Based one some conditions, I have read data from MongoDB and creating a List<Document>
with resultset.
List<Document> documentList = new ArrayList<Document>();
Sample Record Looks like:
documentList: [
Document{
{ _id=5975ff00a213745b5e1a8ed9,
u_id=,
visblty = 1,
c_id=5975ff00a213745b5e1a8ed8,
batchid=null,
pdate=Tue Jul 11 17:52:25 IST 2017,
locale=en_US,
subject = "Document2"
} },
Document{
{ _id=597608aba213742554f537a6,
u_id=,
visblty = 1,
c_id=597608aba213742554f537a3,
batchid=null,
pdate=Fri Jul 28 01:26:22 IST 2017,
locale=en_US,
subject = "Document2"
} }
]
Using this documentList, again i am filtering using some conditions and then I need to sort the filter record based on some conditions (which I will get in request).
List<Document> outList = documentList.stream()
.filter(d -> d.getInteger("visblty") == 1
&& (!StringUtils.isEmpty(req.pdate())? (d.getDate(CommonConstants.PDATE).after(afterDate)): true)
&& (!StringUtils.isEmpty(req.pdate())? (d.getDate(CommonConstants.PDATE).before(beforeDate)): true)
.sorted().skip(4).limit()
.collect(Collectors.toList());
Not sure how to sorted (Dynamically needs to change the sorting order based on input, it looks like "pdate by DESC
" or "subject by ASC"
)
Like: "order by pdate DESC" or "order by pdate ASC"" or "order by subject DESC"
How to sort using Comparator object of Document class.
Note: I have tried couple of method which was suggested by the folks, but I didn't get any luck yet. Thank you in advance!
You can use group comparator and parallel stream as follows:
List<Document> outList = documentList.stream()
.filter(....)
.sorted(Comparator.comparing(Document::getPdate)
.thenComparing(Document::getSubject))
.parallel();