ajax请求发送json数据

前端代码

function submitHandler() {
        var data3 = {
            "enCode": 100,
            "enName": "2123",
            "flueNum": 2,
            "pipes": [
                {
                    "name": "123"
                    
                },
                {
                    "name": "124"
                }]
        };
        var data4=JSON.stringify(data3);

        if ($.validate.form()) {
            //新增
            $.ajax({
                url: prefix + "/add",
                type: "post",
                dataType: "json",
                contentType : 'application/json;charset=utf-8',
                data: data4,
                success: function (result) {
                    
                },
                error: {}
            });
        }
    }

　　后台接收

 @PostMapping("/add")
    @ResponseBody
    public AjaxResult addSave(@RequestBody Enter enter, HttpServletRequest request)
    {
        return toAjax(1);
    }

　　实体类

public class Enter extends BaseEntity
{
    private static final long serialVersionUID = 1L;

    /** null */
    private Long id;

    /** 编码 */
    @Excel(name = "编码")
    private Long enCode;

    /** 名称 */
    @Excel(name = "名称")
    private String enName;


    private List<Pipe> pipes;

…………
}