Question

我有两个类Student和Address。我使用hibernate作为ORM工具。我已经映射了多个到一个关系像许多学生一样的学生和地址可以有相同的地址。我的地址类是：

@Entity
Class Address {
@Id
@GeneratedValue
private int aid;
private String address;

@OneToMany(cascade = CascadeType.ALL)
@JoinColumn(name = "sid")
List<Student> students;
//getter and setter,constructor
}

我的学生班是：

@Entity
public class Student {
@Id
@GeneratedValue
private int sid;
private String sname;
//getter and setter,constructor
}

我的Address类的控制器类是：

public class AddressController {
@RequestMapping(value = "/address",method = RequestMethod.POST)
@ResponseBody
public String insertCategory(@RequestBody Address address) throws        SQLException {
    session=sessionFactory.getCurrentSession();
    session.save(address);
    return "succesful";
}

我将json数据插入：本地主机：8080 /地址

{"address":"kathmandu","students":[{"sname":"Pravin"},{"sname":"biplav"}]}

但问题是我想添加现有地址的学生。我想插入一个新的学生链接地址，但没有在地址表中插入新行。

我的地址类控制器是：

public class StudentController{
@RequestMapping(value = "/student",method = RequestMethod.POST)
@ResponseBody
public String insertCategory(@RequestBody Student student) throws   SQLException {
    session=sessionFactory.getCurrentSession();
    session.save(student);
    return "succesful";
}

我想插入：本地主机：8080 /学生

{"sname":"pravin","aid":"1"}

Answer 1

然后，您需要另一个REST端点将学生添加到地址。例如使用json学生申请机构发布http://localhost:8080/address/1/student。

您错过的链接是您要更新的地址的ID。

POST http://localhost:8080/address/1/student

请求正文：{"sname":"pravin"}

@POST
@Path("address/{addressId}/student")
public Response addStudentToAddress(@PathParam("addressId") Integer addressId, Student student)) {

   // Fetch address by id
   // Add student to list
   // Save updated address

}

正如您所看到的，我现在正在使用POST来“创建”新学生并将其添加到现有地址实体。

您拥有的其他选项是使用PUT更新地址（整个地址对象必须存在于请求正文中）或PATCH，您还可以更新资源，但只能使用您传递的字段（您必须自己写这个逻辑，显然）

PUT http://localhost:8080/address/1

请求正文：{"aid":"1","address":"kathmandu","students":[{"sid":"1","sname":"Pravin"},{"sid":"2", "sname":"biplav"}, {"sname":"Nico"}]}

@PUT
@Path("address/{addressId}")
public Response updateAddress(@PathParam("addressId") Integer addressId, Address address)) {

   // match addressId with address body id. throw exception if it does not match
   // Save updated address

}

PATCH http://localhost:8080/address/1

请求正文：{"aid":"1", "students":[{"sid":"1", "sname":"Pravin"},{"sid":"2", "sname":"biplav"}, {"sname":"Nico"}]}

我不会在此请求正文中传递"address":"katmandu"，因为我不想更新此字段。

@PATCH
@Path("address/{addressId}")
public Response updateAddress(@PathParam("addressId") Integer addressId, Address address)) {

   // match addressId with address body id. throw exception if it does not match
   // merge updated fields
   // Save updated address

}

如何将json数据插入到spring mvc和hibernate中与父表链接的子表中

1 个答案: