【ANDROID STUDIO】 Set input and output data of a worker class WorkManager

 package com.example.wordmanager

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import androidx.lifecycle.Observer
import androidx.work.*
import kotlinx.android.synthetic.main.activity_main.*

class MainActivity : AppCompatActivity() {

    companion object {
        const val KEY_COUNT_VALUE = "key_count"
    }
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        button.setOnClickListener {
            setOneTimeWorkRequest()
        }

    }

    private fun setOneTimeWorkRequest() {
        val workManager = WorkManager.getInstance(applicationContext)
     val data: Data = Data.Builder()
         .putInt(KEY_COUNT_VALUE,125)
         .build()
        val constraints = Constraints.Builder()
            .setRequiresCharging(true)
            .build()
        val uploadRequest = OneTimeWorkRequest.Builder(UploadWorker::class.java)
            .setConstraints(constraints)
            .setInputData(data)
            .build()
        workManager.enqueue(uploadRequest)
        workManager.getWorkInfoByIdLiveData(uploadRequest.id)
            .observe(this, Observer {
                textView.text = it.state.name
                if(it.state.isFinished) {
                    val data = it.outputData
                    val message = data.getString(UploadWorker.KEY_WORKER)
                    Toast.makeText(applicationContext, message, Toast.LENGTH_LONG).show()
                }
            })
    }

}

package com.example.wordmanager

import android.content.Context
import android.util.Log
import androidx.work.Data
import androidx.work.Worker
import androidx.work.WorkerParameters
import java.text.SimpleDateFormat
import java.util.*

class UploadWorker(context: Context, params: WorkerParameters) : Worker(context,params) {
    companion object {
        const val KEY_WORKER = "key_worker"
    }
    override fun doWork(): Result {
        try {
            val count = inputData.getInt(MainActivity.KEY_COUNT_VALUE,0)
            for (i in 0 until count) {
                Log.i("MYTAG", "Uploading $i")
            }
            val time = SimpleDateFormat("dd/M/yyyy hh:mm:ss")
            val currentDate = time.format(Date())

            val outPutData = Data.Builder()
                .putString(KEY_WORKER,currentDate)
                .build()

            return Result.success(outPutData)
        } catch (e: Exception) {
            return Result.failure()
        }
    }
}