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I'm finding it difficult to put the exact question into words, so I'll just give an example.
I have two Enum types:
enum Shape { CAT, DOG; } enum Color { BLUE, RED; } I have a method:
public Object getInstance(String value, Class<?> type); I would like to use the method like:
// someValue is probably "RED", and someEnumClass is probably Color.class Color c = getInstance(someValue, someEnumClass); I've been having trouble determining exactly how to implement getInstance(). Once you know the exact Enum class that you want to instantiate, it's easy:
Color.valueOf("RED"); But how can this above line be accomplished with an unknown Class? (It is, however, known that the someEnumClass is a subclass of Enum.)
Thanks!
613
No, we cannot extend an enum in Java. Java enums can extend java. lang. Enum class implicitly, so enum types cannot extend another class.
Since C# doesn't support enum with string value, in this blog post, we'll look at alternatives and examples that you can use in code to make your life easier. The most popular string enum alternatives are: Use a public static readonly string. Custom Enumeration Class.
You cannot have an enum extend another enum , and you cannot "add" values to an existing enum through inheritance.
Use the Enum. IsDefined() method to check if a given string name or integer value is defined in a specified enumeration. Thus, the conversion of String to Enum can be implemented using the Enum. Parse ( ) and Enum.
public static <T extends Enum<T>> T getInstance(final String value, final Class<T> enumClass) { return Enum.valueOf(enumClass, value); } And the method is to be used as:
final Shape shape = getInstance("CAT", Shape.class); Then again, you can always use
final Shape shape = Shape.valueOf("CAT"); which is a shortcut for
Enum.valueOf(Shape.class, "CAT"); If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
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