Using the if-then-else framework, Part 3

class URLProcessor_good extends URLProcessor implements logic.Updateable {
    static final String URL_STR = "urlString";
    URLProcessor_good(){
        super();
    }
    void decideUrl() {
        try {
            Invoker inv = new ConcreteInvoker((Updateable)this);
            inv.execute();
        }
        catch(NestingTooDeepException ntde) {}
        catch(IllegalExpressionException iee) {}
        catch(RuleNotFoundException rnfe) {}
        catch(DataNotFoundException dnfe) {}
    }
/** Updateable interface implementation */
    public void doUpdate(Hashtable ht) {
       if(ht == null) return;
       Object ob = ht.get(Action.MAIN_KEY);
       if(ob != null && ob instanceof String) {
           setUrl((String)ob);
       }
    }
    static class OtherCondition extends Condition {
        public static final String KEY = "key";
        public OtherCondition(Hashtable ht) {
            super(ht);
        }
        public Boolean evaluate() throws DataNotFoundException {
            Object ob = null;
            if(getData() == null || (ob = getData().get(KEY)) == null) {
                throw new DataNotFoundException();
            }
            if(!(ob instanceof DataBank.Region)) {
                return Boolean.FALSE;
            }
            DataBank.Region region = (DataBank.Region)ob;
            boolean result = !region.equals(DataBank.WEST_REGION) &&
                             !region.equals(DataBank.EAST_REGION);
            return new Boolean(result);
        }
    }
    static class MemberCondition extends Condition {
        public static final String KEY = "id";
        public static final String TABLE = "table";
        public MemberCondition(Hashtable ht) {
            super(ht);
        }
        public Boolean evaluate() throws DataNotFoundException {
            Object id = null, table = null;
            if(getData() == null || 
               ((id = getData().get(KEY)) == null) || 
                ((table = getData().get(TABLE))==null) ||
                 !(table instanceof Hashtable)) {
                throw new DataNotFoundException();
            }                                
            Hashtable members = (Hashtable)table;
            return new Boolean(members.containsKey(id));
        }
    }
    public class ConcreteInvoker extends Invoker {
        public ConcreteInvoker(Updateable ud) throws NestingTooDeepException {
            super(ud);
        }
        public void loadRules() throws NestingTooDeepException {
            rules = new Rules();
            try {
                //             Conditions:                              Actions:
                //        East|West|Other|Lim|Member    
                rules.addRule("TFFT*",               new Action(ud,EAST_PRIVILEGED));
                rules.addRule("TFFF*",                    new Action(ud,EAST_NOT_PRIVILEGED));
                rules.addRule("FTFTT",               new Action(ud,WEST_MEMBER_PRIVILEGED));
                rules.addRule("FTFTF",               new Action(ud,WEST_NONMEMBER_PRIVILEGED)); 
                rules.addRule("FTFFT",               new Action(ud,WEST_MEMBER_NOT_PRIVILEGED));
                rules.addRule("FTFFF",               new Action(ud,WEST_NONMEMBER_NOT_PRIVILEGED)); 
                rules.addRule("FFT**",               new Action(ud,OTHER_REGION));
             }
             catch(NestingTooDeepException e) {
                 throw e;
             }
        }
                
        public void loadConditions() throws IllegalExpressionException {
            try {  
                conditions = new Vector(5);
                conditions.addElement(new Condition(db.getRegion(),DataBank.EAST_REGION));
                conditions.addElement(new Condition(db.getRegion(),DataBank.WEST_REGION));
                Hashtable other = new Hashtable();
                other.put(OtherCondition.KEY,db.getRegion());
                conditions.addElement(new OtherCondition(other));
                conditions.addElement(new Condition(db.LIMIT_THRESHOLD, Condition.LESS,db.getLimit() ));                         
                Hashtable mem = new Hashtable();
                mem.put(MemberCondition.TABLE, db.getWestMembers());
                mem.put(MemberCondition.KEY, db.getUserId());
                conditions.addElement(new MemberCondition(mem));
            }
            catch(IllegalExpressionException e) {
                throw e;
            }
        }
    }
}