spring - JSP 表单 : HttpStatus 400: The request sent by the client was syntactically incorrect

Question

我在 jsp 中有这个:

<form:form method="POST" modelAttribute="answer">
	<table>
		<tr>
			<td><label for="chosenanswer">answer: </label> </td>
			<td>
				<form:radiobutton path="chosenAnswer" value="Male" />Male
				<form:radiobutton path="chosenAnswer" value="Female" />Female
				<form:radiobutton path="chosenAnswer" value="Other" />Other 
			</td>
	    </tr>

当我点击提交按钮时，我收到一个 HTTPStatus 400 消息:

 The request sent by the client was syntactically incorrect.

这是我的 Controller 类中的内容:

@RequestMapping(value = { "/take-exam-{examid}" }, method = RequestMethod.GET)
public String takeExam(@PathVariable String examid, ModelMap model) {
    model.addAttribute("answer",new SelectedAnswer());
    model.addAttribute("questiontext","Dummy question text");
    return "exam";
}

/*
 *Answering a question
 */
@RequestMapping(value = { "/take-exam-{examid}" }, method = RequestMethod.POST)
public String answerQuestion(SelectedAnswer answer, BindingResult result,
        ModelMap model, @PathVariable String ssn) {

    model.addAttribute("answer", "SelectedAnswer: "+answer.toString());
    model.addAttribute("success", "SelectedAnswer: "+answer.toString());
    return "success";
}

我的 SelectedAnswer 类是:

public class SelectedAnswer {
    private String chosenAnswer;

    public String getChosenAnswer() {
        return chosenAnswer;
    }

    public void setChosenAnswer(String chosenAnswer) {
        this.chosenAnswer = chosenAnswer;
    }

    public String toString()
    {
        return "SelectedAnswer = "+chosenAnswer;
    }
}

页面加载正常，但是当我点击提交按钮时，出现 HttpStatus 400 错误:客户端发送的请求在语法上不正确。知道发生了什么事吗？

谢谢，

问候，塞尔维亚语

Answer 1

为什么answerQuestion方法中有ssn参数？尝试将其更改为考试