Difference: WritingTasks (46 vs. 47)

.public class CombinedTask extends Task {
        private static final String TASKNAME = "combined";
        private static final String PRIME = "input";
        /** Jython doc string */
        public static PyString __doc__;

        /**Constructor*/
        public CombinedTask() {
            super(TASKNAME);
            addTaskParameter(TaskUtil.buildParameter(PRIME, Object.class, INPUT, MANDATORY, null, NULL_NOT_ALLOWED,
                    "String, Integer or Product"));

            getParameter(PRIME).setParameterValidator(new ParameterValidatorAdapter() {
                @Override
                public void validate(Object value) throws ParameterValidationException {
                    if (value instanceof String || value instanceof Integer || value instanceof Product) {
                        return;
                    }
                    throw new ParameterValidationException("Not String, Integer or Product but " + value.getClass());
                }
            });
            setDescription("task to test object parameters");
            __doc__ = TaskUtil.makeDoc(this);
        }


        @Override
        public void execute() {
            Object prime = getValue(PRIME);
            if (prime instanceof String) {
                System.out.println("A String " + prime);
            } else if (prime instanceof Integer) {
                System.out.println("An Integer " + prime);
            } else {
                System.out.println("A Product " + prime);
            }
        }
}

• Use multiple optional parameters (not recommended, too many parameters)