我正在制作一個java程序，它比較計算兩個給定數(shù)字之間的素數(shù)總數(shù)所需的時間。我必須計算順序以及線程需要多少時間。例如，我必須檢查順序計算需要多少時間：PrimeNumbers pn = new PrimeNumbers (1,1000);并將其與計算相同的事物但將其劃分為多個線程所需的時間進(jìn)行比較：PrimeThread p1 = new PrimeThread (1, 200);PrimeThread p2 = new PrimeThread (201, 400);PrimeThread p3 = new PrimeThread (401, 600);PrimeThread p4 = new PrimeThread (601, 800);PrimeThread p5 = new PrimeThread (801, 1000);我必須使用 System.currentTimeMillis() 來計算時間。線程應(yīng)該能夠更快地計算同樣的事情，但實(shí)際上更慢。到目前為止我有這個代碼：PrimeNumbers pn = new PrimeNumbers(1,1000);long startTimeSeq = System.currentTimeMillis();int totalNumbersSeq = pn.calculatePrimeNumbers();long finishTimeSeq = System.currentTimeMillis();float totalTimeSeq = finishTimeSeq - startTimeSeq;PrimeThread p1 = new PrimeThread (1, 200);PrimeThread p2 = new PrimeThread (201, 400);PrimeThread p3 = new PrimeThread (401, 600);PrimeThread p4 = new PrimeThread (601, 800);PrimeThread p5 = new PrimeThread (801, 1000);long startTimeThread = System.currentTimeMillis();p1.start();p2.start();p3.start();p4.start();p5.start();try {    p1.join();    p2.join();    p3.join();    p4.join();p5.join();} catch (InterruptedException e) {    e.printStackTrace();}long finishTimeThread = System.currentTimeMillis();float totalTimeThread = finishTimeThread - startTimeThread;int totalNumbersThread = p1.getNumPrimers() + p2.getNumPrimers() + p3.getNumPrimers() + p4.getNumPrimers() + p5.getNumPrimers();    System.out.println("Total prime numbers sequentially: " + numPrimers);System.out.println("Total time: " + totalTimeSeq);System.out.println("Total prime numbers with threads: " + resultatFinal);System.out.println("Total time: " + totalTimeThread); 打印的結(jié)果是：Total prime numbers sequentially: 169Total time: 1.0Total prime numbers with threads: 169Total time: 3.0如果我的內(nèi)容很混亂，我很抱歉，這是我第一次在這里發(fā)帖，而且我是編程新手。太感謝了。