public class PrimeFinder implements Runnable {
    Thread go;
    StringBuffer primes = new StringBuffer();
    int time = 0;

    public PrimeFinder() {
        start();
        while (primes != null) {
            System.out.println(time);
            try {
                Thread.sleep(1000);
            } catch(InterruptedException exc) {
                // do nothing
            }
            time++;
        }
    }

    public void start() {
        if (go == null) {
            go = new Thread(this);
            go.start();
        }
    }

    public void run() {
        int quantity = 1_000_000;
        int numPrimes = 0;
        // candidate: the number that might be prime
        int candidate = 2;
        primes.append("\nFirst ").append(quantity).append(" primes:\n\n");
        while (numPrimes < quantity) {
            if (isPrime(candidate)) {
                primes.append(candidate).append(" ");
                numPrimes++;
            }
            candidate++;
        }
        System.out.println(primes);
        primes = null;
        System.out.println("\nTime elapsed: " + time + " seconds");
    }

    public static boolean isPrime(int checkNumber) {
        double root = Math.sqrt(checkNumber);
        for (int i = 2; i <= root; i++) {
            if (checkNumber % i == 0) {
                return false;
            }
        }
        return true;
    }

    public static void main(String[] arguments) {
        new PrimeFinder();
    }
}

正如标题所说，我没有在控制台中得到程序的最终结果。。。计时器会一直计数，直到计算完成，但是当程序应该打印出结果时，控制台会清除并变为空白。我试着在某种在线编译器中输入代码，果然，最终结果打印出来了。有没有人遇到过类似的问题？如果有，你是如何解决的？提前谢谢！