从JSP表单发送<option>值到Controller Spring MVC

Question

这是我在JSP文件中的表单：

    <p class="lead">Check out the books in my store...</p>

    <form:form action="${pageContext.request.contextPath}/bookListByCategory"> 
    <select path="category">
        <option value="Programming">Programming</option>
        <option value="Fiction">Fiction</option>
        <option value="Biography">Biography</option>
        <option value="Travel">Travel</option>
    </select>
    <input type="submit" name="submit" value="submit" />
    </form:form>

表单将发送到方法：

@RequestMapping(value = "/bookListByCategory/{category}")
public String getBooksByCategory(@PathVariable String category, Model model) {
    List<Book> bookListByCategory = bookService.getBookListByCategory(category);
    model.addAttribute("books", bookListByCategory);
    model.addAttribute("category", category);
    return "bookList";
}

出于某种原因，它无法正常工作，我可以在浏览器中看到以下内容：

当我点击＆＃34;提交＆＃34;它将显示404：

我可以看到所选选项的值不会发送到Controller，而Controller是处理请求所必需的。有什么想法吗？

Answer 1

现在的工作表格：

<form action="${pageContext.request.contextPath}/bookListByCategory"> 
    <select name="category" onchange="this.form.submit();">
        <option value="all">-- category --</option>
        <option value="Programming">Programming</option>
        <option value="Fiction">Fiction</option>
        <option value="Biography">Biography</option>
        <option value="Travel">Travel</option>
    </select>
</form>

控制器中还有两种方法：

@RequestMapping(value = "/bookListByCategory/{category}")
public String getBooksByCategory(@PathVariable String category, Model model) {
    List<Book> bookListByCategory = bookService.getBookListByCategory(category);
    model.addAttribute("books", bookListByCategory);
    model.addAttribute("category", category);
    return "bookList";
}

@RequestMapping(value = "/bookListByCategory")
public String getBooksByCategoryForm(@ModelAttribute("category") String category, 
        Model model) {
    if (category.equalsIgnoreCase("all")) {
        return "redirect:/bookList/";
    } else {
        return "redirect:/bookListByCategory/" + category;          
    }
}

一切正常，并产生所需的输出。

Answer 2

我将举例说明如何向mvc控制器发送选项。

所以在jsp中说你有这个 -

请注意，我在此使用了<form:select/>而不是select。

<form:form action="bookListByCategory" method="get">
  <form:select path="category">
    <form:option value="NONE"> --SELECT--</form:option>
    <form:options items="${listOfCategories}"></form:options>
  </form:select>
  ...
</form:form>

现在使用RequestParam

在控制器中

@RequestMapping(value = "/bookListByCategory", method = RequestMethod.GET)
public String getBooksByCategory(@RequestParam String category, Model model)
    throws Exception {

       //rest of code ....

}