import java.util.ArrayList;

import java.util.List;

import java.util.concurrent.BlockingQueue;

import java.util.concurrent.LinkedBlockingDeque;

public class ThreadPool {

private BlockingQueue<Task> taskBlockingQueue;

private List<WorkerThread> workerThreadList;

private final int numberOfThreads;

public ThreadPool(int numberOfThreads) {

this.numberOfThreads = numberOfThreads;

taskBlockingQueue = new LinkedBlockingDeque<>();

workerThreadList = new ArrayList<>(numberOfThreads);

for (int i = 0; i < numberOfThreads; i++) {

WorkerThread workerThread = new WorkerThread();

workerThreadList.add(workerThread);

workerThread.start();

}

}

public void execute(Task task) {

synchronized (taskBlockingQueue) {

taskBlockingQueue.add(task);

taskBlockingQueue.notify();

}

}

public class WorkerThread extends Thread {

@Override

public void run() {

super.run();

Runnable task;

while (true) {

synchronized (taskBlockingQueue) {

while (taskBlockingQueue.isEmpty()) {

try {

taskBlockingQueue.wait();

} catch (InterruptedException e) {

System.out.println("An error occurred while queue is waiting: " + e.getMessage());

e.printStackTrace();

}

}

task = taskBlockingQueue.poll();

try {

task.run();

} catch (RuntimeException e) {

System.out.println("This thread pool is interrupted due to an issue: " + e.getMessage());

e.printStackTrace();

}

}

}

}

}

}