标签：tostring nts 缓存 stat 简单的 tst 打印 override xtend
PipedInputStream和PipedOutputStream分别是管道输入流和管道输出流.
它们的作用是让多线程之间可以通过管道进行通讯,在使用管道通信时,必须将PipedInputStream和PipedOutputStream配合使用.
使用管道通信时,大致流程是:线程A向PipedOutputStream中写入数据,这些数据会自动的发送到对应的pipedInputStream中进行缓存,此时,线程B通过读取PipedInputStream中的数据,就可以实现线程通信了.
实验一:发送简短的消息
Sender.java(发送消息)
public class Sender extends Thread { private PipedOutputStream pos = new PipedOutputStream(); public Sender(PipedOutputStream pos) { this.pos = pos; } @Override public void run() { sendShortMessage(); } // 发送简单的消息 public void sendShortMessage() { try { pos.write("你好啊!".getBytes()); } catch (IOException e) { e.printStackTrace(); } finally { try { pos.close(); } catch (IOException e) { e.printStackTrace(); } } } }
Reciver.java(接受消息)
public class Reciver extends Thread { private PipedInputStream pis = new PipedInputStream(); public Reciver(PipedInputStream pis) { this.pis = pis; } @Override public void run() { byte[] buf = new byte[2048]; try { pis.read(buf); pis.close(); } catch (IOException e) { e.printStackTrace(); } System.out.println("Reciver :" + new String(buf)); } }
PipedTest.java
public class PipedTest { public static void main(String[] args) throws IOException { PipedOutputStream pipedOutputStream = new PipedOutputStream(); PipedInputStream pipedInputStream = new PipedInputStream(); Sender sender = new Sender(pipedOutputStream); Reciver reciver = new Reciver(pipedInputStream); pipedInputStream.connect(pipedOutputStream); sender.start(); reciver.start(); } } //Reciver :你好啊!
实验一很好理解:
pipedInputStream.connect(pipedOutputStream);方法把PipedOutPutStream和PipedInputStream关联了起来.
Sender通过write()方法,向PipedInputStream中写入"你好啊!",查看PipedOutputStream的writer()方法可知,其实是调用了PipedinputStream的receive()方法,继续查看该方法可知,PipedinputStream的
receive()方法,其实就是把数据保存到自己的byte buffer[]数组中,而且其数组的默认大小为1024.
Reciver通过read()方法,从自己的byte buffer[]数组中读取数据.
实验二:发送较长的消息
Sender.java(发送消息)
public class Sender extends Thread { private PipedOutputStream pos = new PipedOutputStream(); public Sender(PipedOutputStream pos) { this.pos = pos; } @Override public void run() { sendShortMessage(); } // 发送较长的消息 public void sendLongMessage() { StringBuilder sb = new StringBuilder(); // 总共长度是1020个字节 for (int i = 0; i < 102; i++) { sb.append("0123456789"); } // 再写入26个字节。 sb.append("abcdefghijklmnopqrstuvwxyz"); // str的总长度是1020+26=1046个字节 String str = sb.toString(); try { pos.write(str.getBytes()); } catch (IOException e) { e.printStackTrace(); } finally { try { pos.close(); } catch (IOException e) { e.printStackTrace(); } } } }
Reciver.java(接受消息)
public class Reciver extends Thread { private PipedInputStream pis = new PipedInputStream(); public Reciver(PipedInputStream pis) { this.pis = pis; } @Override public void run() { byte[] buf = new byte[2048]; try { pis.read(buf); pis.close(); } catch (IOException e) { e.printStackTrace(); } System.out.println("Reciver :" + new String(buf)); } }
PipedTest.java
public class PipedTest { public static void main(String[] args) throws IOException { PipedOutputStream pipedOutputStream = new PipedOutputStream(); PipedInputStream pipedInputStream = new PipedInputStream(); Sender sender = new Sender(pipedOutputStream); Reciver reciver = new Reciver(pipedInputStream); pipedInputStream.connect(pipedOutputStream); sender.start(); reciver.start(); } }
实验二的运行结果为:Reciver :012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789abcd
发现收到的数据少了"efghijklmnopqrstuvwxyz",为什么打印出来的数据正好是1024长度.其实上面我们已经说过了,PipedInputStream的byte [] buffer数组的默认长度只有1024,所以上面的输出是这样的.那怎么改才能输出全部内容的?
我们修改Reciver.java
public class Reciver extends Thread { private PipedInputStream pis = new PipedInputStream(); public Reciver(PipedInputStream pis) { this.pis = pis; } @Override public void run() { reciverLongMessage(); } public void reciverLongMessage() { while (true) { byte[] buf = new byte[1024]; int len; try { len = pis.read(buf); if (len > 0) { System.out.println(new String(buf, 0, len)); } else { break; } } catch (IOException e) { try { pis.close(); } catch (IOException e2) { e2.printStackTrace(); } } } } }
这样就可以正确输出结果啦!
字节输入流/输出流-----PipedInputStream/PipedOutputStream
标签：tostring nts 缓存 stat 简单的 tst 打印 override xtend
原文地址：https://www.cnblogs.com/zhangj-ymm/p/9860674.html
