add detail desc.

README.md

@@ -5,8 +5,17 @@
 [![Build status](https://ci.appveyor.com/api/projects/status/i02yxvu0mvhyv5nk?svg=true)](https://ci.appveyor.com/project/icsharp/hangfire-recurringjobextensions)
 [![License MIT](https://img.shields.io/badge/license-MIT-green.svg)](http://opensource.org/licenses/MIT)
 
-This repo is the extension for [Hangfire](https://github.com/HangfireIO/Hangfire) to build `RecurringJob` automatically. We can use the attribute `RecurringJobAttribute` to assign the interface/instance/static method.
+This repo is the extension for [Hangfire](https://github.com/HangfireIO/Hangfire) to build `RecurringJob` automatically.
 When app start, `RecurringJob` will be added/updated automatically.
+There is two ways to build `RecurringJob`.
+
+- `RecurringJobAttribute` attribute
+- Json Configuration
+
+## Using RecurringJobAttribute
+
+We can use the attribute `RecurringJobAttribute` to assign the interface/instance/static method.
+
 
 ```csharp
 public class RecurringJobService
@@ -29,4 +38,107 @@ public class RecurringJobService
 }
 ```
 
-More details [here](https://github.com/icsharp/Hangfire.Topshelf).
+## Json Configuration
+
+It is similar to [quartz.net](http://www.quartz-scheduler.net/), We also define the unified interface `IRecurringJob`.
+Recurring jobs must impl the specified interface like this.
+
+```csharp
+[AutomaticRetry(Attempts = 0)]
+[DisableConcurrentExecution(90)]
+public class LongRunningJob : IRecurringJob
+{
+    public void Execute(PerformContext context)
+    {
+        context.WriteLine($"{DateTime.Now.ToString("yyyy/MM/dd HH:mm:ss")} LongRunningJob Running ...");
+
+        var runningTimes = context.GetJobData<int>("RunningTimes");
+
+        context.WriteLine($"get job data parameter-> RunningTimes: {runningTimes}");
+
+        var progressBar = context.WriteProgressBar();
+
+        foreach (var i in Enumerable.Range(1, runningTimes).ToList().WithProgress(progressBar))
+        {
+            Thread.Sleep(1000);
+        }
+    }
+}
+```
+
+Now we need to provider the json config file to assign the implemented recurring job, the json configuration samples as below.
+
+```json
+[{
+    "job-name": "My Job1",
+    "job-type": "Hangfire.Samples.MyJob1, Hangfire.Samples",
+    "cron-expression": "*/1 * * * *",
+    "timezone": "China Standard Time",
+    "queue": "jobs"
+},
+{
+    "job-name": "My Job2",
+    "job-type": "Hangfire.Samples.MyJob2, Hangfire.Samples",
+    "cron-expression": "*/5 * * * *",
+    "job-data": {
+        "IntVal": 1,
+        "StringVal": "abcdef",
+        "BooleanVal": true,
+        "SimpleObject": {
+            "Name": "Foo",
+            "Age": 100
+        }
+    }
+},
+{
+    "job-name": "Long Running Job",
+    "job-type": "Hangfire.Samples.LongRunningJob, Hangfire.Samples",
+    "cron-expression": "*/2 * * * *",
+    "job-data": {
+        "RunningTimes": 300
+    }
+}]
+```
+
+The json token description to the configuration is here.
+
+JSON Token | Description
+---|---
+**job-name** | *[required]* The job name to `RecurringJob`.
+**job-type** | *[required]* The job type while impl the interface `IRecurringJob`.
+**cron-expression** | *[required]* Cron expressions.
+timezone | *[optional]* Default value is `TimeZoneInfo.Local`.
+queue | *[optional]* The specified queue name , default value is `default`.
+job-data | *[optional]* Likely to the [quartz.net](http://www.quartz-scheduler.net/) `JobDataMap`, it is can be deserialized to the type `Dictionary<string,object>`.
+enable | *[optional]* Whether the `RecurringJob` can be added/updated, default value is true, if false `RecurringJob` will be deleted automatically.
+
+*To the json token `job-data`, we can use extension method to get data with specified key from `PerformContext` when recurring job running.*
+
+```csharp
+var runningTimes = context.GetJobData<int>("RunningTimes");
+```
+
+## Building RecurringJob
+
+Finally, we can use extension method `UseRecurringJob` to build `RecurringJob`. In .NET Core's Startup.cs.
+
+``` csharp
+public void ConfigureServices(IServiceCollection services)
+{
+    services.AddHangfire(x =>
+    {
+        x.UseSqlServerStorage(_config.GetConnectionString("Hangfire"));
+
+        x.UseConsole();
+
+        //using json config file to build RecurringJob automatically.
+        x.UseRecurringJob("recurringjob.json");
+        //using RecurringJobAttribute to build RecurringJob automatically.
+        x.UseRecurringJob(typeof(RecurringJobService));
+
+        x.UseDefaultActivator();
+    });
+}
+```
+
+*For the json configuration file, we can monitor the file change and reload `RecurringJob` dynamically by passing the parameter `reloadOnChange = true`.*