java线程面试题1

    子线程循环10次，接着主线程循环100，接着又回到子线程循环10次，接着再回到主线程又循环100，如此循环50次，请写出程序。

 

备注：不可能一上来就写出上面的完整代码，最初写出来的代码如下，问题在于两个线程的代码要参照同一个变量，即这两个线程的代码要共享数据，所以，把这两个线程的执行代码搬到同一个类中去：

 

public class InterviewQuestionTest {

  public static void main(String[] args) {  new InterviewQuestionTest().init(); }

 private void init() {  final Business business = new Business();  new Thread() {   public void run() {    for (int i = 1; i <= 50; i++) {     business.sub(i);    }   }  }.start();  for (int i = 1; i <= 50; i++) {   business.main(i);  } }

 class Business {  private boolean bShouldRun = true;

  public synchronized void sub(int count) {   if (!bShouldRun) {    try {     this.wait();    } catch (InterruptedException e) {     e.printStackTrace();    }   }   for (int j = 1; j <= 10; j++) {

    System.out.println(Thread.currentThread().getName() + "i:"      + count + " sub j:" + j);   }   bShouldRun = false;   this.notify();  }

  public synchronized void main(int count) {   if (bShouldRun) {    try {     this.wait();    } catch (InterruptedException e) {     e.printStackTrace();    }   }

   for (int j = 1; j <= 100; j++) {

    System.out.println(Thread.currentThread().getName() + "i:"      + count + " main j:" + j);   }   bShouldRun = true;   this.notify();  } }

}