ThreadExample.kt

fun main() {
   val les = Executors.newFixedThreadPool(5)
    for (i in 0..9) {
        val worker: Runnable = WorkerThread("" + i)
        les.execute(worker)
    }
    les.shutdown()
    while (!les.isTerminated) { }
    println("Finished all threads")
}

class WorkerThread(
    private val command: String
) : Runnable {
    override fun run() {
        println(Thread.currentThread().name + " Start. Command = " + command)
        processCommand()
        println(Thread.currentThread().name + " End.")
    }

    private fun processCommand() {
        try {
            Thread.sleep(5000)
        } catch (e: InterruptedException) {
            e.printStackTrace()
        }
    }

    override fun toString(): String {
        return command
    }
}

// Log
/**
* pool-4-thread-1 Start. Command = 0
* pool-4-thread-4 Start. Command = 3
* pool-4-thread-3 Start. Command = 2
* pool-4-thread-2 Start. Command = 1
* pool-4-thread-5 Start. Command = 4
* pool-4-thread-1 End.
* pool-4-thread-3 End.
* pool-4-thread-3 Start. Command = 6. // this command process is waiting until pool-4-thread-3 is completed.
* pool-4-thread-4 End.
* pool-4-thread-5 End.
* pool-4-thread-1 Start. Command = 5
* pool-4-thread-2 End.
* pool-4-thread-5 Start. Command = 8
* pool-4-thread-4 Start. Command = 7
* pool-4-thread-2 Start. Command = 9
* pool-4-thread-5 End.
* pool-4-thread-2 End.
* pool-4-thread-4 End.
* pool-4-thread-3 End.
* pool-4-thread-1 End.
* Finished all threads
*/