public void userSignUp(String credentials){
        String[] received = simpleprotocol.decodeMessage(credentials);
        String username = received[1];
        String password = received[2];


            if(!(userDetails.containsKey(username))){
                if(username.length() >=5 && username.length() <=20){
                    if(password.length() >= 8 && password.length() <=32){
                            userDetails.put(username, password);
                    }
                }
            }
            try{
                socket.close();
            }catch (IOException e){
                e.printStackTrace();
            }
    }