client

package tcpclientapp;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

public class TCPClientApp {
    public static void main(String[] args) {
        //Name of the host that we are going to connect to
        String hostName = "127.0.0.1";
        //Make sure that this port is the same as
        //the server listening port
        int port =  12345;


        while(true) {
            Scanner reader = new Scanner(System.in);
            // Reading from System.in
            System.out.println("Please input a command: ");
            String request = reader.nextLine(); // Scans the next token of the input as an int.
            //once finished
            reader.close();
            try {
                //Use socket to connect to the server
                Socket socket = new Socket(hostName, port);
                //Access to the output stream
                OutputStream os = socket.getOutputStream();
                //Write lie
                PrintWriter pw = new PrintWriter(os);
                pw.println(request);
                pw.flush(); //Read response.
                InputStream is = socket.getInputStream();
                //Read characters
                InputStreamReader isr = new InputStreamReader(is);
                //Read lines
                BufferedReader br = new BufferedReader(isr);
                String header = br.readLine();
                System.out.println("Response: " +  header );
                }
            catch (IOException ex) {
                ex.printStackTrace();
            }

        }





        /*
        Boolean valid = true;
        String test = "divide 2 0";
        String cmd ="";
        String arg1 ="";
        String arg2 ="";
        int num1 = 0;
        int num2 = 0;
        String response = "";
        if(test.contains(" ")){
            cmd= test.substring(0, test.indexOf(" "));

            if(valid){
                test = test.substring(test.indexOf(" ")+1);

                if(test.contains(" ")){
                    arg1 = test.substring(0, test.indexOf(" "));
                    arg2 = test.substring(test.indexOf(" ")+1);
                    //Checks if the args convert to numbers otherwise returns error
                    try {
                        num1 = Integer.parseInt(arg1);
                    }
                    catch( Exception e ) {
                        response = "Error: \""+arg1+"\" is not a number";
                        valid = false;
                    }
                    try {
                        num2 = Integer.parseInt(arg2);
                    }
                    catch( Exception e ) {
                        response = "Error: \""+arg2+"\" is not a number";
                        valid = false;
                    }
                }
                else{
                    response = "Result: Invalid number of arguments";
                    valid = false;
                }
            }
        }
        int res = 0;
        if(cmd.equalsIgnoreCase("add")){
            res = num1+num2;
            response = "The add result is: "+ res;
        }
        else if(cmd.equalsIgnoreCase("subtract")){
            res = num1-num2;
            response = "The substract result is: "+ res;
        }
        else if(cmd.equalsIgnoreCase("multiply")){
            res = num1*num2;
            response = "The multiply result is: "+ res;
        }
        else if(cmd.equalsIgnoreCase("divide")){
            if(num2==0){
                response = "Error: Divided by zero exception";
            }
            else{
                res = num1/num2;
                response = "The divide result is: "+ res;
            }
        }
        else{
            response =  "Error: Invalid command \""+cmd+"\"";
            valid = false;
        }
        System.out.println(response);
        */
    }
}