一个线程发送数据到输出管道，另一个线程从输入管道中读取数据。通过使用管道，实现不同线程间的通信，而无须借助于类似临时文件之类的东西。

    在java的jdk中提供了4个类来使线程间可以进行通信：         PipedInputStream 和 PipedOutputStream         PipedReader 和 PipedWriter

public static class ReadClient implements Runnable{	private PipedInputStream reader;	public ReadClient(PipedInputStream reader) {		this.reader = reader;	}	@Override	public void run() {		byte[] bytes = new byte[50];		try {			do {				int readLength = reader.read(bytes);//方法会一直阻塞，直到有数据被写入				if(readLength==-1){continue;}				String message = new String(bytes,0,readLength);				System.out.println("get: "+message);			}while(true);		} catch (IOException e) {			//something 		}finally{			try {				reader.close();			} catch (IOException e) {				//something 			}		}	}}public static class WriteClient implements Runnable{	private PipedOutputStream writer;	public WriteClient(PipedOutputStream writer) {		this.writer = writer;	}	@Override	public void run() {		int seed = 0;		try {			while (true) {				seed++;				String message = ""+seed;				System.out.println("send: "+seed);				writer.write(message.getBytes());				writer.flush();				Thread.sleep(1000);			}		} catch (InterruptedException | IOException e) {			//something 		}finally{			try {				writer.close();			} catch (IOException e) {				//something 			}		}			}	}public static void main(String[] args) throws InterruptedException, IOException {	PipedInputStream inputStream = new PipedInputStream();	PipedOutputStream outputStream = new PipedOutputStream();	//管道连接	inputStream.connect(outputStream); //或 outputStream.connect(inputStream);	//创建读写线程	Thread reader = new Thread(new ReadClient(inputStream));	reader.start();	Thread.sleep(2000);	Thread writer = new Thread(new WriteClient(outputStream));	writer.start();	}

结果：

send: 1 get: 1 send: 2 get: 2 send: 3 get: 3

在main方法中，读的线程先启动了，所以在read时会阻塞直到writer线程开始写数据。如果writer先启动，数据也不会丢失，会一直写入到管道中。直到reader线程去读取它。