enum implementation inside interface - Java

It's perfectly legal to have an enum declared inside an interface. In your situation the interface is just used as a namespace for the enum and nothing more. The interface is used normally wherever you use it.

Example for the Above Things are listed below :

public interface Currency {  enum CurrencyType {    RUPEE,    DOLLAR,    POUND  }  public void setCurrencyType(Currency.CurrencyType currencyVal);}public class Test {  Currency.CurrencyType currencyTypeVal = null;  private void doStuff() {    setCurrencyType(Currency.CurrencyType.RUPEE);    System.out.println("displaying: " + getCurrencyType().toString());  }  public Currency.CurrencyType getCurrencyType() {    return currencyTypeVal;  }  public void setCurrencyType(Currency.CurrencyType currencyTypeValue) {    currencyTypeVal = currencyTypeValue;  }  public static void main(String[] args) {    Test test = new Test();    test.doStuff();  }}

In short, yes, this is okay.

The interface does not contain any method bodies; instead, it contains what you refer to as "empty bodies" and more commonly known as method signatures.

It does not matter that the enum is inside the interface.