我有一个springboot应用程序，当我从postman发布JSON时，我得到了null值。

Springboot文件：

`package com.learnspringboot.demo.controller;

import com.learnspringboot.demo.entity.Department;
import com.learnspringboot.demo.service.DepartmentService;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
public class DepartmentController {

    @Autowired
    private DepartmentService departmentService;

    @PostMapping("/departments")
    public Department saveDepartment(@RequestBody Department department){
       ** System.out.println(department.toString());**
        return departmentService.saveDepartment(department);
    }

    @GetMapping("/departments")
    public List<Department> fetchDepartment(){
        return departmentService.fetchDepartment();
    }

    @DeleteMapping("/departments/{Id}")
    public String deleteDepartment(@PathVariable("Id") Long DepartmentId){
        departmentService.deleteDepartment(DepartmentId);
        return "Department Id: "+ DepartmentId +" Deleted Successfully";
    }
}
`

字符串
Springboot console logs
Postman Request的
任何解决此问题的建议将受到高度赞赏。
我试着用实际的IP替换它，但它不起作用。