TempFile

SampleCode.dart

import 'dart:convert';
import 'package:http/http.dart' as http;

void main() async {
  var empResponse = await getEmployeeById(256);
  if(empResponse.employee != null){
    print("EMPLOYEE NAME: "+empResponse.employee.name);
  }else{
    print("EMPLOYEE DOES NOT EXIST");
  }
}

Future<EmployeeResponse> getEmployeeById(int id) async {
  try{
    var response = await http.get(Uri.parse("example.com/api/emp/${id}"));
    if(response.statusCode == 200){
      var data = json.decode(response.body);
      return EmployeeResponse.fromMap(data);
    }else{
      return EmployeeResponse();
    }
  } catch(e) {
    return EmployeeResponse();
  }
}

class EmployeeResponse {
    EmployeeResponse({
        this.employee,
    });

    final Employee? employee;

    factory EmployeeResponse.fromMap(Map<String, dynamic> json) => EmployeeResponse(
        employee: json["employee"] == null ? null : Employee.fromMap(json["employee"]),
    );
}

class Employee {
    Employee({
        required this.name,
        required this.age,
        required this.joinYear,
    });

    final String name;
    final int age;
    final String joinYear;

    factory Employee.fromMap(Map<String, dynamic> json) => Employee(
        name: json["name"],
        age: json["age"],
        joinYear: json["join_year"],
    );
}