java管道使用

        由于java语言的stream严格区分为inputstream和outputstream，流数据读写之间转换一般使用临时文件方式来转换。但是这种方式使用的效率比较低，因此可以使用管道来实现。

       java管道支持比较弱，需要多线程来支持，例如： 

      

import java.io.*;

class Read implements Runnable

{

        private PipedInputStream in;

        Read(PipedInputStream in)

        {

                this.in = in;

        }

        public  void run()

        {

                try

                {

                        byte[] buf = new byte[1024];

                        int len = in.read(buf);

                        String s = new String(buf,0,len);

                        System.out.println(s);

                        in.close();

                }

                catch(IOException e)

                {

                        throw new RuntimeException("read failed");

                }

        }

}

class Write implements Runnable

{

        private PipedOutputStream out;

        Write(PipedOutputStream out)

        {

                this.out. = out ;

        

        }

        public void run()

        {

                try

                {

                        out.write("piped  come here"),getBytes());

                        out.close();

                }

                catch(IOException e)

                {

                        throw new RuntimeException("piped out failed");

                }

        }

}

class PipedStreamDemo

{

        public static void main(String[] args) throws IOException

        {

                PipedInputStream in = new PipedInputStream();

                PipedOutputStream out = new PipedOutputStream();

                in.connect(out);

                Read r = new Read();

                Write w = new Write();

                Thread t1 = new Thread(r);

                Thread t2 = new Thread(w);

                t1.start();

                t2.start();

                

        }

}

    由于jdk6之前版本支持1024为pipesize，之后的版本可以支持定制pipesize，调用方式为：PipedInputStream(int pipeSize)