Question

I want to know how to validate a list of nested objects in my form with Spring Validator (not annotation) in Spring MVC application.

class MyForm() {
    String myName;
    List<TypeA> listObjects;
}
class TypeA() {
    String number;
    String value;
}

How can I create a MyFormValidator to validate the listObjects and add error message for number and value of TypeA.

Answer 1

public class MyFormValidator implements Validator {

    @Override
    public boolean supports(Class clazz) {
        return MyForm.class.equals(clazz);
    }

    @Override
    public void validate(Object target, Errors errors) {
        MyForm myForm = (MyForm) target;

        for (int i = 0; i < myForm.getListObjects().size(); i++) {
            TypeA typeA = myForm.getListObjects().get(i);

            if(typeAHasAnErrorOnNumber) {
                errors.rejectValue("listObjects[" + i + "].number", "your_error_code");
            }

            ...
        }

        ...
    }

}

Interesting links :

• Spring MVC: Multiple Row Form Submit using List of Beans