How to ignore specific fields on income in Spring boot? - spring

Question

I have my domain class as follows
#Getter
#Setter
public class Student {
private Long id;
private String firstName;
private String lastName;
}
And I have this controller
#RestController
#RequestMapping("/student")
public class StudentController {
#PostMapping(consumes = "application/json", produces = "application/json")
public ResponseEntity<Student> post(#RequestBody Student student) {
//todo save student info in db, it get's an auto-generated id
return new ResponseEntity<>(student, HttpStatus.CREATED);
}
}
Now what I want is to configure serializer in a way that it ignores the id field on income, so I get only firstName and lastName, but serialize it when I'm returning the object to the caller.

Answer 1

Its easy to use it with jackson. There is an annotation named #JsonProperty(access = Access.READ_ONLY) where you can define if the property should be de- or serialized. Just put that annotation on your id field.
#JsonProperty(access = Access.READ_ONLY)
private Long id;
The Controller:
#PostMapping(consumes = "application/json", produces = "application/json")
public ResponseEntity<Student> post(#RequestBody Student student) {
//here we will see the that id is not deserialized
System.out.println(student.toString());
//here we set a new Id to the student.
student.setId(123L);
//in the response we will see that student will serialized with an id.
return new ResponseEntity<>(student, HttpStatus.CREATED);
}
Requestbody:
{
"id":1,
"firstName": "Patrick",
"lastName" : "secret"
}
Output of toString():
Student [id=null, firstName=Patrick, lastName=secret]
Response:
{
"id": 123,
"firstName": "Patrick",
"lastName": "secret"
}
P.S. It will also work if you dont send an id property:
{
"firstName": "Patrick",
"lastName" : "secret"
}