TCP Client problems

Hello. I'm trying to figure out why my TCP Client code isnt working. I've built the server end of it also. Unfortunately I get this error when I try to run.

java TCPAdditionClient
Exception in thread "main" java.net.ConnectException: Connection refused: connect
at java.net.DualStackPlainSocketImpl.connect0(Native Method)
at java.net.DualStackPlainSocketImpl.socketConnect(Un known Source)
at java.net.AbstractPlainSocketImpl.doConnect(Unknown Source)
at java.net.AbstractPlainSocketImpl.connectToAddress( Unknown Source)
at java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.net.PlainSocketImpl.connect(Unknown Source)
at java.net.SocksSocketImpl.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.connect(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at java.net.Socket.<init>(Unknown Source)
at TCPAdditionClient.main(TCPAdditionClient.java:10)

Can anyone please let me know what I'm doing wrong here?

Here is my Client code:

Code:

---

                String sentence;
                  String modifiedSentence;
                  BufferedReader inFromUser = new BufferedReader( new InputStreamReader(System.in));
                  Socket clientSocket = new Socket("localhost", 4567);
                  DataOutputStream outToServer = new DataOutputStream(clientSocket.getOutputStream());
                  BufferedReader inFromServer = new BufferedReader(new InputStreamReader(clientSocket.getInputStream()));
                  sentence = inFromUser.readLine();
                  outToServer.writeBytes(sentence + '\n');
                  modifiedSentence = inFromServer.readLine();
                  System.out.println("FROM SERVER: " + modifiedSentence);
                  clientSocket.close();

---

Here is my server code:

Code:

---

int open = 1; int var= 0;
                String clientSentence; String capitalizedSentence;
                ServerSocket welcomeSocket = new ServerSocket(var);
               
//Checks presence of argument
            if(args.length !=0){
                        var = (Integer.valueOf(args[0]));
                              }
           
//Throws Exception if Argument is not present
            if(args.length == 0){
                    throw new IllegalArgumentException("You need to specify a port number when executing program...  Example: \"java IntCountServer 1234\" Please try again");
                                }
           
//Accepts and reads input from client           
            while(open == 1)
        {
          Socket connectionSocket = welcomeSocket.accept();
          BufferedReader inFromClient =
              new BufferedReader(new InputStreamReader(connectionSocket.getInputStream()));
          DataOutputStream outToClient = new DataOutputStream(connectionSocket.getOutputStream());
          clientSentence = inFromClient.readLine();
          System.out.println("Data received from client: " + clientSentence);
          capitalizedSentence = clientSentence.toUpperCase() + '\n';
          outToClient.writeBytes(capitalizedSentence);

---

I fixed it!