public class OneByOne {
private Lock lock = new ReentrantLock();
private Condition conditionA = lock.newCondition();
private Condition conditionB = lock.newCondition();
private Condition conditionC = lock.newCondition();
private String firstChar = "A";
private int count = 3;
class A implements Runnable{
public void run(){
try{
lock.lock();
for(int i = 0 ; i < count; i++){
while(!Thread.currentThread().getName().equals(firstChar)){
conditionA.await();
}
System.out.println("A");
firstChar = "B";
conditionB.signal();
}
}catch(Exception e){
e.printStackTrace();
}finally{
lock.unlock();
}
}
}
class B implements Runnable{
public void run(){
try{
lock.lock();
for(int i = 0 ; i < count; i++){
while(!Thread.currentThread().getName().equals(firstChar)){
conditionB.await();
}
System.out.println("B");
firstChar = "A";
conditionA.signal();
}
}catch(Exception e){
e.printStackTrace();
}finally{
lock.unlock();
}
}
}
public static void main(String[] args){
OneByOne obo = new OneByOne();
Thread a = new Thread(obo.new A());
Thread b = new Thread(obo.new B());
a.setName("A");
b.setName("B");
a.start();
b.start();
}
}
