Iam stuck in an endless loop, cannot find why...

public class Game{
  public static final int MAX_MISSES = 7;
 private String answer;
 private String hits;
  private String misses;

  public Game (String answer){
    this.answer = answer;
    hits ="";
    misses="";
  }
  public boolean applyGuess(char letter){
    boolean isHit = answer.indexOf(letter) !=-1;
    if(isHit){
      hits+= letter;
    }else {
      misses+=letter;
    }return isHit;
  }
  public int getRemainingTries(){
    return MAX_MISSES - misses.length();
  }
   public String getCurrentProgress(){
     String progress ="";

     for ( char letter : answer.toCharArray()){
       char display = '-';
       if (hits.indexOf(letter) !=-1){
         display = letter;
       }
       progress += display;
     }
     return progress;

  }
}


public class Hangman {

  public static void main(String[] args) {
  Game game = new Game("treehouse");
  Prompter prompter = new Prompter(game);

    while (game.getRemainingTries() >0){

  prompter.displayProgress();
  prompter.promptForGuess();
    }

  }
}


import java.util.Scanner;

public class Prompter{
  private Game game;

  public Prompter(Game game){
    this.game=game;
  }
  public boolean promptForGuess(){
    Scanner scanner = new Scanner(System.in);
    System.out.print("Enter a letter  ");
    String guessInput = scanner.nextLine();
    char guess = guessInput.charAt(0);
    return game.applyGuess(guess);
  }
  public void displayProgress(){
    System.out.printf("You have %d tries, left to solve  %s%n",
                      game.getRemainingTries(),
                      game.getCurrentProgress());
  }
}