关于用SpringBoot创建RestApi时，发出请求返回json内容为空，只有一对大括号的问题

下面是出现问题的与RestApi相关的代码片段：

Controller中一个接口方法：

    @RequestMapping(value = "/employees")
    public ResponseEntity<EmployeeListVO> getAllEmployees()throws CloneNotSupportedException{
        EmployeeListVO employeeListVO;
        employeeListVO=(EmployeeListVO)EmployeeDB.getEmployeeList().clone();
        return new ResponseEntity<>(employeeListVO,HttpStatus.OK);
    }

EmployeeListVO.class:

public class EmployeeListVO implements Serializable,Cloneable {
    List<EmployeeVO>employees
            = new ArrayList<>();
    List<EmployeeVO>getEmployees(){
        return employees;
    }
    public void setEmployees(List<EmployeeVO>employees){
        this.employees = employees;
    }
}

问题代码出现在EmployeeListVO.class中：

我推测的原因是由于对于employees的getter方法不是public的，返回对象的时候springboot找不到此方法因此其中值自然为空;本人新手未研究源码，如果有知道的大佬还望赐教。

附：

public – accessible everywhere

protected – accessible in the same package and in sub-classes

default – accessible only in the same package

private – accessible only in the same class