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() {     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

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.

Answer 2

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