Is my code too massive?

[u/Naive_Topic_5292]

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

class server{

    private Socket s = null;
    private ServerSocket ss = null;;
    private DataInputStream din = null;
    private DataOutputStream dout = null;
    static Vector<ClientHandler> array = new Vector<>();
    private HashMap<String, String> login = new HashMap<>();
    void main(String[] args) throws IOException
    {
        // initialize
        try {
//            BufferedWriter bw = new BufferedWriter(new FileWriter("logindata.txt")); idk yet
            BufferedReader br = new BufferedReader(new FileReader("logindata.txt"));
            StringTokenizer st = null;
            String templine = "";
            String loginName = "";
            String pass = "";

            while(((templine = br.readLine()) != null)){
                st = new StringTokenizer(templine, ": ");
                if(st.hasMoreTokens()){
                    loginName = st.nextToken();
                }
                if(st.hasMoreTokens()){
                    pass = st.nextToken();
                }

                login.put(loginName, pass);
                loginName = "";
                pass = "";
            }

        }
        catch(FileNotFoundException i){
            System.out.println("Failed to initialize login file");
        }


        String receivedName = "";
        String receivedPass = ""; // <TODO> encrypt passwords after finishing filework 
        int i = 0;
        ss = new ServerSocket(5001);
        boolean userExists = false;
        while(true)
        {
            s = ss.accept();
            din = new DataInputStream(new BufferedInputStream(s.getInputStream()));
            dout = new DataOutputStream(new BufferedOutputStream(s.getOutputStream()));

            receivedName = din.readUTF();

            for(Map.Entry<String, String> entry : login.entrySet()){
                if(entry.getValue().equals(receivedName)){
                    userExists = true;
                    break;
                }
            }

            if(userExists){
                dout.writeUTF("User found, enter your password: ");
                dout.flush();
            }
            else{
                dout.writeUTF("User was not found, u may register by making a password: "); // <TODO> make a check if password was written correctly
            }
//<TODO> handle passwords
            ClientHandler client = new ClientHandler(s, receivedName, din, dout);
            System.out.println("User " + receivedName + " Accepted");

            Thread t = new Thread(client);

            array.add(client);

            t.start();

            i++;
        }

    }
}

So I'm making a simple messenger as my first project, though now when I'm working on it it seems VERY massive to me, is it normal in other projects or am I supposed to break it into smaller parts?

[u/Potential-Still]

If this is the entire program then it's fine.