Java 使用pipe進行線程間通訊

Thinking in Java 中的例子，兩個線程Sender&Receiver使用pipe進行通訊。Pipe是一個阻塞隊列，解決了“生產者-消費者”線程通訊的問題。

import java.io.IOException;
import java.io.PipedReader;
import java.io.PipedWriter;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;

class Sender implements Runnable
{
    PipedWriter pipedWriter=new PipedWriter();
    @Override public void run() {
        try {
            for (char a = 'a'; a <= 'z'; a++) {
                Thread.sleep(500);
                pipedWriter.write(a);
                //block
            }
        } catch (InterruptedException e) {
            e.printStackTrace();
        } catch (IOException e)
        {
            System.out.println("Close Pipe");
        }
    }
    PipedWriter getPipedWriter()
    {
        return pipedWriter;
    }
}
class Reciever implements Runnable
{
    PipedReader pipedReader=null;
    @Override public void run()
    {
        try{
            while (true)
            {
                char a=(char)pipedReader.read();
                System.out.print(a+", ");
                //block while nothing in the pipe
            }
        }catch (IOException e)
        {
            System.out.println("Close Pipe");
        }
    }
    public Reciever(Sender sender) throws IOException
    {//獲得pipe
        pipedReader=new PipedReader(sender.getPipedWriter());
    }
}
public class Main{
    public static void main(String[]args)
    {
        try {
            Sender sender = new Sender();
            Reciever reciever = new Reciever(sender);
            ExecutorService service= Executors.newCachedThreadPool();
            service.execute(sender);
            service.execute(reciever);
            Thread.sleep(20000);//跑一會
            service.shutdown();//關閉
            System.out.println("Over!");
        }catch (IOException e)
        {
            e.printStackTrace();
        }catch (InterruptedException e)
        {
            e.printStackTrace();
        }

    }