Integrating Rakuten API with Quartz.Net for Scheduling jobs using Windows Service

Recently one of my clients started using Rakuten E-commerce market place and wanted to develop a solution to run scheduled jobs at regular intervals for accessing the Rakuten API for tasks like updating stock information, fetching orders, updating shipment status for the orders etc.
The API is fairly well documented and is REST based, simple to understand. So I am going to show how we can work with Rakuten E-commerce market place API along side Quartz.Net for building Scheduled Jobs that will run inside a windows service.

Setup:
To start using Rakuten, You must request a license to use the Rakuten Marketplace Web Services Development Platform. Contact Rakuten Support to request your license. Rakuten assigns an authentication key to you containing your encoded credentials. This value must be used in each of your HTTP Request Headers to authorize your requests. Some of the other settings that we require to access the Rakuten API are:

• Rakuten Service API Endpoint: https://api.rms.global.rakuten.com/1.0/
• Marketplace Identifier: UK
• Shop URL: This is the URL for your website on Rakuten market place

I have used Visual Studio 2015 to develop this Windows Service.

Creating a HTTPClient with Authorization header to make API requests:
We will be using this HttpClient to make Rest based API requests to the Rakuten API

private HttpClient GetHttpClient()
{
    var client = new HttpClient();
    var authenticationKey = ConfigurationHelper.GetValue("AuthenticationKey");
    client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("ESA", authenticationKey);
    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
    return client;
}

Helper classed used:

namespace RakutenIntegrationService.Helpers
{
    public static class CronHelper
    {
        public static string GetCronExpression(double interval)
        {
            return string.Format("0 0/{0} * 1/1 * ? *", interval);
            //return "0 43 16 ? * *";
        }
    }
}

using System;
using System.Configuration;

namespace RakutenIntegrationService.Helpers
{
    public static class ConfigurationHelper
    {
        public static TResult GetValue<TResult>(string key)
        {
            var setting = ConfigurationManager.AppSettings[key];
            if (string.IsNullOrEmpty(setting))
                return default(TResult);
            var result = Convert.ChangeType(setting, typeof(TResult));
            return (TResult)result;
        }
    }
}

And then define a RestService class that contains methods to make GET and POST requests using this HttpClient

using System;
using System.Net;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text;
using Common.Logging;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using RakutenIntegrationService.Helpers;

namespace RakutenIntegrationService.Services
{
    public class RestService : IRestService
    {
        #region Fields

        private ILog Log = LogManager.GetLogger<RestService>();

        #endregion

        #region IRestService members

        public TResult Get<TResult>(string uriString) where TResult: class
        {
            var uri = new Uri(uriString);
            using (var client = GetHttpClient())
            {
                HttpResponseMessage response = client.GetAsync(uri).Result;
                if (response.StatusCode != HttpStatusCode.OK)
                {
                    Log.Error(response.ReasonPhrase);
                    return default(TResult);
                }
                var json = response.Content.ReadAsStringAsync().Result;
                return JsonConvert.DeserializeObject<TResult>(json, new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver() });
            }
        }

        public TResult Post<TResult, TInput>(string uriString, TInput payload = null) where TInput : class
        {
            var uri = new Uri(uriString);
            using (var client = GetHttpClient())
            {
                var jsonContent = JsonConvert.SerializeObject(payload, Formatting.Indented, new JsonSerializerSettings { ContractResolver = new CamelCasePropertyNamesContractResolver()});
                HttpResponseMessage response = client.PostAsync(uri, new StringContent(jsonContent, Encoding.UTF8, "application/json")).Result;
                if (response.StatusCode != HttpStatusCode.OK)
                {
                    Log.Error(response.ReasonPhrase);
                    return default(TResult);
                }
                var json = response.Content.ReadAsStringAsync().Result;
                return JsonConvert.DeserializeObject<TResult>(json);
            }
        } 

        #endregion
    }
}

Configuring Quartz.Net to create Scheduled jobs for API operations
So I installed Quartz.Net using nuget package manager: https://www.nuget.org/packages/Quartz/. Afterwards I created a class called TaskScheduler that basically configures the Scheduled Jobs creation and is responsible for Running/ Stopping the Quartz scheduler

using Quartz;
using RakutenIntegrationService.Helpers;
using RakutenIntegrationService.Jobs;

namespace RakutenIntegrationService.Scheduler
{
    public class TaskScheduler : ITaskScheduler
    {
        #region Private fields

        private readonly IScheduler _scheduler;

        #endregion

        #region Constructors

        public TaskScheduler(IScheduler scheduler)
        {
            _scheduler = scheduler;
        }

        #endregion

        #region ITaskScheduler members

        public string Name
        {
            get { return this.GetType().Name; }
        }

        public void Run()
        {
            ScheduleGetOrdersJob();
            ScheduleStockUpdateJob();
            ScheduleShipmentUpdateJob();

            _scheduler.Start();
        }

        public void Stop()
        {
            if (_scheduler != null) _scheduler.Shutdown(true);
        }

        #endregion

        #region Private methods

        private void ScheduleGetOrdersJob()
        {
            var jobDetails = JobBuilder.Create<GetOrdersJob>()
                                       .WithIdentity("GetOrdersJob")
                                       .Build();
            var trigger = TriggerBuilder.Create()
                                        .StartNow()
                                        .WithCronSchedule(CronHelper.GetCronExpression(ConfigurationHelper.GetValue<double>("GetOrdersInterval")))
                                        .Build();
            _scheduler.ScheduleJob(jobDetails, trigger);
        }

        private void ScheduleStockUpdateJob()
        {
            var jobDetails = JobBuilder.Create<StockUpdateJob>()
                                       .WithIdentity("StockUpdateJob")
                                       .Build();
            var trigger = TriggerBuilder.Create()
                                        .StartNow()
                                        .WithCronSchedule(CronHelper.GetCronExpression(ConfigurationHelper.GetValue<double>("StockUpdateInterval")))
                                        .Build();
            _scheduler.ScheduleJob(jobDetails, trigger);
        }

        private void ScheduleShipmentUpdateJob()
        {
            var jobDetails = JobBuilder.Create<ShipmentUpdateJob>()
                                       .WithIdentity("ShipmentUpdateJob")
                                       .Build();
            var trigger = TriggerBuilder.Create()
                                        .StartNow()
                                        .WithCronSchedule(CronHelper.GetCronExpression(ConfigurationHelper.GetValue<double>("ShipmentUpdateInterval")))
                                        .Build();
            _scheduler.ScheduleJob(jobDetails, trigger);
        }

        #endregion
    }
}

The jobs classes can then be created to do concrete specific work. I am giving an example of the GetOrdersJob

using System.Linq;
using Quartz;
using RakutenIntegrationService.Helpers;
using RakutenIntegrationService.Models.Response;
using RakutenIntegrationService.Services;

namespace RakutenIntegrationService.Jobs
{
    public class GetOrdersJob : IJob
    {
        #region Fields

        private readonly IRestService _restService;

        #endregion

        #region Constructors

        public GetOrdersJob(IRestService restService)
        {
            _restService = restService;
        }

        #endregion

        #region IJob members

        public void Execute(IJobExecutionContext context)
        {
            var uri = string.Concat(DataServiceConstants.BaseEndpointAddress, "order/list", RequestBuilder.ConstructListOrdersRequestParams());
            var response = _restService.Get<OrderResponse>(uri);
            if (response != null && response.Orders != null && response.Orders.Any())
            {
                var ordersToProcess = response.GetOrdersToProcess();
                if (ordersToProcess != null && ordersToProcess.Any())
                    OrderProcessor.ProcessOrders(ordersToProcess);
            }
        }

        #endregion
    }
}

And then define a Windows Service class that provides methods to Start and Stop the Scheduler

using System.ServiceProcess;
using Common.Logging;
using RakutenIntegrationService.Scheduler;

namespace RakutenIntegrationService
{
    public partial class RakutenService : ServiceBase
    {
        #region Fields

        private static ILog Log = LogManager.GetLogger<RakutenService>();
        private readonly ITaskScheduler _taskScheduler;

        #endregion

        public RakutenService(ITaskScheduler taskScheduler)
        {
            InitializeComponent();
            _taskScheduler = taskScheduler;
        }

        protected override void OnStart(string[] args)
        {
            Log.Info("Starting Rakuten Scheduler service.");
            _taskScheduler.Run();
        }

        protected override void OnStop()
        {
            Log.Info("Stopping Rakuten Scheduler service.");
            _taskScheduler.Stop();
        }
    }
}

And that’s pretty much about it. You can add as much custom functionality in the individual jobs classes depending what work you want the Scheduled Job to perform.