PrimeNumbers.java

import java.util.ArrayList;
import java.util.List;

public class PrimeNumbers {

    private static class MultiThreadPrimeNumber implements Runnable {

        private int finish;
        private int start;

        public MultiThreadPrimeNumber(int start, int finish) {
            this.start = start;
            this.finish = finish;
        }

        private void getPrime() {
            List<Integer> prime = new ArrayList<>();
            for (int num = start; num <= finish; num ++) {
                boolean isPrime = true;
                for (int j = 2; j <= num/2; j++) {
                    if (num % j == 0) {
                        isPrime = false;
                        break;
                    }
                }
                if (isPrime) {
                    prime.add(num);
                }
            }
            System.out.println("\n Prime numbers in " + start + " - " + finish + " region are "+ prime);
        }
        
        @Override
        public void run() {
            System.out.println("Thread is executing " + Thread.currentThread().getName());
            getPrime();
        }
    }
    
    public static void main(String[] args) {
        int start = 1;
        int finish = 10;
        List<Thread> threads = new ArrayList<>();
        for (int i = 1; i <= 10; i++ ) {
            String threadName = i + "th thread";
            Thread thread = new Thread(new MultiThreadPrimeNumber(start, finish), threadName);
            threads.add(thread);
            start += 10;
            finish += 10;
        }
        for (Thread thread : threads) { thread.start(); }
    }
}