Question

I have some code that acquires a value for an enum:

StringUtils.isEmpty(getEnumMember().value());

The supporting code looks like this:

public CustomEnum getEnumMember() {
    return enumMember;
}

----

public enum CustomEnum {

    TEXT1("text1"),
    TEXT2("text2"),
    TEXT3("text3");

    private final String value;

    CustomEnum(String v) {
        value = v;
    }

    public String value() {
        return value;
   }

   ...
}

I am wondering if there is a way for getEnumMember to handle null enums in the same way I can handle null objects. For example:

public CustomEnum getEnumMember() {
    if (enumMember ==null) {
        return new CustomEnum();
    }
    return enumMember;
}

But I cannot instantiate a “new CustomEnum”. How would you handle this so that getEnumMember() would not return a null? I would prefer not to create a special enum value for “ENUM_IS_NULL(“”)”.

Answer 1

When you create an enum, you’re saying that any variable of that type will have one of a defined list of values – or be null. That’s inescapable. So you must either accept the null, or determine an appropriate value – whether it is one of your existing enum values or a new one you add. These are your only options. The code return new CustomEnum(); just doesn’t make sense; you must be selecting one of the enumerated values, and you have to specify which one.