How to make a function take a specific group of constants

Question

I know i asked this before, maybe a year ago, but I totally forgot how to do it, and I haven't been programming much lately. But I was wondering if somebody can tell me how to make a certain function take specific constants. For example there are java functions, of which I can not remember that will only take certain values. So the function might look like:
public getInfo(String INFONAME){}Where INFONAME has to be like one of two names or something, and they are constants that are defined somewhere else. If anybody knows what I mean by this, and knows how to create functions like that please let me know. Thank you.

Answer 1

here's an overkill,
import java.util.*;
abstract class DoWhatever {
    public static Hashtable ht = null;
    public static Object DoWhat( String s, Object obj ) {
     if( null == ht ) {
         ht = new Hashtable();
         ht.put( ThisDoWhatever.NAME, new ThisDoWhatever() );
         ht.put( ThatDoWhatever.NAME, new ThatDoWhatever() );        
     return ( (DoWhatever) ht.get( s ) ).doWhatever( obj );
    public abstract Object doWhatever( Object obj );
class ThisDoWhatever extends DoWhatever {
    public final static String NAME = "this";
    public Object doWhatever( Object obj ) {
     System.out.println( NAME );
     return null;
class ThatDoWhatever extends DoWhatever {
    public final static String NAME = "that";
    public Object doWhatever( Object obj ) {
     System.out.println( NAME );
     return null;
public class DoThisOrThat {
    public static void main( String[] args ) {
     DoWhatever.DoWhat( args[ 0 ], null );
}