Uncaught TypeError:Cannot read property ‘code‘ of undefinedn

报错：使用dtree树形结构报错

报错代码：

解决代码:

// 初始化树
var DemoTree = dtree.render({
    elem: "#deptLeftTree",
    dataStyle:"layuiStyle",
    dataFormat:"list",  //配置data的风格为list
    response:{message:"msg",statusCode:0},  //修改response中返回数据的定义
    url:"/dept/buildLeftTree", // 使用url加载（可与data加载同时存在）
    checkbar:true //开启复选框
});

后台代码: 定义一个类

package com.fh.common;

import lombok.AllArgsConstructor;
import lombok.Data;
import lombok.NoArgsConstructor;

@Data
@AllArgsConstructor
@NoArgsConstructor
public class DeptNode {
    private Integer id;
    private Integer parentId;
    private String title;

    public DeptNode(Integer id, Integer parentId, String title) {
        this.id = id;
        this.parentId = parentId;
        this.title = title;
    }
}

控制器代码：

package com.ff.controller;
import com.ff.common.DataGridView;
import com.ff.common.DeptNode;
import com.ff.domain.Dept;
import com.ff.service.DeptService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

import java.util.ArrayList;
import java.util.List;

@RestController
@RequestMapping("dept")
public class DeptController {

    @Autowired
    private DeptService deptService;


    @RequestMapping("buildLeftTree")
    public DataGridView buildLeftTree(){

      List<Dept>deptList=deptService.queryDeptList();

      List<DeptNode>treeNodeList = new ArrayList<>();
        for (Dept dept : deptList) {
            treeNodeList.add(new DeptNode(dept.getId(),dept.getPid(),dept.getTitle()));
        }
        return new DataGridView(treeNodeList);
    }
}