Spring Boot将null属性映射到来自angular2的JSON post请求的POJO

Question

在对这个话题做了大量的研究后，我决定在这里问这个问题。我将所有null属性都添加到pojo/model，它应该从我从Angular 2前端发布的JSON中获取值。下面是rest控制器方法：

@RequestMapping(value = "/employees/update",  method = RequestMethod.POST, consumes = "application/json")
    public String allEmployees( @RequestBody Employee emp){
        return "";
    } 

以下是POJO/Model/Hibernate实体：

@Id
@GeneratedValue(strategy = GenerationType.AUTO)
@Column(nullable = false, updatable = false)
private Long id;

private String firstname;
private String lastname;
private String department;

public Employee(){}

public Long getId() {
    return id;
}
public void setId(Long id) {
    this.id = id;
}
public String getFirstname() {
    return firstname;
}
public void setFirstname(String firstname) {
    this.firstname = firstname;
}
public String getLastname() {
    return lastname;
}
public void setLastname(String lastname) {
    this.lastname = lastname;
}
public String getDepartment() {
    return department;
}
public void setDepartment(String department) {
    this.department = department;
}

以下是Angular 2的服务方法：

updateEmployee(emp:Employee){
  let url: string = "http://localhost:8080/api/employees/update";
  let headers = new Headers();
  headers.append('Content-Type', 'application/json');
  return  this.http.post(url, {emp}, {headers: headers, withCredentials: true }).map(res => res.json());
}

和Angular 2的员工界面：

export interface Employee{
  id: number;
  firstname: string;
  lastname: string;
  department: string;
}

我做错了什么？我搜索过类似的问题，但没有一个适用于我的情况。谢谢！

Answer 1

尝试用@ResponseBody注释该方法

它将变成：

@ResponseBody
@RequestMapping(value = "/employees/update",  method = RequestMethod.POST, consumes = "application/json")
    public String allEmployees( @RequestBody Employee emp){
        return "";
    }