Server.java

import java.io.*;
import java.net.*;
import java.util.*;
import javax.imageio.IIOException;
public class Server
{
    private String[] serverArgs;
    public Socket socket;
    public Socket fileSocket;
    public boolean keepRunning = true;
    public int ConnectOnce = 0;
    public String option = "";
    public boolean isConnected = false;
    public Server(String[] args) throws IOException
    {
        this.serverArgs = args;
        if(ConnectOnce == 0)
        {
            int port_number1 = Integer.valueOf(serverArgs[1]);
            ServerSocket serverSocket = new ServerSocket(port_number1);
            socket = serverSocket.accept();
            ConnectOnce = 4;
            isConnected = true;
        }
    }
    public void serverRun2(String[] args) throws IOException
    {
        serverArgs = args;
        serverArgs = Arrays.copyOf(args, args.length);
        serverSend.start();
    }
    Thread serverSend = new Thread()
    {
        public void run()
        {
            OutputOptions();
            while(isConnected)
            {
                try
                {
                   ServerRecieve serverThread = new ServerRecieve(socket);
                   serverThread.start();
                   DataInputStream userKeyboardInput = new DataInputStream(System.in);
                   String line2 = userKeyboardInput.readLine();
                   if(line2.equals("m") || line2.equals("M"))
                   {
                        ServerSend();
                   }
                   else if(line2.equals("f") || line2.equals("F"))
                   {
                       FileRequest();
                   }
                   else if(line2.equals("x") || line2.equals("X"))
                   {
                       isConnected = false;
                       System.exit(0);
                       break;
                   }
                   else if(!line2.equals("x") && !line2.equals("X") && !line2.equals("m")
                           && !line2.equals("M") && !line2.equals("f") && !line2.equals("F"))
                   {
                       System.out.println("(invalid choice)");
                   }
               }
               catch ( Exception e )
               {
                   System.out.println( e.getMessage() );
               }
            }
        }
    };
public void ServerSend()
{
        try
        {
            DataInputStream userKeyboardInput = new DataInputStream(System.in);
            DataOutputStream output = new DataOutputStream(socket.getOutputStream());
            System.out.println("Enter your message:");
            String newMessage = userKeyboardInput.readLine();
            if(newMessage!=null && !newMessage.isEmpty())
            {
                output.writeUTF(newMessage);
            }
            output.flush();
            StandardInput();
        }
        catch (IOException e)
        {
            e.printStackTrace();
        }
        finally
        {
        }
}
public void FileRequest() throws FileNotFoundException
{
    try
    {
            System.out.println("Which file do you want?");

            DataInputStream userKeyboardInput = new DataInputStream(System.in);
            DataOutputStream output = new DataOutputStream(socket.getOutputStream());
            String thisFileName = userKeyboardInput.readLine();
            if(thisFileName!=null && !thisFileName.isEmpty())
            {
                DataInputStream input = new DataInputStream(socket.getInputStream());
                output.writeUTF(thisFileName + "`" + "\n");
                long file_size= input.readLong();
                System.out.println("File size is: " + file_size);
                if ( file_size == 0 )
                {
                    System.out.println("File size is 0");
                }
                FileOutputStream file_out= new FileOutputStream( thisFileName );
                int number_read;
                byte[] buffer= new byte[1500];
                while( (number_read= input.read( buffer)) != -1 )
                {
                    file_out.write( buffer, 0, number_read );
                }
                System.out.println("File " + thisFileName  + " downloaded (" + number_read + " bytes read)");
                file_out.flush();
                output.flush();
                StandardInput();
            }

    }
    catch (IOException e)
    {
        e.printStackTrace();
    }
}
void OutputOptions()
{
    System.out.println("Enter an option ('m', 'f', 'x'): ");
    System.out.println("(M)essage (send)");
    System.out.println("(F)ile (request) ");
    System.out.println("e(X)it ");
}
public void StandardInput()
{
    OutputOptions();
    while(true)
    {
        try
        {
           DataInputStream userKeyboardInput = new DataInputStream(System.in);
           String line2 = userKeyboardInput.readLine();
           if(line2.equals("m") || line2.equals("M"))
           {
                ServerSend();
           }
           else if(line2.equals("f") || line2.equals("F"))
           {
               FileRequest();
           }
           else if(line2.equals("x") || line2.equals("X"))
           {
               isConnected = false;
               System.exit(0);
               break;
           }
           else if(!line2.equals("x") && !line2.equals("X") && !line2.equals("m")
                   && !line2.equals("M") && !line2.equals("f") && !line2.equals("F"))
           {
               System.out.println("(invalid choice)");
           }
       }
       catch ( Exception e )
       {
           System.out.println( e.getMessage() );
       }
    }
}
}