Multidimensional list in Thymeleaf (Java) - List<List<Object>> - list

Question

Have anyone of you any suggestion, how to iterate through a multidimensional list in Thymeleaf?
My multidimensional list looks as follow:
#Override
public List<List<PreferredZone>> findZonesByPosition(List<Position> positionList) {
List <PreferredZone> prefZone = new ArrayList<>();
List<List<PreferredZone>> listPrefZone = new ArrayList<>();
long positionId = 0;
for (int i = 0; i < positionList.size(); i++) {
positionId = positionList.get(i).getPositionId();
prefZone = prefZoneDAO.findFilteredZone(positionId);
listPrefZone.add(prefZone);
}
return listPrefZone;
}
In my controller as attribute:
List<List<PreferredZone>> prefZoneList = prefZoneService.findZonesByPosition(positionList);
model.addAllAttributes(prefZoneList);
Finally I try to iterate this two dimensional list in a HTML table:
<table th:each="prefList :#{prefZoneList}" class="table table-striped display hover">
<thead>
<tr>
<th>ISO</th>
<th>Name</th>
<th>Ausschluss</th>
</tr>
</thead>
<!-- Loop für die Daten -->
<tr th:each="row, iterState :${prefList}" class="clickable-row">
<td th:text="${row[__${iterState.index}__]}.zoneIso"></td>
<td th:text="${row[__${iterState.index}__]}.zoneName"></td>
<td style="text-align:center;">
<input type="checkbox" th:value="${${row[__${iterState.index}__]}.zoneId}" id="zone" class="checkbox-round" />
</td>
</tr>
</table>
It doesn't work however. I don't have any other idea how to solve this.
I have to have a multidimensional list, because I have got a table with multiple records and each record contains a button to open a modal window. Each of this windows contains either a HTML table where I have to display the records.
Have you got any suggestion for me?

Answer 1

You have a mistake in #{prefZoneList} and (as noted in comments) in using iterState.index
Try it:
<table th:each="prefList : ${prefZoneList}" class="table table-striped display hover">
<thead>
<tr>
<th>ISO</th>
<th>Name</th>
<th>Ausschluss</th>
</tr>
</thead>
<tr th:each="row : ${prefList}" class="clickable-row">
<td th:text="${row.zoneIso}"></td>
<td th:text="${row.zoneName}"></td>
<td style="text-align:center;">
<input type="checkbox" th:value="${row.zoneId}" id="zone" class="checkbox-round" />
</td>
</tr>
</table>
Syntax #{...} - a message Expressions
iterState.index is the current iteration index, starting with 0, using like ${prefList[__${iterState.index}__].element} where element - filed in prefList.