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
         }
     }

 }