Validate a list of nested objects with Spring validator?

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() {
    St         


        

Answer 1

For the nested validation, you can do as below:

public class MyFormValidator implements Validator {

    private TypeAValidator typeAValidator;

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

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

        int idx = 0;
        for (TypeA item : myForm.getListObjects()) {

            errors.pushNestedPath("listObjects[" + idx + "]");
            ValidationUtils.invokeValidator(this.typeAValidator, item, errors);
            errors.popNestedPath();
            idx++;

            ...
        }

        ...
    }
}

public class TypeAValidator implements Validator{

    @Override
    public boolean supports(Class clazz) {
        return TypeA.class.isAssignableFrom(clazz);
    }

    @Override
    public void validate(Object target, Errors errors) {
        TypeA objTypeA = (TypeA)target;

        ValidationUtils.rejectIfEmpty(errors, "number", "number.notEmpty");
    }
}

Hope this helps.