//  Example of a Concurrent Server using TCP. The server
//  accepts a client and serves the client in a separate 
//  thread, allowing it to continue to accept other clients
//  and serve them likewise. The service being provided to 
//  clients is a simple capitalization of string.
//  Run Server as:
//      java ConTCPServer <server_port>
import java.io.*; 
import java.net.*; 

class ConTCPServer { 

    public static void main(String args[]) throws Exception 
    { 
	
   	ServerSocket welcomeSocket =
                     new ServerSocket(java.lang.Integer.parseInt(args[0])); 

      while(true) { 
	   Socket connectionSocket = welcomeSocket.accept(); 
	   Servant newServant = new Servant(connectionSocket);
	   // try
	   // BetterServant newServant = new BetterServant(connectionSocket);
      } 
    } 
} 

class Servant extends Thread
{
    private String clientSentence; 
    private String capitalizedSentence; 
    private Socket SocketToClient;

    public Servant (Socket sock)
	{
	    SocketToClient = sock;
	    start();
	}
    public void run()
	{
    try {
		BufferedReader inFromClient = 
		    new BufferedReader(new  
                   InputStreamReader(SocketToClient.getInputStream())); 
		
		DataOutputStream  outToClient = 
		    new DataOutputStream(SocketToClient.getOutputStream());
		while (true) {
		    clientSentence = inFromClient.readLine(); 
		    
		    capitalizedSentence = clientSentence.toUpperCase() + '\n'; 
		    
		    outToClient.writeBytes(capitalizedSentence); 
		}
    }
    catch (IOException e) {
		System.out.println("Socket problems");
    }
	}
}
	    
class BetterServant implements Runnable 
{
    private String clientSentence; 
    private String capitalizedSentence; 
    private Socket SocketToClient;
    Thread myThread;

    public BetterServant (Socket sock)
	{
	    SocketToClient = sock;
	    myThread = new Thread(this);
	    myThread.start();
	}
    public void run()
	{
	    try {
		BufferedReader inFromClient = 
		    new BufferedReader(new InputStreamReader(SocketToClient.getInputStream())); 
		
		DataOutputStream  outToClient = 
		    new DataOutputStream(SocketToClient.getOutputStream());
		while (true) {
		    clientSentence = inFromClient.readLine(); 
		    
		    capitalizedSentence = clientSentence.toUpperCase() + '\n'; 
		    
		    outToClient.writeBytes(capitalizedSentence); 
		}
	    }
	    catch (IOException e) {
		System.out.println("Socket problems");
	    }
	}
}