For the record, I predicted this problem would come up... http://www.nabble.com/JSON-output-support-tf1915406.html#a5247622
: We could introduce some new types to tell the output handlers just how : important it is to maintain order, so all named lists don't get : treated the same. : : Example: : class OrderedNamedList extends NamedList {...} Ugh ... please no ... the "List" in "NamedList" is what indicates that order is a factor (it's what distinguishes a NamedList from a hypothetical MultiValueMap") : Using OrderedNamedList, means that it's really important that order be : maintained, and we could a different strategy such as interleaving : keys and values in a single array (or another strategy set by : json.orderednl?) i would much rather see us change any places in the Solr request handlers where order does *not* matter to just use a Map ...then the ResponseWriter could know that order in Maps doesn't matter, but order in NamedLists do. -Hoss