.. Is my object singleton and threadsafe

Question

I'm trying to understand creating a Singleton Object using Enum. I wrote this code. Is this threadsafe?. Please tell me if not ,how to make this

 public enum MySingleton {

    INSTANCE;
    private static final Employee emp = Employee.getInstance();
    }


public class Employee {
    private static Employee emp;

    public static Employee getInstance(){
    emp=new Employee();
    return emp;
    }
}

have you read this http://stackoverflow.com/questions/70689/what-is-an-efficient-way-to-implement-a-singleton-pattern-in-java? — Nicolas Filotto, Jun 10 '16 at 12:12
@NicolasFilotto,yes I did.still have confusion regarding how to make `Employee` singleton using Enum — Anil Kumar, Jun 10 '16 at 12:13
you want to implement the singleton pattern for Employee or MySingleton? — Nicolas Filotto, Jun 10 '16 at 12:17
so the code that you are looking for is public enum Employee { INSTANCE } — Nicolas Filotto, Jun 10 '16 at 12:19
@NicolasFilotto, It means I'm not taking `Employee` as a class , but as ENUM — Anil Kumar, Jun 10 '16 at 12:21
yes that's right you don't need a class and an enum only an enum — Nicolas Filotto, Jun 10 '16 at 12:22

Peter Lawrey · Answer 1 · 2016-06-10T12:19:06.230

0

It's not thread safe because Employee.getInstance() could be called by multiple threads and return one or more objects.

A simple solution is to make Employee an interface

public enum MySingleton implements Employee {
    INSTANCE;
}

public interface Employee {

}

This is thread safe as the construction of INSTANCE is thread safe.

edited Jun 10 '16 at 12:19

answered Jun 10 '16 at 12:16

Peter Lawrey

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Now How will i get `Employee` object – Anil Kumar Jun 10 '16 at 12:20
1

@AnilKumar with MySingleton.INSTANCE in this case – Nicolas Filotto Jun 10 '16 at 12:21

Java: Singleton using ENUM.. Is my object singleton and threadsafe

1 Answers1