线程间的协作（3）——管道输入/输出流

1.管道输入/输出流类

    分为两类，字节流管道类（PipedInputStream/PipedOutputStream）和字符流管道类（PipedReader/ PipedWriter）。这两个IO流实现了可以在不同的任务中对同一个管道进行读写操作，这个模型可以看成是“生产者消-费者模式”的变体，管道是一个阻塞队列。

import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;
import java.io.PipedReader;
import java.io.PipedWriter;
import java.util.Scanner;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;

public class PipeIO {
	public static void main(String[] args) {
		ReadPipe read=new ReadPipe();
		WritePipe write=new WritePipe();
		ExecutorService exec=Executors.newCachedThreadPool();
		try {
			write.getWriter().connect(read.getRead());;//必须将两个管道进行连接，然后才可进行线程间的数据交互
			exec.execute(read);
			exec.execute(write);
		} catch (IOException e) {
			// TODO Auto-generated catch block
			e.printStackTrace();
		}
	}
}
class ReadPipe implements Runnable{
	PipedReader read=new PipedReader();
	public PipedReader getRead(){
		return  read;
	}
	@Override
	public void run() {
		try {
			while(true){
				System.out.println("read:"+(char)read.read()+";");//当前线程从管道读取数据
			}	
		} catch (IOException e) {
			// TODO: handle exception
		}
	}
}
class WritePipe implements Runnable{
	PipedWriter writer=new PipedWriter();
	public PipedWriter getWriter(){
		return  writer;
	}
	@Override
	public void run() {
		try {
			while(true){
				for(char a='A';a<='z';a++){
					writer.write(a);//当前线程向管道输出数据
					TimeUnit.SECONDS.sleep(2);
				}
			}	
		} catch (IOException e) {
			// TODO: handle exception
		}catch (InterruptedException e) {
			// TODO: handle exception
		}
	}
}