Thymeleaf Spring Validation doesn't display - spring-boot

Question

I am trying display error message on HTML which i got from Controller, but i dont see the message displaying.
I printed the ${#fields.hasErrors('name')} and i see it give me false
I debugged my code, and I found there is an error
com.gurnah.controller.ProductController : product size must be between 2 and 150
#RequestMapping(path = "/product")
public class ProductController {
private static final Logger logger = LoggerFactory.getLogger(ProductController.class);
#Autowired
private ProductRepo productRepo;
.....
#RequestMapping(value = "/save", method = RequestMethod.POST)
public String save(#ModelAttribute #Valid Product product, Errors errors, Model model) {
if (errors.hasErrors()) {
model.addAttribute("product", new Product());
// logger.info("Error Message " + bindingResult.getGlobalErrorCount());
logger.info("Error Message " + errors.getFieldErrorCount());
List<ObjectError> err = errors.getAllErrors();
for (ObjectError e : err) {
logger.info(e.getObjectName() + e.getDefaultMessage());
}
// logger.info("Error Message " + bindingResult.getErrorCount());
return "/prod/create";
} else {
productRepo.save(product);
return "redirect:/product/list";
}
}
My Pojo
#Entity
public class Product {
#Id
#Column(name = "ProdID", updatable = false, nullable = false)
#GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "product_generator")
#SequenceGenerator(name="product_generator", sequenceName = "zseq_product", allocationSize=1)
private int ProdID;
#NotNull(message = "Field Product cannot be empty")
// #NotEmpty(message = "Field Product cannot be empty")
#Size(min = 2, max = 150)
private String name;
private String prodDesc;
My HTML
<form th:object="${product}" th:action="#{/product/save}" method="post">
.....
<div class="form-group"
th:classappend="${#fields.hasErrors('name')}? 'has-error'">
<label th:for="name" class="col-form-label">Product Name:</label>
<input type="text" class="form-control" th:field="*{name}" />
<span th:if="${#fields.hasErrors('name')}"
th:errors="*{name}"
th:class="help-block">Title Errors</span>
</div>