将spring表单绑定到list元素

Question

Is it possible to bind spring form:form to a list element? I've tried this way.

<form:form commandName="products[0]">
   <form:input path="name"/>
</form:form>

also

<form:form commandName="products0">
   <form:input path="name"/>
</form:form>

Where products list is populated in spring controller.

@RequestMapping(method = RequestMethod.GET)
public String getAll(Map<String, Object> map) {
    map.put("products", productService.getAll());
    return "products";
}

Received: java.lang.IllegalStateException: Neither BindingResult nor plain target object for bean name 'products[0]' available as request attribute . Which as I understand means that spring haven't found where to bind the form.

Answer 1

No, this is not possible. The value you pass to the commandName attribute is a key and it is not resolved like a normal EL or SpEL expression would be. It is used directly. In other words, with

<form:form commandName="products[0]">
   <form:input path="name"/>
</form:form>

Spring will look for a model attribute called products[0] which it won't find.

The alternative is to put the first element of the list in the model directly with a key you will use in your jsp.

Or you can use JSTL, get the first element in the list and create an HTML <form> element yourself.