Thread--线程间通信--管道

在Java语言中提供了各种各样的输入/输出流Stream，使我们能够方便的对数据进行操作，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，另一个线程从输入管道中读数据。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)PipedInputStream和PipedOutputStream

package pipeInputOutput;

import java.io.PipedOutputStream;

public class WriteData {
    
    public void writeMethod(PipedOutputStream out) {
        try {
            System.out.println("write :");
            for(int i=0; i<30000; i++) {
                String outData = "" + (i+1);
                out.write(outData.getBytes());
                System.out.print(outData);
            }
            System.out.println();
            out.close();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }

}

package pipeInputOutput;

import java.io.PipedInputStream;

public class ReadData {
    
    public void readMethod(PipedInputStream in) {
        try {
            byte[] byteArray = new byte[20];
            int readLength = in.read(byteArray);
            while(readLength != -1) {
                System.out.print("read :");
                String newData = new String(byteArray, 0, readLength);
                System.out.println(newData);
                readLength = in.read(byteArray);
            }
            System.out.println();
            in.close();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }

}

package pipeInputOutput;

import java.io.PipedOutputStream;

public class ThreadWrite extends Thread {

    private WriteData write;
    private PipedOutputStream out;

    public ThreadWrite(WriteData write, PipedOutputStream out) {
        super();
        this.write = write;
        this.out = out;
    }

    @Override
    public void run() {
        write.writeMethod(out);
    }
    
    

}

package pipeInputOutput;

import java.io.PipedInputStream;

public class ThreadRead extends Thread {

    private ReadData read;
    private PipedInputStream in;

    public ThreadRead(ReadData read, PipedInputStream in) {
        super();
        this.read = read;
        this.in = in;
    }

    @Override
    public void run() {
        read.readMethod(in);
    }

}

package pipeInputOutput;

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

public class Run {
    
    public static void main(String[] args) {
        try {
            WriteData writeData = new WriteData();
            ReadData readData = new ReadData();
            
            PipedInputStream inputStream = new PipedInputStream();
            PipedOutputStream outputStream = new PipedOutputStream();
            
            outputStream.connect(inputStream);
            
//            outputStream.write("hello world".getBytes());
//            byte[] bs = new byte[100];
//            int i = inputStream.read(bs);
//            System.out.println(new String(bs,0,i));
            
            ThreadRead threadRead = new ThreadRead(readData, inputStream);
            threadRead.start();
            
            Thread.sleep(2000);
            
            ThreadWrite threadWrite = new ThreadWrite(writeData, outputStream);
            threadWrite.start();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }

}

2)PipedReader和PipedWriter

package pipeReaderWriter;

import java.io.PipedWriter;

public class WriteData {
    
    public void writeMethod(PipedWriter out) {
        try {
            System.out.println("write :");
            for(int i=0; i<300; i++) {
                String outData = "" + (i+1);
                out.write(outData);
                System.out.println(outData);
            }
            System.out.println();
            out.close();
        } catch (Exception e) {
            // TODO: handle exception
            e.printStackTrace();
        }
    }

}

package pipeReaderWriter;

import java.io.PipedReader;

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

}

package pipeReaderWriter;

import java.io.PipedWriter;

public class ThreadWrite extends Thread {

    private WriteData write;
    private PipedWriter out;

    public ThreadWrite(WriteData write, PipedWriter out) {
        super();
        this.write = write;
        this.out = out;
    }

    @Override
    public void run() {
        write.writeMethod(out);
    }

}

package pipeReaderWriter;

import java.io.PipedReader;

public class ThreadRead extends Thread {

    private ReadData read;
    private PipedReader in;

    public ThreadRead(ReadData read, PipedReader in) {
        super();
        this.read = read;
        this.in = in;
    }

    @Override
    public void run() {
        read.readMethod(in);
    }

}

package pipeReaderWriter;

import java.io.PipedReader;
import java.io.PipedWriter;

public class Run {

    public static void main(String[] args) {
        try {
            WriteData writeData = new WriteData();
            ReadData readData = new ReadData();
            
            PipedWriter out = new PipedWriter();
            PipedReader in = new PipedReader();
            
            in.connect(out);
            
            ThreadRead threadRead = new ThreadRead(readData, in);
            threadRead.start();
            
            Thread.sleep(2000);
            
            ThreadWrite threadWrite = new ThreadWrite(writeData, out);
            threadWrite.start();
            
        } catch (Exception e) {
            // TODO: handle exception
        }
    }
    
}