LinkedHashMap

If you have a HashMap in a particular order and want to make sure it gets maintained, use LinkedHashMap.


// LinkedHashMap remembers the order in which the items are added to the list,
// which preserves the sorting coming from the db
Map<String, List<TopSellerDO>> topSellersByCategoryMap = new LinkedHashMap<String, List<TopSellerDO>>();


JSTL code to iterate over a Map

Helpful snippet of JSTL code to iterate over a

Map<String, List<SomeDO>>

<c:set var="topSellersByCategoryMap" value="${results.topSellersByCategoryMap}"/>

<c:forEach var="entry" items="${topSellersByCategoryMap}">
  Name: ${entry.key}
  Value: ${entry.value}

    <c:forEach var="listitem" items="${entry.value}">
      Item: ${listitem.merchant.domain}
    </c:forEach>
</c:forEach>