前言

Github：https://github.com/yihonglei/thinking-in-concurrent

一 PipedOutputStream和PipedInputStream简介

PipedOutputStream和PipedInputStream通过字节流实现线程间的通信，

通过PipedOutputStream.connect(PipedInputStream snk)或PipedInputStream.connect(PipedOutputStream src)建立连接。

二代码实例

1、使用PipedOutputStream输出流写入数据

package com.jpeony.concurrent.piped;

import java.io.IOException;
import java.io.PipedOutputStream;

/**
 * 写入数据
 *
 * @author yihonglei
 */
public class WriteData {
    public void writeMethod(PipedOutputStream out) throws IOException {
        try {
            String outData = "I love you";
            out.write(outData.getBytes());
            System.out.println("写入数据:" + outData);
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭输出流
            out.close();
        }
    }
}

2、使用PipedInputStream输入流读出数据

package com.jpeony.concurrent.piped;

import java.io.IOException;
import java.io.PipedInputStream;

/**
 * 读出数据
 *
 * @author yihonglei
 */
public class ReadData {
    public void readMethod(PipedInputStream input) throws IOException {
        try {
            byte[] byteArray = new byte[20];
            int readLength = input.read(byteArray);
            while (readLength != -1) {
                String newData = new String(byteArray, 0, readLength);
                System.out.println("读出数据:" + newData);
                readLength = input.read(byteArray);
            }
        } catch (IOException e) {
            e.printStackTrace();
        } finally {
            // 关闭流
            input.close();
        }
    }
}

3、写入数据线程

package com.jpeony.concurrent.piped;

import java.io.IOException;
import java.io.PipedOutputStream;

/**
 * 写入数据线程
 *
 * @author yihonglei
 */
public class WriteThread extends Thread {
    private WriteData writeData;
    private PipedOutputStream out;

    public WriteThread(WriteData writeData, PipedOutputStream out) {
        this.writeData = writeData;
        this.out = out;
    }

    @Override
    public void run() {
        try {
            writeData.writeMethod(out);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

4、读出数据线程

package com.jpeony.concurrent.piped;

import java.io.IOException;
import java.io.PipedInputStream;

/**
 * 读出数据线程
 *
 * @author yihonglei
 */
public class ReadThread extends Thread {
    private ReadData readData;
    private PipedInputStream input;

    public ReadThread(ReadData readData, PipedInputStream input) {
        this.readData = readData;
        this.input = input;
    }

    @Override
    public void run() {
        try {
            readData.readMethod(input);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

5、测试类

package com.jpeony.concurrent.piped;

import java.io.IOException;
import java.io.PipedInputStream;
import java.io.PipedOutputStream;

/**
 * 测试类
 *
 * @author yihonglei
 */
public class RunTest {
    public static void main(String[] args) {
        try {
            WriteData writeData = new WriteData();
            ReadData readData = new ReadData();

            PipedInputStream inputStream = new PipedInputStream();
            PipedOutputStream outputStream = new PipedOutputStream();

            /*
             * 通过 inputStream.connect(outputStream)
             * 或
             * outputStream.connect(inputStream)
             * 使得两个Stream之间产生通信链接，进行数据交换输出与输入。
             */
            // inputStream.connect(outputStream);
            outputStream.connect(inputStream);

            ReadThread readThread = new ReadThread(readData, inputStream);
            readThread.start();

            // 休眠1秒
            Thread.sleep(1000);

            WriteThread writeThread = new WriteThread(writeData, outputStream);
            writeThread.start();
        } catch (IOException | InterruptedException e) {
            e.printStackTrace();
        }
    }
}

6、运行结果