Freundlicher Freundlicher - 5 months ago 59
Java Question

MongoDB java-driver-3.2.2 count results from find()-method

I am trying to count the results of a

find()
method, but it doesn´t work. I am using the
mongodb-driver-3.2.2
and
mongodb-driver-core
for JAVA.

This is the code I am using to connect to the MongoDB

MongoClient mongoClient = new MongoClient("localhost", 27017);
MongoDatabase database = mongoClient.getDatabase("database_name");
MongoCollection<Document> collection = database.getCollection("collection_name");


I search in the MongoDb with this code:

collection.find(eq("status", 1));


The method ".count()" work only for the whole collection, like this:

long a = collection.count();


But when i try to us it in combination with the
find()
method, it doesn´t work:

long a = collection.find(eq("status", 1)).count();


Error:

The method count() is undefined for the type FindIterable<Document>


So, my solution is:

long a = 0;
FindIterable<Document> results = collection.find(eq("status", 1));
for (Document current : results ) {
a++;
}


I DON´T like this solution. Is there a other solution to count the results?

mtj mtj
Answer

Count is a method on the collection object, not on the FindIterable. It takes the filter as an optional parameter, so to stay in the Filters-world:

collection.count(eq("status", 1));
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