R1.java

  public class R1 implements IValidationRule {
     private Set<String> standingorderEtc;
   
      ...

     public boolean validate(Transaction context) throws Exception {
	Transaction current = context;
	if (standingorderEtc.contains(current.getType())) {
		return current.getAmount().compareTo(BigDecimal.valueOf(0)) < 0;
	} else {
		return true;
	}
     }
  }