Seeding form fields using FormService

Is there any way to fill a form using FormService or any other Java API solution?

for (Task task : tasks) {
List formFields = formService.getTaskFormData(task.getId()).getFormFields();
for (FormField formField : formFields) {"Input label: " + formField.getLabel());

I’d like to fill and send a form using only Java API.

Map<String, Object> params = new HashMap<String, Object>();
params.put(“first_name”, “John”);
formService.submitTaskForm(task.getId(), params);