面试题：要求用线程顺序打印A1B2C3....Z26
1 用synchronized+wait()+notify()实现
public class T_Sync_wait_notify {
public static void main(String[] args) {
final Object o = new Object();
char[] aI = "1234567".toCharArray();
char[] aC = "ABCDEFG".toCharArray();
new Thread(() -> {
synchronized (o) {
for (char c : aI) {
System.out.print(c);
try {
o.notify();
o.wait(); //让出锁
} catch (InterruptedException e) {
e.printStackTrace();
}
}
o.notify(); //必须，否则无法停止程序
}
},"t1").start();
new Thread(()->{
synchronized (o){
for (char c:aC){
System.out.print(c);
try {
o.notify();
o.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
o.notify();
}
},"t2").start();
}
}
2 用LockSupport的park()和unPark()实现
public class T_LockSupport {
static Thread t1 = null, t2 = null;
public static void main(String[] args) {
char[] aI = "1234567".toCharArray();
char[] aC = "ABCDEFG".toCharArray();
t1 = new Thread(() -> {
for (char c : aI) {
System.out.print(c);
LockSupport.unpark(t2); //叫醒T2
LockSupport.park();//T1阻塞
}
}, "t1");
t2 = new Thread(() -> {
for (char c : aC) {
LockSupport.park(); //t2阻塞
System.out.print(c);
LockSupport.unpark(t1);//叫醒t1
}
});
t1.start();
t2.start();
}
}
3 ReentrantLock+1个Condition实现
public class T_Lock_Condition {
public static void main(String[] args) {
char[] aI = "1234567".toCharArray();
char[] aC = "ABCDEFG".toCharArray();
Lock lock = new ReentrantLock();
Condition condition = lock.newCondition();
new Thread(() -> {
try {
lock.lock();
for (char c : aI) {
System.out.print(c);
condition.signal();
condition.await();
}
condition.signal();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}, "t1").start();
new Thread(() -> {
try {
lock.lock();
for (char c : aC) {
System.out.print(c);
condition.signal();
condition.await();
}
} catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}, "t2").start();
}
}
4 ReentrantLock+2个Condition实现
public class T_Lock_Condition2 {
public static void main(String[] args) {
char[] aI = "1234567".toCharArray();
char[] aC = "ABCDEFG".toCharArray();
Lock lock = new ReentrantLock();
Condition condition1 = lock.newCondition();
Condition condition2 = lock.newCondition();
new Thread(() -> {
try {
lock.lock();
for (char c : aI) {
System.out.print(c);
condition2.signal();
condition1.await();
}
condition2.signal();
} catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}, "t1").start();
new Thread(() -> {
try {
lock.lock();
for (char c : aC) {
System.out.print(c);
condition1.signal();
condition2.await();
}
condition1.signal();
} catch (Exception e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}).start();
}
}
5 AtomicInteger实现
public class T_AtomicInteger {
static AtomicInteger threadNo = new AtomicInteger(1);
public static void main(String[] args) {
char[] aI = "1234567".toCharArray();
char[] aC = "ABCDEFG".toCharArray();
new Thread(() -> {
for (char c : aI) {
while (threadNo.get() != 1) {
}
System.out.print(c);
threadNo.set(2);
}
}, "t1").start();
new Thread(() -> {
for (char c : aC) {
while (threadNo.get() != 2) {
}
System.out.print(c);
threadNo.set(1);
}
}).start();
}
}
6 ArrayBlockingQueue实现
public class T_BlockingQueue {
static BlockingQueue
static BlockingQueue
public static void main(String[] args) {
char[] aI = "1234567".toCharArray();
char[] aC = "ABCDEFG".toCharArray();
new Thread(() -> {
for (char c : aI) {
System.out.print(c);
try {
q1.put("ok");
q2.take();
} catch (Exception e) {
e.printStackTrace();
}
}
}, "t1").start();
new Thread(() -> {
for (char c : aC) {
try {
q1.take();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.print(c);
try {
q2.put("ok");
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "t2").start();
}
}
7 用LinkedTransferQueue实现
public class T_TransferQueue {
public static void main(String[] args) {
char[] aI = "1234567".toCharArray();
char[] aC = "ABCDEFG".toCharArray();
TransferQueue
new Thread(() -> {
for (char c : aI) {
try {
System.out.print(queue.take());
queue.transfer(c);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
},"t1").start();
new Thread(()->{
for (char c:aC){
try {
queue.transfer(c);
System.out.print(queue.take());
} catch (InterruptedException e) {
e.printStackTrace();
}
}
},"t2").start();
}
}
实现方法有很多种，这里就不一一列举了......