Java多线程-管道流实现线程间通信

Posted 2021-03-04 Alan Lau

管道流实现线程间通信

管道流

在Java语言中提供了各种各样的输入/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流，另一个线程从输入管道流中读取数据。

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。

字节流

PipedInputStream 和 PipedOutputStream

字符流

PipedReader 和 PipedWriter

 

示例：

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

        PipedReader reader = new PipedReader();
        PipedWriter writer = new PipedWriter();

        writer.connect(reader);

        new Thread(() -> {
            writeData.writeMethod(writer);
        }).start();

        Thread.sleep(2000);

        new Thread(() -> {
            readData.readMethod(reader);
        }).start();
    }

    static class WriteData {
        public void writeMethod(PipedWriter writer) {
            try {
                System.out.println("write :");
                for (int i = 0; i < 300; i++) {
                    String outData = "" + (i + 1);
                    writer.write(outData);
                    System.out.print(outData);
                }
                System.out.println();
                writer.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    static class ReadData {
        public void readMethod(PipedReader reader) {
            try {
                System.out.println("read :");
                char[] byteArray = new char[20];
                int readLength = reader.read(byteArray);
                while (readLength != -1) {
                    String newData = new String(byteArray, 0, readLength);
                    System.out.print(newData);
                    readLength = reader.read(byteArray);
                }
                System.out.println();
                reader.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }
}

运行结果如下：