我在jsp文件中有一个发布请求：

<form method="post" action="http://localhost:8081/MerchantMovieTheater/api/movieTheater">
    <input type="hidden" name="balance" id="balance" value="${balance}"/>
    <input type="submit" value="Merchant Site">
</form>

相应的控制器是：

@RequestMapping(value = "movieTheater", method = RequestMethod.POST)
    public String submitTransaction(Model model, @RequestParam("balance") Double balance){
}

但是，当我执行jsp时，出现以下错误：

HTTP Status 400:  The request sent by the client was syntactically incorrect (Required Double parameter 'balance' is not present).

您能指出我哪里错了吗？提前致谢！