Spring Boot & Thymeleaf，将变量传递给控制器

Question

I have a controller that processes the purchase of a product,it takes two parameters,count - the quantity of the product and id - the ID of the product that the user buys.

@PostMapping("/buyproduct")
public String buyProduct(@RequestParam int count,@RequestParam long id){
    Product product = productRepository.findById(id);
    int activeCount = product.getCount();
    if (activeCount-count<0){
        return "redirect:/";
    }
    product.setCount(activeCount-=count);
    productRepository.save(product);
    return "redirect:/buyproductsuccessful";
}

In index.html I have listed all available products in the database using Thymeleaf.

<div class="col-12 col-md-6 col-lg-4" th:each="element : ${products}">
        <div class="card">
            <img class="card-img-top" src="https://picsum.photos/362/180" alt="Card image cap">
            <div class="card-body">
                <h5 style="text-align: center" class="card-title" th:text="${element.getName()}"</h5>
                <span th:text="${element.getCost()}"></span></p>
                <span th:text="${element.getCount()}"></span> </p>
                ...

Each product has its own button,when clicked, a popup opens in which you need to enter the quantity of the purchased product and Bank data (I don't process them, I don't Need them yet), and there is also a hidden field in which I want to put the product ID so that it can be passed to the controller later.

<form action="#" th:action="@{/buyproduct}" th:object="${element}" method="post">
                                <!-- Modal Header -->
                                <div class="modal-header">
                                    <h4 class="modal-title" style="color: #368819"></h4>
                                    <button type="button" class="close" data-dismiss="modal">&times;</button>
                                </div>

                                <!-- Modal body -->
                                <div class="modal-body">
                                    <div>
                                        <input type="hidden" name="id" th:value="*{getId()}">
                                        <label><b>რაოდენობა</b></label><br>
                                        <input class="col-4" type="number" min="1" value="1" name="count" required><br><br>
                                        <label><b></b></label><br>
                                        <input class="col-12" type="text"><br><br>
                                        <label><b></b></label><br>
                                        <input class="col-12" type="date"><br><br>
                                        <label><b>CVV/CVC</b></label><br>
                                        <input class="col-4" type="text"><br><br>
                                    </div>
                                </div>

                                <!-- Modal footer -->
                                <div class="modal-footer">
                                    <button type="submit" class="btn btn-success"></button>
                                    <button type="button" class="btn btn-danger" data-dismiss="modal"></button>
                                </div>
                                </form>

But Thymeleaf passes the id of the first product every time,what is my mistake?

Answer 1

The problem was with Bootstrap modal scopes.

<button style="margin-left: 40%" type="button" class="btn btn-success" data-toggle="modal" data-target="#myModal">
<div class="modal" id="myModal">

After fix its looks like this.

<button style="margin-left: 40%" type="button" class="btn btn-success" data-toggle="modal" th:attr="data-target='#id-' + ${element.getId()}">
<div class="modal" th:id="'id-' + ${element.getId()}">