下面是对我的控制器的ajax调用

$('#submitButton').on('click', function() {
            var expenseDetailsListVO = {};
            expenseDetailsListVO = getData();
            console.log(expenseDetailsListVO);
            var data = JSON.stringify(expenseDetailsListVO);
            console.log(data);
            $.ajax({
                url : "${pageContext.request.contextPath}/saveExpenses",
                data : data,
                method : 'POST',
                contentType : "application/json",
                success : function(data) {

                },
                error : function(data) {

                }
            });
        });

这是我的控制器

@RequestMapping (value = "/saveExpenses", method=RequestMethod.POST)
    public String saveExpenses (@RequestBody(required=false) ExpenseDetailsListVO expenseDetailsListVO, Model model) {


        //System.out.println("User Id is........ "+userId);
        System.out.println(expenseDetailsListVO);
        ExpenseDetailsList expenseDetailsList = MapperUtil.convertExpenseListVOToDO(expenseDetailsListVO);

        //expenseServiceManagement.addExpense(expenseDetailsList);

        return "addExpense";
    }

以下是我的Java类

public class ExpenseDetailsListVO {


    private List<ExpenseDetailsVO> expenseDetailsVOs = LazyList.decorate(
            new ArrayList<ExpenseDetailsVO>(),
            FactoryUtils.instantiateFactory(ExpenseDetailsVO.class));

public ExpenseDetailsListVO (){}

    public List<ExpenseDetailsVO> getExpenseDetailsVOs() {
        return expenseDetailsVOs;
    }

    public void setExpenseDetailsVOs(List<ExpenseDetailsVO> expenseDetailsVOs) {
        this.expenseDetailsVOs = expenseDetailsVOs;
    }

    @Override
    public String toString() {
        return "ExpenseDetailsListVO [expenseDetailsVOs=" + expenseDetailsVOs
                + "]";
    }

}



   public class ExpenseDetailsVO {

        /*private int expenseId;*/

        private String itemDescription;

        private double amount;

        private Date expenseDate;

public ExpenseDetailsVO (){}
        /*public int getExpenseId() {
            return expenseId;
        }

        public void setExpenseId(int expenseId) {
            this.expenseId = expenseId;
        }*/

        public String getItemDescription() {
            return itemDescription;
        }

        public void setItemDescription(String itemDescription) {
            this.itemDescription = itemDescription;
        }

        public double getAmount() {
            return amount;
        }

        public void setAmount(double amount) {
            this.amount = amount;
        }

        public Date getExpenseDate() {
            return expenseDate;
        }

        public void setExpenseDate(Date expenseDate) {
            this.expenseDate = expenseDate;
        }

        @Override
        public String toString() {
            return "ExpenseDetailsVO [itemDescription=" + itemDescription
                    + ", amount=" + amount + ", expenseDate=" + expenseDate + "]";
        }

    }

以前它可以正常工作，但是我进行了一些更改，使我不记得了，现在由于客户端发送的请求在语法上不正确，导致浏览器控制台出现错误

伙计们，请让我知道这是什么问题…