Simple code to format person name

Its a sample method about how to format a person's name. Suppose if name of the person is Fernando F Torres, with Torres being the last name, then result of code run would be Torres, Fernando F.

public class SimpleNameFormat {

   public static void main(String[] args){
    
    
    String name = formatPersonName("Torres", "Fernando", "F");
    System.out.println(name);
    
   }
 
   public static String formatPersonName(String lastName, String firstName, String middleName) {
      StringBuffer result = new StringBuffer("");
      boolean breakFlag = false;
      String subStr = "";

      if (lastName != null)
        lastName = lastName.trim();
      else
        lastName = "";
      if (firstName != null)
        firstName = firstName.trim();
      else
        firstName = "";
      if (middleName != null)
        middleName = middleName.trim();
      else
        middleName = "";

      if (lastName.equals("")) {
        breakFlag = true;
      } else {
        result.append(lastName);
        subStr = ", ";
      }
      if (firstName.equals("")) {
        if (breakFlag == true) {
          return result.toString();
        }
      } else {
        result.append(subStr);
        subStr = " ";
        result.append(firstName);
      }
      if (! (middleName.equals(""))) {
        result.append(subStr);
        result.append(middleName);
      }
      return result.toString();
    }

}