Enums shared static look-up method

Question

I have the following Enum:

public enum MyEnum{
    A(10, \"First\"), //
    B(20, \"Second\"), //
    C(35, \"Other options\");

    private Integer code;
           


        

Answer 1

This is a bit tricky because the values() method is static. You would actually need reflection, but there is a nice way to hide this using standard library functionality.

First, define an interface with the methods common to all of your enum types:

public interface Common {
    Integer getCode();
    String getDescription();
}

Then, make all your enums implement this interface:

public enum MyEnum implements Common {...}

The static method you want to have then looks like:

public static  & Common> T getValueOf( Class type, Integer code ) {
    final EnumSet values = EnumSet.allOf( type );
    for(T e : values) {
        if(e.getCode().equals( code )) {
            return e;
        }
    }
    throw new IllegalArgumentException( "No enum const " + type.getName() + " for code \'" + code + "\'" );
}