CODEWITHSUNDEEP
javamongodbjava-8streamjava-stream
Bharathiraja S
Bharathiraja S

Reputation: 699

How to filter Mongo document based on sub-document in Java 8 Stream Filter

Am trying to filter a sub-document.

Sample Record:

[Document{{_id=597608aba213742554f537a6, upp_id=, content_id=597608aba213742554f537a3, idmapping=Document{{ptype=PDF, clientid=12345, normalizedclientid=12345, systeminstanceid=, sourceschemaname=, platforminternalid=0987654321}}, batchid=null, locale=en_US}}]

I need to filter using idmapping.ptype = PDF

MongoCursor<Document> cursor = mailboxitemCollection.find(whereClause).iterator();
List<Document> documentList = new ArrayList<Document>();

while (cursor.hasNext()) {
  Document object = cursor.next();
  documentList.add(object);
}

 List<Document> outList = documentList.stream()
        .filter(p -> p.getInteger(CommonConstants.VISIBILITY) == 1
            && (!StringUtils.isEmpty(req.ptype())? (p.getString("idmapping.ptype").equalsIgnoreCase(req.ptype())) : true)
            ).parallel().sequential().collect(Collectors.toCollection(ArrayList::new));

System.out.println(outList);
System.out.println(outList.size());

Am getting Null Point exception, am not able to read the sub/embed document from List documentList.

Thank you in advance! Bharathi

Upvotes: 1

Views: 987

Answers (1)

mgyongyosi
mgyongyosi

Reputation: 2677

With the mongo-java-driver you can't access the subdocument's fields directly. You should get the subdocument and after that the field of the subdocument like this:

String platformType =
 ((Document)p.get("idmapping")).getString("ptype");

In your case, change the filter to the following:

.filter(p -> p.getInteger(CommonConstants.VISIBILITY) == 1  && (!StringUtils.isEmpty(req.ptype()) ? (((Document)p.get("idmapping")).getString("ptype").equalsIgnoreCase(req.ptype())) : true))

Upvotes: 5

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