how to use javax.validation with Thymeleaf - validation

Question

When I run this it will create a new book if valid however upon error it will not post back to the page and I get a 400:
This application has no explicit mapping for /error, so you are seeing this as a fallback.
There was an unexpected error (type=Bad Request, status=400).
Validation failed for object='book'. Error count: 4
I tested with system outs, it never gets to the submit if it has errors, I think maybe #Valid is wrong or ???
This is my controller... please tell me what's missing ?
#Controller
#RequestMapping("/")
public class BookController{
#RequestMapping(method=RequestMethod.GET)
public String home(Model model) {
refData = new ReferenceData();
model.addAttribute("refData", refData);
model.addAttribute("book", new Book());
List<Book> books = BookRepo.findAll();
model.addAttribute("books", books);
return "home";
}
#RequestMapping(method=RequestMethod.POST)
public String submit(#Valid Book book,Model model, BindingResult bindingResult) {
refData = new ReferenceData();
model.addAttribute("refData", refData);
if (bindingResult.hasErrors()) {
return "home";
}
BookRepo.save(book);
return "redirect:/";
}
My form looks like this...
<form name="addForm" action="#" th:action="#{/}" th:object="${book}" method="post">
<table>
<tr>
<td><label for="*{title}">Book:</label></td>
<td><input type="text" th:field="*{title}" /></td>
<td th:if="${#fields.hasErrors('title')}" th:errors="*{title}">Name
Error</td>
</tr>
<tr>
<td><label for="*{author}">Author:</label></td>
<td><input type="text" th:field="*{author}" /></td>
<td th:if="${#fields.hasErrors('author')}" th:errors="*{author}">Author
Error</td>
</tr>
<tr>
<td><label for="*{genre}">Genre:</label></td>
<td><input type="text" th:field="*{genre}" /></td>
<td th:if="${#fields.hasErrors('genre')}" th:errors="*{genre}">genre
Error</td>
</tr>
<tr>
<td><label for="*{pages}">Pages:</label></td>
<td><input type="text" th:field="*{pages}" /></td>
<td th:if="${#fields.hasErrors('pages')}" th:errors="*{pages}">pages
Error</td>
</tr>
<tr>
<td><label th:for="*{year}">Year:</label></td>
<td>
<select th:field="*{year}" ng-model="bookData.year">
<option th:each="selectItem: ${refData.years}"
th:value="${selectItem.value}" th:text="${selectItem.label}">year</option>
</select>
</td>
<td th:if="${#fields.hasErrors('year')}" th:errors="*{year}">year
Error</td>
</tr>
<tr>
<td><label th:for="*{rating}">Rating:</label></td>
<td><select th:field="*{rating}" ng-model="bookData.rating">
<option th:each="selectItem: ${refData.rating}"
th:value="${selectItem.value}" th:text="${selectItem.label}">rating</option>
</select></td>
<td th:if="${#fields.hasErrors('rating')}" th:errors="*{rating}">rating
Error</td>
</tr>
<tr>
<td><button type="submit">Submit</button></td>
</tr>
</table>
</form>
my entity...
#Entity
public final class Book
{
#Id
#GeneratedValue(strategy = GenerationType.AUTO)
private Integer id;
#NotNull
#Pattern(regexp="^[a-zA-Z0-9_]+$")
private String title;
#NotNull
#Pattern(regexp="^[a-zA-Z0-9_]+$")
private String author;
#NotNull
#Pattern(regexp="^[a-zA-Z0-9_]+$")
private String genre;
#NotNull
#Digits(message="message here", integer=32767, fraction = 0)
private Integer pages;
private String year;
private String rating;

Answer 1

I found I had to place the bindingResult directly after the #Valid Book entity thus...
#RequestMapping(method=RequestMethod.POST)
public String submit(#Valid Book book,**BindingResult bindingResult**, Model model ) {
refData = new ReferenceData();
model.addAttribute("refData", refData);
if (bindingResult.hasErrors()) {
return "home";
}
BookRepo.save(book);
return "redirect:/";
}
Wow what a minor=major mistake !!
Johnny O.