How to keep spaces for the encypted text

Question

class Main {
  public static void main(String[] args) {
    String alphabet = "abcdefghijklmnopqrstuvwxyz";
    String message = "how are you";
    int shift = -3;

    System.out.println(message);

    String eMessage = "";
   
    if(shift < 0) {
      int newShift = shift % 26 + 26;
      
      for (int i = 0; i < message.length(); i++) {
        int wordPosition = alphabet.indexOf(message.charAt(i));
        int numCipher = (wordPosition + newShift) % 26;
        char cipher = alphabet.charAt(numCipher);
        eMessage = eMessage + String.valueOf(cipher);
    else {  
      int newShift = shift % 26;
      for (int i = 0; i < message.length(); i++) {
        int wordPosition = alphabet.indexOf(message.charAt(i));
        int numCipher = (wordPosition + newShift) % 26;
        char cipher = alphabet.charAt(numCipher);
        eMessage = eMessage + String.valueOf(cipher);
      }
    }
      
    System.out.print(eMessage);
  }
}

It works for single words, but when i type a full sentence the encrypted version of the message does not keep any spaces. It instead changes the spaces into w's. How do I keep the spaces for full sentences? Example of what I need- input: how are you, output: elt xob vlr ---- Example of what I get - input:how are you, output: eltwxobwvlr