Spring roo, field enum

I'm new to Spring MVC and Spring Roo.

What is field enum?

How can I enumerate all allowed values?

Is it implemented using lookup table or check constraint?

Solution

Roo's field enum --fieldName --type command adds a private field of the specified enum type.

You can create the enum type by hand or use roo commands:

roo> enum type --class ~.domain.Colors
roo> enum constant --name BLAU
roo> enum constant --name VERMELL

This creates a Colors enum:

public Enum Colors {
  BLAU, VERMELL
}

Then you can use then enum type to define an entity field:

roo> entity --class ~.domain.Foo
roo> field enum --fieldName color --type ~.domain.Colors

This will define the Foo entity:

//Annotations and imports ommited for brevity
public class Foo{
     private Colors color;
}