为什么System.out.println()语句中获得NULL?

我可以结合Ajax使用Spring表单标记库吗?我无法在控制器中成功检索表单输入参数,它们总是空的。

实际上,表单从来没有提交过,这是一种逻辑。但是,我只能向控制器发送字符串,而不能像映射到Spring commandBean的表单提交那样发送对象。

表单接受commandBean:

<form:form method="POST" commandName="clinicBean">
    Clinic Name: <form:input path="name" type="text" /><br/>
    Clinic Address: <form:input path="address" type="text"/><br/>
    <input type="button" value="Create Clinic" onclick="clinicAjax()"/>
</form:form>

Ajax函数调用Spring控制器:

function clinicAjax(){
    alert('Inside Clinic Ajax Method');
    $.ajax({
        url: 'clinicAjax',
        type: 'POST',
        success: alert('Ajax Successful')
    });
}

Spring Controller 方法:

@RequestMapping(value="clinicAjax",method=RequestMethod.POST)


 public @ResponseBody String createClinic(@ModelAttribute("clinicBean") Clinic clinic){
        System.out.println("Ajax call successful");
        System.out.println(clinic);
        System.out.println(clinic.getName());
        System.out.println(clinic.getAddress());
        return "SUCCESS";
    }

它总是在System.out.println()语句中获得NULL。

The problem is that you're not serializing your form anywhere so it's not being sent to the server.

Change your javascript code to:

function clinicAjax(){
    alert('Inside Clinic Ajax Method');
    $.ajax({
        url: 'clinicAjax',
        data: yourFormElement.serialize(); /* i.e. $('#formId').serialize(); */
        type: 'POST',
        success: alert('Ajax Successful')
    });
}

substitute yourFormElement with jQuery object representing your form and it should work.