thymeleaf comprobar si nulo o vacío
<div th:if= "${searchResults.results != null}">
thymeleaf es la cadena vacía
<p th:text="${#strings.isEmpty(string)}"></p>
<p th:text="${#strings.isEmpty(nullString)}"></p>
<p th:text="${#strings.defaultString(emptyString,'Empty String')}"></p>