Overview

HttpJob is a built-in HTTP request scheduled task in UniCon, implemented using IHttpClientFactory and supporting all standard HTTP methods including GET, POST, PUT, and DELETE. It allows configuration of request headers, query parameters, and request body, making it ideal for sending data or heartbeat packets to cloud platform Webhooks or RESTful APIs periodically.

The job execution results are recorded in the logging system without throwing exceptions (gracefully degrading to logs on error), ensuring the stability of the scheduler.

Usage

Register the task through JobScheduler.ScheduleJobAsync<HttpJob>() and pass parameters using the JobDataMap:

await jobScheduler.ScheduleJobAsync<HttpJob>(
    jobId: "PushDataToCloud",
    cronExpression: "0 0/5 * * * ?",
    data: new JobDataMap
    {
        [JobDataKeys.HttpUrl]    = "https://api.example.com/v1/data",
        [JobDataKeys.HttpMethod] = "POST",
        [JobDataKeys.HttpBody]   = "{\"deviceId\": \"PLC_01\", \"status\": \"running\"}",
        [JobDataKeys.HttpHeaders]= "{\"Authorization\": \"Bearer token123\", \"Content-Type\": \"application/json\"}"
    }
);

Parameters

Pass the following key-value pairs through JobDataMap (recommended to use the JobDataKeys constant class to avoid spelling errors):

JobDataKeys Constant	Actual Key Name	Type	Description	Required	Default Value
JobDataKeys.HttpUrl	Job_Http_Url	string	Target URL	Yes	—
JobDataKeys.HttpMethod	Job_Http_Method	string	HTTP Request Method (GET, POST, PUT, DELETE, etc.)	No	"GET"
JobDataKeys.HttpHeaders	Job_Http_Headers	string	JSON-serialized request headers dictionary Dictionary<string, string>	No	None
JobDataKeys.HttpQueryParams	Job_Http_QueryParams	string	JSON-serialized query parameters dictionary Dictionary<string, string>	No	None
JobDataKeys.HttpBody	Job_Http_Body	string	Request body string (always sent with application/json encoding)	No	None

Returns

HttpJob executes asynchronously and has no direct return value. Execution results are logged through the logging system:

Condition	Log Level	Content
Execution Start	Information	Executing HttpJob: {Method} {Url}
Execution Success	Information	HttpJob response: {StatusCode}
URL Empty	Warning	HttpJob skipped: URL is null or empty.
Execution Failure	Error	HttpJob request failed. {Exception}
Query Parameters Parse Failure	Error	Failed to parse HttpJob query parameters. {Exception}
Request Headers Parse Failure	Error	Failed to apply HttpJob headers. {Exception}

Examples

Example 1: POST data to cloud Webhook every 5 minutes

await jobScheduler.ScheduleJobAsync<HttpJob>(
    jobId: "PushDataToCloud",
    cronExpression: "0 0/5 * * * ?",  // Every 5 minutes
    data: new JobDataMap
    {
        [JobDataKeys.HttpUrl]     = "https://api.example.com/v1/data",
        [JobDataKeys.HttpMethod]  = "POST",
        [JobDataKeys.HttpBody]    = "{\"deviceId\": \"PLC_01\", \"status\": \"running\"}",
        [JobDataKeys.HttpHeaders] = "{\"Authorization\": \"Bearer token123\"}"
    }
);

Example 2: Scheduled GET request with query parameters

await jobScheduler.ScheduleJobAsync<HttpJob>(
    jobId: "QueryCloudConfig",
    cronExpression: "0 0 * * * ?",  // Hourly
    data: new JobDataMap
    {
        [JobDataKeys.HttpUrl]         = "https://config.example.com/api/settings",
        [JobDataKeys.HttpMethod]      = "GET",
        [JobDataKeys.HttpQueryParams] = "{\"gatewayId\": \"GW_01\", \"version\": \"2\"}"
    }
);

Example 3: Heartbeat detection GET request every 5 minutes

await jobScheduler.ScheduleJobAsync<HttpJob>(
    jobId: "Heartbeat",
    cronExpression: "0 0/5 * * * ?",
    data: new JobDataMap
    {
        [JobDataKeys.HttpUrl]    = "https://api.example.com/heartbeat",
        [JobDataKeys.HttpMethod] = "GET"
    }
);

Contributors: Entity-now