如何将Ajax中的FormData和JSON对象传递给Spring MVC Controller？

我需要在ajax调用中同时传递FormData和JSON对象，但是却收到400 Bad Request错误。

[artifact:mvn]  org.springframework.web.servlet.mvc.support.DefaultHandlerExceptionResolver - Failed to read HTTP message: org.springframework.http.converter.HttpMessageNotReadableException: Could not read document: Unexpected character ('-' (code 45)) in numeric value: expected digit (0-9) to follow minus sign, for valid numeric value
[artifact:mvn]  at [Source: java.io.PushbackInputStream@3c0d58f6; line: 1, column: 3]; nested exception is com.fasterxml.jackson.core.JsonParseException: Unexpected character ('-' (code 45)) in numeric value: expected digit (0-9) to follow minus sign, for valid numeric value
[artifact:mvn]  at [Source: java.io.PushbackInputStream@3c0d58f6; line: 1, column: 3]

JS：

var formData = new FormData(form[0]);
//form JSON object
var jsonData = JSON.stringify(jcArray);
$.ajax({
        type: "POST",
        url: postDataUrl,
        data: { formData:formData,jsonData:jsonData },
        processData: false,
        contentType: false,
        async: false,
        cache: false,
        headers: { 
            'Accept': 'application/json',
            'Content-Type': 'application/json' 
        },
        success: function(data, textStatus, jqXHR) {
        }
});

控制器：

@RequestMapping(value="/processSaveItem",method = RequestMethod.POST")
public @ResponseBody Map<String,String> processSaveItem(
                                  @RequestBody XYZClass result[])

}

有一个类似的问题，jQuery在ajax调用中发送表单数据和json对象，而我正在尝试相同的方法。

如何在单个ajax请求中同时发送FormData和JSON对象？