任务间使用管道进行输入输出

来源：互联网发布：js初学者编辑：程序博客网时间：2024/06/14 03:00

内容：通过输入/输出在线程间进行通信通常很有用。利用PipedWriter类（允许任务向管道写）和PipedReader类（允许不同任务从同一个管道中读取）。下面代码中Sender和Receiver代表了需要相互通信的两个任务。Sender把数据放进Writer，然后休眠一段时间。然而，Receiver没有sleep（）和wait（）。但当他调用read（）时，如果没有更多的数据，管道将阻塞，而普通I/O是不能打断的。

class Sender implements Runnable {private Random rand = new Random(47);private PipedWriter out = new PipedWriter();public PipedWriter getPipedWriter() {return out;}@Overridepublic void run() {try {while (true) {for (char c = 'A'; c <= 'z'; c++) {out.write(c);TimeUnit.MILLISECONDS.sleep(rand.nextInt(500));}}} catch (IOException e) {System.out.println(e + " Sender write exception");} catch (InterruptedException e) {System.out.println(e + "Sender sleeo interrupted");}}}class Receiver implements Runnable {private PipedReader in;public Receiver(Sender sender) throws IOException {in = new PipedReader(sender.getPipedWriter());}@Overridepublic void run() {try {while (true) {System.out.println("Read: " + (char)in.read() + ". ");}} catch (IOException e) {System.out.println(e + " Receiver read exception");}}}public class PipedIO {public static void main(String[] args) throws Exception {Sender sender = new Sender();Receiver receiver = new Receiver(sender);ExecutorService exec = Executors.newCachedThreadPool();exec.execute(sender);exec.execute(receiver);TimeUnit.SECONDS.sleep(4);exec.shutdownNow();}}

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