Developing Rules for Value Checks (1)

• the class containing the field,
• the name of the field,
• the lower and upper bounds,
• the error message text.

  class IntRangeCheck extends Check {
    int lower, upper;
    String error;
    IntRangeCheck( Class clazz, String field,
                   int lower, int upper,
                   String error ){
      super( clazz, field );
      ...
    }
  
    boolean isValid( Object object ){
      Object value = field.get( object );
      if( value == null ) return false;
      int intValue = (Integer)value;
      return lower <= intValue && intValue <= upper;
    }