Thymeleaf - set attributes for objects in forms with hidden inputs - spring-boot

Question

I got this peace of html:
<form action="#" th:action="#{${cartServiceBaseUrl}+'/addCatalogItemToCart'}" th:object="${cartCatalogItem}" method="post">
<input type="hidden" th:value="${cartId}" th:field="*{cartId}" />
<input type="hidden" th:value="${catalogItem.catalogItemId}" th:field="*{catalogItemId}" />
<input type="submit" value="add to cart" />
</form>
Unfortunately both values are null and I dont really understand why, because both values, cartId and catalogItem.catalogItemId are available on the page.
How can I properly pass them?
Java endpoint
#PostMapping(ADD_CATALOG_ITEM_TO_CART)
public void addCatalogItemToCart(#ModelAttribute CartCatalogItem cartCatalogItem, HttpServletResponse response) {
Full HTML:
<h1 th:text="${catalog.name}">...</h1>
<a th:href="#{${customerServiceBaseUrl}+'/home/'+__${cartId}__}">home</a>
<p th:text="'Catalog ID:'+${catalog.catalogId}"></p>
<p th:text="'Name: '+${catalog.name}"></p>
<table>
<th:block th:each="catalogItem : ${catalog.catalogItems}">
<tr>
<th>article id</th>
<th>catalogitem id</th>
<th>name</th>
<th>price</th>
</tr>
<tr>
<td th:text="${catalogItem.articleId}">...</td>
<td th:text="${catalogItem.catalogItemId}">...</td>
<td th:text="${catalogItem.name}">...</td>
<td th:text="${catalogItem.price}">...</td>
<td><form action="#" th:action="#{${cartServiceBaseUrl}+'/addCatalogItemToCart'}" th:object="${cartCatalogItem}" method="post">
<input type="hidden" th:value="${cartId}" th:field="*{cartId}" />
<input type="hidden" th:value="${catalogItem.catalogItemId}" th:field="*{catalogItemId}" />
<input type="submit" value="add to cart" />
</form></td>
</tr>
</th:block>
</table>
My goal: assign attributes to objects with hidden input fields and pass them for the controller methods.

Answer 1

You are not set your values from controller that's why there are both values null.
Use this code on your controller.
For example:
Model and View model=new Model and View ("Your thyme leaf template name");
model.put('your key name by which you an access on your thyme leaf
page',cart Id);
return model;
This will work.