Java 多线程打印的12种实现方法
下面我将为你详细介绍12种不同的Java多线程打印实现方法:
- synchronized + wait/notify 方法
java
public class Method1_Synchronized {
private static final Object lock = new Object();
private static int number = 1;
private static final int MAX = 10;
public static void main(String[] args) {
new Thread(() -> {
synchronized (lock) {
while (number <= MAX) {
if (number % 2 == 1) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
lock.notify();
} else {
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
lock.notify();
}
}, "Thread-A").start();
new Thread(() -> {
synchronized (lock) {
while (number <= MAX) {
if (number % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
lock.notify();
} else {
try {
lock.wait();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
}, "Thread-B").start();
}
}
- ReentrantLock + Condition 方法
java
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
public class Method2_ReentrantLock {
private static final ReentrantLock lock = new ReentrantLock();
private static final Condition condition = lock.newCondition();
private static int number = 1;
private static final int MAX = 10;
public static void main(String[] args) {
new Thread(() -> {
while (number <= MAX) {
lock.lock();
try {
if (number % 2 == 1) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
condition.signal();
} else {
condition.await();
}
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
}, "Thread-A").start();
new Thread(() -> {
while (number <= MAX) {
lock.lock();
try {
if (number % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
condition.signal();
} else {
condition.await();
}
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
lock.unlock();
}
}
}, "Thread-B").start();
}
}
- Semaphore 信号量方法
java
import java.util.concurrent.Semaphore;
public class Method3_Semaphore {
private static Semaphore semaphoreA = new Semaphore(1);
private static Semaphore semaphoreB = new Semaphore(0);
private static int number = 1;
private static final int MAX = 10;
public static void main(String[] args) {
new Thread(() -> {
while (number <= MAX) {
try {
semaphoreA.acquire();
if (number <= MAX) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
semaphoreB.release();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "Thread-A").start();
new Thread(() -> {
while (number <= MAX) {
try {
semaphoreB.acquire();
if (number <= MAX) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
semaphoreA.release();
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "Thread-B").start();
}
}
- LockSupport 方法
java
import java.util.concurrent.locks.LockSupport;
public class Method4_LockSupport {
private static int number = 1;
private static final int MAX = 10;
private static Thread threadA, threadB;
public static void main(String[] args) {
threadA = new Thread(() -> {
while (number <= MAX) {
if (number % 2 == 1) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
LockSupport.unpark(threadB);
} else {
LockSupport.park();
}
}
}, "Thread-A");
threadB = new Thread(() -> {
while (number <= MAX) {
if (number % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
LockSupport.unpark(threadA);
} else {
LockSupport.park();
}
}
}, "Thread-B");
threadA.start();
threadB.start();
}
}
- CyclicBarrier 方法
java
import java.util.concurrent.BrokenBarrierException;
import java.util.concurrent.CyclicBarrier;
public class Method5_CyclicBarrier {
private static final int THREAD_COUNT = 2;
private static CyclicBarrier barrier = new CyclicBarrier(THREAD_COUNT);
private static int number = 1;
private static final int MAX = 10;
public static void main(String[] args) {
new Thread(() -> {
while (number <= MAX) {
try {
if (number % 2 == 1) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
barrier.await();
} catch (InterruptedException | BrokenBarrierException e) {
e.printStackTrace();
}
}
}, "Thread-A").start();
new Thread(() -> {
while (number <= MAX) {
try {
if (number % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
barrier.await();
} catch (InterruptedException | BrokenBarrierException e) {
e.printStackTrace();
}
}
}, "Thread-B").start();
}
}
- CountDownLatch 方法
java
import java.util.concurrent.CountDownLatch;
public class Method6_CountDownLatch {
private static int number = 1;
private static final int MAX = 10;
public static void main(String[] args) throws InterruptedException {
for (int i = 0; i < MAX; i++) {
CountDownLatch latch = new CountDownLatch(1);
CountDownLatch nextLatch = new CountDownLatch(1);
new Thread(() -> {
try {
latch.await();
if (number <= MAX) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
nextLatch.countDown();
} catch (InterruptedException e) {
e.printStackTrace();
}
}, "Thread-" + (i + 1)).start();
latch.countDown();
nextLatch.await();
}
}
}
- BlockingQueue 方法
java
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
public class Method7_BlockingQueue {
private static BlockingQueue<Integer> queueA = new ArrayBlockingQueue<>(1);
private static BlockingQueue<Integer> queueB = new ArrayBlockingQueue<>(1);
private static int number = 1;
private static final int MAX = 10;
static {
try {
queueA.put(0); // 初始化信号
} catch (InterruptedException e) {
e.printStackTrace();
}
}
public static void main(String[] args) {
new Thread(() -> {
while (number <= MAX) {
try {
queueA.take();
if (number <= MAX) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
queueB.put(0);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "Thread-A").start();
new Thread(() -> {
while (number <= MAX) {
try {
queueB.take();
if (number <= MAX) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
queueA.put(0);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "Thread-B").start();
}
}
- Phaser 方法
java
import java.util.concurrent.Phaser;
public class Method8_Phaser {
private static int number = 1;
private static final int MAX = 10;
public static void main(String[] args) {
Phaser phaser = new Phaser(2);
new Thread(() -> {
while (number <= MAX) {
if (number % 2 == 1) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
phaser.arriveAndAwaitAdvance();
}
}, "Thread-A").start();
new Thread(() -> {
while (number <= MAX) {
if (number % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
phaser.arriveAndAwaitAdvance();
}
}, "Thread-B").start();
}
}
- Exchanger 方法
java
import java.util.concurrent.Exchanger;
public class Method9_Exchanger {
private static int number = 1;
private static final int MAX = 10;
public static void main(String[] args) {
Exchanger<Boolean> exchanger = new Exchanger<>();
new Thread(() -> {
boolean flag = true;
while (number <= MAX) {
try {
if (number % 2 == 1) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
flag = exchanger.exchange(flag);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "Thread-A").start();
new Thread(() -> {
boolean flag = false;
while (number <= MAX) {
try {
if (number % 2 == 0) {
System.out.println(Thread.currentThread().getName() + ": " + number++);
}
flag = exchanger.exchange(flag);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}, "Thread-B").start();
}
}
- CompletableFuture 方法
java
import java.util.concurrent.CompletableFuture;
public class Method10_CompletableFuture {
private static int number = 1;
private static final int MAX = 10;
public static void main(String[] args) {
CompletableFuture<Void> future = CompletableFuture.completedFuture(null);
for (int i = 1; i <= MAX; i++) {
final int current = i;
future = future.thenRunAsync(() -> {
System.out.println(Thread.currentThread().getName() + ": " + current);
});
}
future.join();
}
}
- 线程池 + Future 方法
java
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
public class Method11_ThreadPool {
private static final int MAX = 10;
public static void main(String[] args) throws Exception {
ExecutorService executor = Executors.newFixedThreadPool(2);
Future<?> future1 = executor.submit(() -> {
for (int i = 1; i <= MAX; i += 2) {
System.out.println(Thread.currentThread().getName() + ": " + i);
}
});
Future<?> future2 = executor.submit(() -> {
for (int i = 2; i <= MAX; i += 2) {
System.out.println(Thread.currentThread().getName() + ": " + i);
}
});
future1.get();
future2.get();
executor.shutdown();
}
}
- AtomicInteger + 自旋锁方法
java
import java.util.concurrent.atomic.AtomicInteger;
public class Method12_AtomicInteger {
private static AtomicInteger number = new AtomicInteger(1);
private static final int MAX = 10;
private static volatile int turn = 1; // 1: Thread-A, 2: Thread-B
public static void main(String[] args) {
new Thread(() -> {
while (number.get() <= MAX) {
if (turn == 1 && number.get() <= MAX) {
System.out.println(Thread.currentThread().getName() + ": " + number.getAndIncrement());
turn = 2;
}
}
}, "Thread-A").start();
new Thread(() -> {
while (number.get() <= MAX) {
if (turn == 2 && number.get() <= MAX) {
System.out.println(Thread.currentThread().getName() + ": " + number.getAndIncrement());
turn = 1;
}
}
}, "Thread-B").start();
}
}
方法特点对比
方法 优点 缺点 适用场景
synchronized 简单易用,JVM内置 性能相对较低 简单的同步需求
ReentrantLock 功能丰富,性能好 需要手动释放锁 复杂的同步需求
Semaphore 灵活的许可控制 可能产生死锁 资源池、限流
LockSupport 精确控制线程 需要管理park/unpark 需要精细控制线程
CyclicBarrier 可重复使用 需要固定线程数 多阶段任务
CountDownLatch 一次性同步 不可重复使用 主线程等待子线程
BlockingQueue 解耦生产消费 需要管理队列 生产者消费者模式
Phaser 灵活的阶段控制 相对复杂 多阶段复杂任务
Exchanger 线程间数据交换 只能两个线程 配对线程数据交换
CompletableFuture 函数式编程 链式调用复杂 异步编程
线程池 资源管理 需要关闭线程池 任务执行管理
AtomicInteger 无锁操作 自旋消耗CPU 简单的原子操作
这些方法涵盖了Java并发编程的主要工具类,你可以根据具体需求选择合适的方法。