How to rename json objects(variables) name in spring boot - json

Question

Hello I am new to spring boot and JSON and need help in renaming the variable name coming in response.
Consider this as a input
"1": {
"id": "1",
"firstName": "Cdgdghirayu",
"lastName": "Sinfsdgdgghvi",
"age": 23
}
Now in respone I need in this format
"1": {
"Roll number": "1",
"firstName": "Cdgdghirayu",
"lastName": "Sinfsdgdgghvi",
"age": 23
}
can we map "id" to "roll number" in some way?
How to achieve this in spring-boot?
Thanks in advance
upadte-
This is my model class
package model;
import javax.xml.bind.annotation.XmlRootElement;
import com.fasterxml.jackson.annotation.JsonProperty;
#XmlRootElement
public class Person {
#JsonProperty("Roll Number")
private String id;
private String firstName;
private String lastName;
private int age;
public Person() {
super();
}
public Person(String id, String firstName, String lastName, int age) {
super();
this.id = id;
this.firstName = firstName;
this.lastName = lastName;
this.age = age;
}
public String getId() {
return id;
}
public void setId(String 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 int getAge() {
return age;
}
public void setAge(int age) {
this.age = age;
}
}
This is my service class
Here in addPerson() function I have to set id as its taking id as null..
package service;
import java.util.Hashtable;
import org.springframework.stereotype.Service;
import model.Person;
#Service
public class PersonService {
Hashtable<String,Person> persons=new Hashtable<String,Person>();
public PersonService(){
Person p=new Person();
p.setId("1");
p.setFirstName("Chirayu");
p.setLastName("Singhvi");
p.setAge(23);
persons.put("1",p);
p=new Person();
p.setId("2");
p.setFirstName("Himanshu");
p.setLastName("Singhvi");
p.setAge(20);
persons.put("2",p);
}
public Person getPerson(String id){
if(persons.containsKey(id))
return persons.get(id);
else return null;
}
public Hashtable<String,Person> getAll(){
return persons;
}
public Person addPerson(Person person){
persons.put(person.getId(),person);
return person;
}
public Person updatePerson(Person person){
if(person.getId().equals("0")){
return null;
}
persons.put(person.getId(),person);
return person;
}
public Person removePerson(String id) {
return persons.remove(id);
}
My controller class
package controller;
import java.util.Hashtable;
import org.apache.log4j.Logger;
import org.apache.log4j.PropertyConfigurator;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.http.MediaType;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RequestBody;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import org.springframework.web.bind.annotation.ResponseBody;
import org.springframework.web.bind.annotation.RestController;
import com.fasterxml.jackson.databind.annotation.JsonNaming;
import model.Person;
import service.PersonService;
#RestController
#RequestMapping("/persons")
public class PersonController {
static final Logger log = Logger.getLogger(PersonController.class.getName());
PersonController(){
log.info("entering controller class");
}
#Autowired
PersonService personService;
#RequestMapping("/all")
public Hashtable<String,Person> getAll(){
log.info("getting all person details");
System.out.println("syso is working");
return personService.getAll();
}
#RequestMapping(value="/all",method=RequestMethod.POST,
produces=MediaType.APPLICATION_JSON_VALUE,
consumes=MediaType.APPLICATION_JSON_VALUE )
#ResponseBody
public Person addPerson(#RequestBody Person person){
log.info("Adding person with id "+person.getId());
person.getId();
return personService.addPerson(person);
}
#RequestMapping(value="/{id}",method=RequestMethod.PUT,
produces=MediaType.APPLICATION_JSON_VALUE,
consumes=MediaType.APPLICATION_JSON_VALUE )
#ResponseBody
public Person updatePerson(#PathVariable("id") String id,
#RequestBody Person person){
person.setId(id);
log.info("Updating a partcular person details with id "+id);
return personService.updatePerson(person);
}
#RequestMapping(value="/{id}",method=RequestMethod.DELETE)
public void removePerson(#PathVariable("id") String id){
log.info("Removing the person details with id "+id);
personService.removePerson(id);
}
#RequestMapping("/{id}")
public Person getPerson(#PathVariable("id") String id){
log.info("getting person details with id "+id);
return personService.getPerson(id);
}
public void setDthDao(PersonService dao) {//for testing purpose
personService=dao;
}
Now in SOAPUI testing(writing text as snapshots are not uploading)
for GET request : endpoint-http://localhost:8080 :Resource-/persons/all
response-
{
"2": {
"firstName": "Himanshu",
"lastName": "Singhvi",
"age": 20,
"Roll Number": "2"
},
"1": {
"firstName": "Chirayu",
"lastName": "Singhvi",
"age": 23,
"Roll Number": "1"
}
}
Now for Post- : endpoint-http://localhost:8080 :Resource-/persons/all
Mediatype-
{
"firstName": "Rahul",
"lastName": "Jain",
"age": 23,
"id": "6"
}
Response what I am getting
{
"timestamp": 1469790685110,
"status": 500,
"error": "Internal Server Error",
"exception": "java.lang.NullPointerException",
"message": "No message available",
"path": "/persons/all"
}
Response that I want
{
"firstName": "Rahul",
"lastName": "Jain",
"age": 23,
"Roll number": "6"
}

Answer 1

Assuming you have a getter method for the id property, you can try adding the com.fasterxml.jackson.core dependency to your project and annotating your method like this:
#JsonProperty("Roll Number")
public Long getId () {
return id;
}

Answer 2

Finally got it right
just made following changes in my model class.
#JsonProperty("Roll Number")
private String id;
#JsonProperty("Roll Number")
public String getId() {
return id;
}
#JsonProperty("id")
public void setId(String id) {
this.id = id;
}