第六章：源代码

天下维客，你可以修改的网络知识库

构建自己的java库编辑 内容： 第一章：教程提示 第二章：库简介 第三章：设计问题之封装 第四章：设计问题之可扩展性 第五章：设计问题之调试信息 第六章：源代码 结束语 其他资源： 构建自己的java库 从0到J2EE -- Java 学习历程 J2EE

样本库

在结束之前，先看一下完整的源代码，它包括了 EchoServer、mylib.Server 和 mylib.Reporter。

EchoServer

// $Id$

import java.io.*; import java.net.*; import mylib.*;

public class EchoServer extends Server {

 public EchoServer( int port ) {
   // The superclass knows what to do with the port number, we
   // don't have to care about it
   super( port );
 }

 // This is called by the Server class when a connection
 // comes in.  "in" and "out" come from the incoming socket
 // connection
 public void handleConnection( Socket socket ) {
   try {
     InputStream in = socket.getInputStream();
     OutputStream out = socket.getOutputStream();

     // just copy the input to the output
     while (true)
       out.write( in.read() );

   } catch( IOException ie ) {
     System.out.println( ie );
   }
 }

 protected void cleanUp() {
   System.out.println( "Cleaning up" );
 }

 static public void main( String args[] ) throws Exception {
   // Grab the port number from the command-line
   int port = Integer.parseInt( args[0] );

   // Have debugging info sent to standard error stream
   Server.setDebugStream( System.err );

   // Create the server, and it's up and running
   new EchoServer( port );
 }

}

mylib.Server

// $Id$

package mylib;

import java.io.*; import java.net.*;

abstract public class Server implements Runnable {

 // the port we'll be listening on
 private int port;

 // how many connections we've handled
 int numConnections;

 // the Reporter that's reporting on this Server
 private Reporter reporter;

 // set this to true to tell the thread to stop accepting
 // connections
 private boolean mustQuit = false;

 public Server( int port ) {
   // remember the port number so the thread can
   // listen on it
   this.port = port;

   // the constructor starts a background thread
   new Thread( this ).start();

   // and start a reporter
   reporter = new Reporter( this );
 }

 // this is our background thread
 public void run() {
   ServerSocket ss = null;
   try {

     // get ready to listen
     ss = new ServerSocket( port );

   while (!mustQuit) {

       // give out some debugging info
       debug( "Listening on "+port );

       // wait for an incoming connection
       Socket s = ss.accept();

       // record that we got another connection
       numConnections++;

       // more debugging info
       debug( "Got connection on "+s );

       // process the connection -- this is implemented
       // by the subclass
       handleConnection( s );
     }
   } catch( IOException ie ) {
     debug( ie.toString() );
   }
   
   debug( "Shutting down "+ss );

   cleanUp();
 }

 // the default implementation does nothing
 abstract public void handleConnection( Socket s );

 // tell the thread to stop accepting connections
 public void close() {
   mustQuit = true;
   reporter.close();
 }

 // Put any last-minute clean-up stuff in here
 protected void cleanUp() {
 }

 // everything below provides a simple debug system for
 // this package

 // set this to a print stream if you want debug info
 // sent to it; otherwise, leave it null
 static private PrintStream debugStream;

 // we have two versions of this ...
 static public void setDebugStream( PrintStream ps ) {
   debugStream = ps;
 }

 // ... just for convenience
 static public void setDebugStream( OutputStream out ) {
   debugStream = new PrintStream( out );
 }

 // send debug info to the print stream, if there is one
 static public void debug( String s ) {
   if (debugStream!= null)
     debugStream.println( s );
 }

}

mylib.Reporter

// $Id$

package mylib;

class Reporter implements Runnable {

 // the Server we are reporting on
 private Server server;

 // our background thread
 private Thread thread;

 // set this to true to tell the thread to stop accepting
 // connections
 private boolean mustQuit = false;

 Reporter( Server server ) {
   this.server = server;

  // create a background thread
   thread = new Thread( this );
   thread.start();
 }

 public void run() {
   while (!mustQuit) {
     // do the reporting
     Server.debug( "server has had "+server.numConnections+" connections" );

     // then pause a while
     try {
       Thread.sleep( 5000 );
     } catch( InterruptedException ie ) {}
   }
 }

 // tell the background thread to quit
 public void close() {
   mustQuit = true;
 }

}

返上层