import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;
import java.util.concurrent.locks.ReentrantLock;

public class LockTest10050 {
public static void main(String[] args) {
final Bussiness bussiness = new Bussiness();

new Thread(new Runnable() {
public void run() {
for (int i = 1; i < 51; i++) {
bussiness.sub(i);
}
}
}).start();

new Thread(new Runnable() {
public void run() {
for (int i = 1; i < 51; i++) {
bussiness.main(i);
}
}
}).start();
}
}

class Bussiness {
Lock lock = new ReentrantLock();
Condition condition = lock.newCondition();
boolean flag = true;

public void sub(int i) {
lock.lock();
try {
while (!flag)
condition.await();
for (int j = 1; j < 11; j++) {
System.out.println("子线程第" + i + "次循环: 次数为" + j);
}
flag = false;
condition.signal();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}

public void main(int i) {
lock.lock();
try {
while (flag)
condition.await();
for (int j = 1; j < 101; j++) {
System.out.println("主线程第" + i + "次循环: 次数为" + j);
}
flag = true;
condition.signal();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}

}

API文档中实例代码：

class BoundedBuffer {
final Lock lock = new ReentrantLock();

   final Condition notFull  = lock.newCondition(); 

   final Condition notEmpty = lock.newCondition(); 

   final Object[] items = new Object[100];

   int putptr, takeptr, count;

   public void put(Object x) throws InterruptedException {
lock.lock();

     try {

       while (count == items.length)
notFull.await();

       items[putptr] = x;

       if (++putptr == items.length) putptr = 0;

       ++count;
notEmpty.signal();

     } finally {

       lock.unlock();

     }

   }

   public Object take() throws InterruptedException {
lock.lock();

     try {

       while (count == 0)
notEmpty.await();

       Object x = items[takeptr];

       if (++takeptr == items.length) takeptr = 0;

       --count;
notFull.signal();

       return x;
} finally {

       lock.unlock();

     }

   }

 }