Java多线程编程3--通过管道线程间通信（字节流、字符流）

    在Java语言中提供了各种各样的输人/输出流Stream，使我们能够很方便地对数据进行操作，其中管道流(pipeStream)是一种特殊的流，用于在不同线程间直接传送数据。一个线程发送数据到输出管道，另一个线程从输人管道中读数据。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:
    1)PipedInputStream和PipedOutputStream
    2)PipedReader和PipedWriter

1、通过管道进行线程间通信：字节流/字符流

public class WriteData {
    public void writeMethod(PipedOutputStream out) { //字符流这里换成PipeWriter
        try {
            System.out.println("write :");
            for (int i=0; i<10; i++) {
                String outData = "" + (i+1);
                out.write(outData.getBytes());  //字符流这里换成out.write(outData)
                System.out.print(outData);
            }
            System.out.println();
            out.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

public class ReadData {
    public void readMethod(PipedInputStream input) {  //字符流这里换成PipedReader
        try {
            System.out.println("read: ");
            byte[] byteArray = new byte[20];  //字符流这里换成char
            int readLength = input.read(byteArray);  
            while (readLength != -1) {
                String newData = new String(byteArray, 0, readLength);
                System.out.println(newData);
                readLength = input.read(byteArray);
            }
            System.out.println();
            input.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

两个自定义线程

public class ThreadWrite extends Thread {
    private WriteData write;
    private PipedOutputStream out;  //字符流这里换成PipedWriter

    public ThreadWrite(WriteData write, PipedOutputStream out) {  //字符流这里换成PipedWriter
        this.write = write;
        this.out = out;
    }
    public void run() {
        write.writeMethod(out);
    }
}

public class ThreadRead extends Thread {
    private ReadData read;
    private PipedInputStream input;  //字符流这里换成PipedRead

    public ThreadRead(ReadData read, PipedInputStream input) { //字符流这里换成PipedRead
        this.read = read;
        this.input = input;
    }
    public void run() {
        read.readMethod(input);
    }
}

public class Run {
    public static void main(String[] args) throws InterruptedException, IOException {
        WriteData writeData = new WriteData();
        ReadData readData = new ReadData();

        PipedInputStream inputStream = new PipedInputStream();   //字符流用PipedReader
        PipedOutputStream outputStream = new PipedOutputStream();  //字符流用PipedWriter

        inputStream.connect(outputStream); //这两个只能用一个
        //outputStream.connect(inputStream);

        ThreadRead threadRead = new ThreadRead(readData,inputStream);
        threadRead.start();

        Thread.sleep(2000);

        ThreadWrite threadWrite = new ThreadWrite(writeData,outputStream);
        threadWrite.start();
    }
}

read: write : 12345678910 12345678910

使用代码inputStream.connect(outputStream)或outputStream.connect(inputStream)的作用使两个 Stream之间产生通信链接，这样才可以进行输出输入。