【ANDROID STUDIO】Periodic Work Request Work Manager

 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.*
import java.util.concurrent.TimeUnit

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()
            setPeriodicWorkRequest()
        }

    }

    private fun setPeriodicWorkRequest() {
        val periodicWorkRequest = PeriodicWorkRequest.Builder(DownloadingWorker::class.java,16,
            TimeUnit.MINUTES)
            .build()
        WorkManager.getInstance(applicationContext).enqueue(periodicWorkRequest)
    }

    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()
        val filteringRequest = OneTimeWorkRequest.Builder(FilteringWorker::class.java)
            .build()
        val compressingRequest= OneTimeWorkRequest.Builder(CompressingWorker::class.java)
            .build()
        val downloadingWorker= OneTimeWorkRequest.Builder(DownloadingWorker::class.java)
            .build()
        val paralleWorks = mutableListOf<OneTimeWorkRequest>()
        paralleWorks.add(downloadingWorker)
        paralleWorks.add(filteringRequest)
       workManager
           .beginWith(paralleWorks)
           .then(compressingRequest)
           .then(uploadRequest)
           .enqueue()
        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 androidx.work.Worker
import androidx.work.WorkerParameters
import android.util.Log
import java.text.SimpleDateFormat
import java.util.*

class DownloadingWorker(context: Context, params: WorkerParameters) : Worker(context,params) {


    override fun doWork(): Result {
        try {

            for (i in 0..300) {
                Log.i("MYTAG", "Downloading $i")
            }

            val time = SimpleDateFormat("dd/M/yyyy hh:mm:ss")
            val currentDate = time.format(Date())
            Log.i("MYTAG","Completed $currentDate")

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

}