上一章節(jié)講了wait/notify通信，這一節(jié)我們來探討使用管道進行通信。
java中提供了IO流使我們很方便的對數(shù)據(jù)進行操作，pipeStream是一種特殊的流，用于不同線程間直接傳送數(shù)據(jù)。一個線程將數(shù)據(jù)發(fā)送到輸出管道，另一個線程從輸入管道讀取數(shù)據(jù)。通過管道實現(xiàn)通信不需要借助臨時文件這類東西。
java中提供了四個類使得線程間可以通信：
①字節(jié)流：PipeInputStream，PipedOutputStream
②字符流：PipedReader，PipedWriter
下面我們看看字節(jié)流的實現(xiàn)方法：
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package pipeInputOutput;//輸出流import java.io.IOException;import java.io.PipedOutputStream;public class WriteDate { public void writeMethod(PipedOutputStream out) { try { System.out.println("write:"); for(int i=0;i<300;i++) { String outDate=""+(i+1); out.write(outDate.getBytes()); System.out.print(outDate); } System.out.println(); out.close(); }catch(IOException e) { e.printStackTrace(); } }} |
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package pipeInputOutput;//輸入流import java.io.IOException;import java.io.PipedInputStream;public class ReadDate { public void ReadDate(PipedInputStream input) { try { System.out.println("read:"); byte[] byteArray=new byte[20]; int readLength=input.read(byteArray); while(readLength!=-1) { String newDate=new String(byteArray,0,readLength); System.out.print(newDate); readLength=input.read(byteArray); } System.out.println(); input.close(); }catch(IOException e){ e.printStackTrace(); } }} |
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package pipeInputOutput;import java.io.PipedOutputStream;//輸出線程public class ThreadWrite extends Thread { private WriteDate write; private PipedOutputStream out; public ThreadWrite(WriteDate write,PipedOutputStream out) { super(); this.write=write; this.out=out; } public void run() { write.writeMethod(out); }} |
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package pipeInputOutput;import java.io.PipedInputStream;//輸入線程public class ThreadRead extends Thread{ private ReadDate read; private PipedInputStream in; public ThreadRead(ReadDate read,PipedInputStream in) { super(); this.read=read; this.in=in; } public void run() { read.ReadDate(in); }} |
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package pipeInputOutput;import java.io.IOException;import java.io.PipedInputStream;import java.io.PipedOutputStream;//測試方法public class Run { public static void main(String[] args) { try { WriteDate write=new WriteDate(); ReadDate read=new ReadDate(); PipedInputStream inputStream=new PipedInputStream(); PipedOutputStream outputStream=new PipedOutputStream(); //輸出流與輸入流進行連接。 outputStream.connect(inputStream); //inputStream.connect(outputStream); ThreadRead readThread=new ThreadRead(read,inputStream); readThread.start();//先啟動輸出線程 Thread.sleep(2000); ThreadWrite writeThread=new ThreadWrite(write,outputStream); writeThread.start();//后啟動輸入線程 } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } }} |
控制臺輸出：
read:
write:
123456789101112131415161718192021...
123456789101112131415161718192021...
上面測試中，先啟動輸入線程，然后因為沒有線程被寫入所以線程被阻塞，知道有數(shù)據(jù)寫入。
我們接著繼續(xù)看看字符流的實現(xiàn)方法：
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package pipeInputOutput1;import java.io.IOException;import java.io.PipedWriter;//字符輸出流public class WriteDate { public void writeMethod(PipedWriter out) { try { System.out.println("write:"); for(int i=0;i<300;i++) { String outDate=""+(i+1); out.write(outDate); System.out.print(outDate); } System.out.println(); out.close(); }catch(IOException e) { e.printStackTrace(); } }} |
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package pipeInputOutput1;import java.io.IOException;import java.io.PipedReader;//字符輸入流public class ReadDate { public void readMethod(PipedReader in) { try { System.out.println("read:"); char[] byteArray=new char[20]; int readLength=in.read(byteArray); while(readLength!=-1) { String newDate=new String(byteArray,0,readLength); System.out.print(newDate); readLength=in.read(byteArray); } System.out.println(); in.close(); } catch (IOException e) { e.printStackTrace(); } }} |
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package pipeInputOutput1;import java.io.PipedWriter;//輸出流線程public class WriteThread extends Thread { private WriteDate write; private PipedWriter out; public WriteThread(WriteDate write,PipedWriter out) { super(); this.write=write; this.out=out; } public void run() { write.writeMethod(out); }} |
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package pipeInputOutput1;import java.io.PipedReader;//輸入流線程public class ReadThread extends Thread{ private ReadDate read; private PipedReader in; public ReadThread(ReadDate read,PipedReader in) { super(); this.read=read; this.in=in; } public void run() { read.readMethod(in); }} |
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package pipeInputOutput1;import java.io.IOException;import java.io.PipedReader;import java.io.PipedWriter;//測試方法public class run { public static void main(String[] args) { try { WriteDate write=new WriteDate(); ReadDate read=new ReadDate(); PipedWriter out=new PipedWriter(); PipedReader in=new PipedReader(); //連接輸出流與輸入流 out.connect(in); //in.connect(out); ReadThread threadread=new ReadThread(read,in); threadread.start(); Thread.sleep(2000); WriteThread threadwrite=new WriteThread(write,out); threadwrite.start(); } catch (IOException e) { e.printStackTrace(); } catch (InterruptedException e) { e.printStackTrace(); } }} |
字符流額字節(jié)流大同小異，上面的例子中字符流不需要創(chuàng)建字節(jié)數(shù)組而已。
以上就是本文的全部內(nèi)容，希望對大家的學(xué)習有所幫助，也希望大家多多支持服務(wù)器之家。
原文鏈接：http://blog.csdn.net/qq_39266910/article/details/78201810
