Conveniently map between enum and int / String

Question

When working with variables/parameters that can only take a finite number of values, I try to always use Java\'s enum, as in

public enum BonusT         


        

Answer 1

Just because the accepted answer is not self contained:

Support code:

public interface EnumWithCode & EnumWithCode> {

    public Integer getCode();

    E fromCode(Integer code);
}


public class EnumWithCodeMap & EnumWithCode> {

    private final HashMap _map = new HashMap();

    public EnumWithCodeMap(Class valueType) {
        for( V v : valueType.getEnumConstants() )
            _map.put(v.getCode(), v);
    }

    public V get(Integer num) {
        return _map.get(num);
    }
}

Example of use:

public enum State implements EnumWithCode {
    NOT_STARTED(0), STARTED(1), ENDED(2);

    private static final EnumWithCodeMap map = new EnumWithCodeMap(
            State.class);

    private final int code;

    private State(int code) {
        this.code = code;
    }

    @Override
    public Integer getCode() {
        return code;
    }

    @Override
    public State fromCode(Integer code) {
        return map.get(code);
    }

}