service.createUser = function (user) {
    console.log("Service. Creating user ",user);
    return http({
        method: 'GET',
        url: '/user/createUser',
        contentType: 'application/json',
        data: {user: user}
    })
};

$scope.user = {
    firstName: "",
    lastName: "",
    email: "",
    password: "",
    roles: []
};

@RequestMapping(value = "/createUser", method = RequestMethod.GET)
public boolean createUser(@RequestBody UserDTO userDTO) {
    System.out.println(userDTO);
    return true;
}

public class UserDTO {

private Long id;
private String email;
private String firstName;
private String lastName;
private String password;
private List<Role> roles;

//getters and setters
}