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

public class EchoServer2 
{
    public static void main(String[] args) throws IOException 
    {	
        ServerSocket serverSocket = null;
        boolean listening = true;
        try 
        {
            serverSocket = new ServerSocket(1111);    
        } 
        catch (IOException e) 
        {
            System.err.println("Could not listen on port: 1111.");
            System.exit(1);
        } 

        while(listening)
        {
	    new EchoMultiServerThread(serverSocket.accept()).start();
        }
            
        serverSocket.close();
        
    }
}



24-5
EchoServerBase.Java
import java.io.*;
import java.net.*;

public class EchoServerBase 
{   
    public static void main(String[] args) throws IOException 
    {	
        (new EchoServerBase()).go();
    }
    
    public void go() throws IOException 
    {
    	boolean listening = true;
        ServerSocket serverSocket= getServerSocket();
        
        while(listening)
        {
	    new EchoMultiServerThread(serverSocket.accept()).start();
        }
            
        serverSocket.close();
    }
    
    public  ServerSocket getServerSocket()
    {
    	ServerSocket serverSocket = null;
    	
    	try 
        {
            serverSocket = new ServerSocket(1111);    
        } 
        catch (IOException e) 
        {
            System.err.println("Could not listen on port: 1111.");
            System.exit(1);
        } 
        
        return serverSocket;
        
    }
}



24-6
import java.net.*;
import java.io.*;
import java.util.*;
import java.security.*;
import Javax.net.*;
import Javax.net.ssl.*;

public class SecureEchoServer extends EchoServerBase 
{   
    
    public static void main(String[] args) throws IOException 
    {	
        (new SecureEchoServer()).go();
    }
    
    public  ServerSocket getServerSocket()
    {
    	SSLServerSocket  serverSocket = null;
    	
    	try 
        {
            String KEYSTORE = "sslkeystore";
 	    	char[] KEYSTOREPW = "12345678".toCharArray();
 	    	char[] KEYPW = "ssltest".toCharArray();
 
   	    	KeyStore keystore = KeyStore.getInstance("JKS");
  	    	keystore.load(new FileInputStream(KEYSTORE), KEYSTOREPW);
  
  	    	KeyManagerFactory kmf = KeyManagerFactory.getInstance("SunX509");
  	    	kmf.init(keystore, KEYPW);

  	   		SSLContext sslc = SSLContext.getInstance("SSLv3");

  	    	sslc.init(kmf.getKeyManagers(), null, null);
     	    ServerSocketFactory ssf = sslc.getServerSocketFactory();   
      
      	    serverSocket =(SSLServerSocket)ssf.createServerSocket(1111);
      	    System.out.println("ssl Echo server start at 1111");

        } 
        catch (Exception e) 
        {
            System.err.println("Could not listen on port: 1111.");
            System.exit(1);
        } 
        
        return serverSocket;
        
    }
}



24-7
EchoClientBase.Java
import java.io.*;
import java.net.*;

public class EchoClientBase
{
    public static void main(String[] args) throws IOException 
    {	
        (new EchoClientBase()).go();
    }
    
    public void go() throws IOException 
    {
        Socket echoSocket = null;
        PrintWriter out = null;
        BufferedReader in = null;

        try 
        {
            getSocket();
            out = new PrintWriter(echoSocket.getOutputStream(), true);
            in = new BufferedReader(new InputStreamReader(echoSocket.getInputStream()));
        } 
        catch (UnknownHostException e) 
        {
            System.err.println("Don't know about host: localhost.");
            System.exit(1);
        } 

	System.out.println(in.readLine());
	System.out.println(in.readLine());
	
	BufferedReader stdIn = new BufferedReader(
                                   new InputStreamReader(System.in));
	String userInput;

	while ((userInput = stdIn.readLine()) != null) {
	    out.println(userInput);
	    System.out.println(in.readLine());
	}

	out.close();
	in.close();
	
	echoSocket.close();
    }
    
    public  Socket getSocket() throws UnknownHostException , IOException 
    {
    	Socket echoSocket = null;
    	echoSocket = new Socket ( "localhost", 1111); 
    	return echoSocket;
    }
}