怎么解决org.springframework.beans.InvalidPropertyException这个异常？

说我这个属性无效、不合法的，没有定义的

org.springframework.beans.InvalidPropertyException: Invalid property 'FEntity[0][FInspectionStandard]' of bean class [com.shunda.light.model.InspectionPlan]

controller是有定义对象的，结果在controller就报上面的错了

public ServerResponse save(InspectionPlan inspectionPlan){
    ServerResponse serverResponse = xjService.sumbit(inspectionPlan);
    return serverResponse;
}

InspectionPlan 对象有个属性是private List<FEntity> FEntity;FEntity对象属性FInspectionStandard的get/set方法也有，名字也取跟前端一样。但提交就报错了。请问这是怎么回事？

js请求是这样的

let FEntity = [];
for(let i=0,len=that.FXJXMS.length;i<len;++i){
    let item = {};
    item.FXJXM = that.FXJXMS[i].FXJXM;
    item.FInspectionStandard = that.FXJXMS[i].FInspectionStandard;
    item.F_STKD_Weight = that.FXJXMS[i].F_STKD_Weight;
    item.FIsNormal = "true";
    item.FInspectionState = "1";
    FEntity.push(item);
}
axios.post('/xj/save',{
    'FCheckplanID': that.FXJXMS[0].FCheckplanID,
    'FInspectionLocationID': that.FXJXMS[0].FInspectionLocationID,
    'FInspectionPlaceID': that.FXJXMS[0].FInspectionPlaceID,
    'FXJTypeId': that.FXJXMS[0].FXJTypeId,
    'FXJType': that.FXJXMS[0].FXJType,
    'FRate': that.FXJXMS[0].FRate,
    'FRateUnit': that.FXJXMS[0].FRateUnit,
    'FDate': FDate,
    'FEntity': FEntity,
},{
    headers: {
        'Content-Type': 'application/x-www-form-urlencoded'
    }
}).then(function (res) {
    console.log(res.data)
});