如何在SpringMVC中向控制器获取表单值

我试图在SpringMVC中从jsp获取表单值到控制器，但无法获取表单数据

这是我的DTO（bean）

和我的Jsp

<form class="form-signin" action="test" method="get" modelAttribute="userFormData">
     <input type="text" class="form-control" 
           placeholder="Email" required autofocus>

     <input type="password" class="form-control" 
           placeholder="Password" required>

     <input class="btn btn-md btn-success btn-block" 
           type="submit" value="Signin">
</form>

---

向JSP页面上的控件添加名称

<input type="text" name="username" ...>
<input type="password" name="password" ...>

让spring了解哪个表单控件值应该转到

LoginDTO的哪个属性

我们还可以使用springframework为我们提供的表单标记。因此，我们也可以使用它，但在这种情况下，您必须定义与类中提供的成员变量相同的输入路径

像这样

<form:form method="post" modelAttribute="userFormData">
    <form:input path="username" />
    <form:input path="password" />

如果您希望在其他jsp页面以及控制台上获得结果，请执行以下操作：

public String checkLogin(@ModelAttribute("userFormData") LoginDTO formData, BindingResult 
result , Model model){
    System.out.println("=====>  " + formData.getUsername()); //this outputs username on console
    System.out.println("=====>  " + formData.getPassword()); //this outputs password on console
    model.addAttribute("LoginDTO ", LoginDTO );
    return "success"; //this is the return page where the username and password will be rendered as view
}

<form:form method="post" modelAttribute="userFormData">
    <form:input path="username" />
    <form:input path="password" />

public String checkLogin(@ModelAttribute("userFormData") LoginDTO formData, BindingResult 
result)

public String checkLogin(@ModelAttribute("userFormData") LoginDTO formData, BindingResult 
result , Model model){
    System.out.println("=====>  " + formData.getUsername()); //this outputs username on console
    System.out.println("=====>  " + formData.getPassword()); //this outputs password on console
    model.addAttribute("LoginDTO ", LoginDTO );
    return "success"; //this is the return page where the username and password will be rendered as view
}