1) You need to difine your rest controllers. Example
@Autowired
UserService userService;
@RequestMapping(value = "/user/", method = RequestMethod.GET)
public ResponseEntity<List<User>> listAllUsers() {
List<User> users = userService.findAllUsers();
if (users.isEmpty()) {
return new ResponseEntity(HttpStatus.NOT_FOUND);
}
return new ResponseEntity<List<User>>(users, HttpStatus.OK);
}
2) Define your pojo: Example
public class User {
String name;
String age;
public User(String name, String age) {
this.name = name;
this.age = age;
}
public String getName() {
return name;
}
public String getAge() {
return age;
}
}
3) Define a service
@Service
public class UserService {
public List<User> findAllUsers(){
// Those are mock data. I suggest to search for Spring-data for interaction with DB.
ArrayList<User> users = new ArrayList<>();
User user = new User("name", "5");
users.add(user);
return users;
}
}
You can follow this tutorial. If you want to just send a json message to a spring boot rest controller you can use a rest client like postman.