CODEWITHSUNDEEP
javamongodbmongodb-java
user837208
user837208

Reputation: 2577

How to query documents using "_id" field in Java mongodb driver?

I am trying to find documents in MongoDB by searching on "_id" key. My document looks like this-

{
  "_id" : ObjectId("4f693d40e4b04cde19f17205"),
  "hostname" : "hostnameGoesHere",
  "OSType" : "OSTypeGoesHere"
}

I am trying to search this document as- 

ObjectId id= new ObjectId("4f693d40e4b04cde19f17205");        
BasicDBObject obj = new BasicDBObject();        
obj.append("_id", id);        
BasicDBObject query = new BasicDBObject();        
query.putAll(query);

But I get below error- 

error: reference to putAll is ambiguous, both method putAll(Map) in BasicBSONObject and method putAll(BSONObject) in BasicBSONObject match
        query.putAll(query);

The append method of BasicDBObject supports (String Key, Value) and if I pass "_id" as String to this method, no documents are matched.

So my question is how do I pass "_id"?

Upvotes: 50

Views: 92717

Answers (8)

Michael
Michael

Reputation: 1183

Don't forget to add the collectionName parameter if your class and collectionName don't match. I landed on this question because my _id query wasn't working even though it looked good at first blush.

Upvotes: 0

Giovani Meza
Giovani Meza

Reputation: 1

I found a way around, with a little bit more of code, requires a string representing the id to be found passed as argument.

import com.mongodb.client.MongoDatabase;
import com.mongodb.client.MongoClient;
import com.mongodb.client.MongoClients;
import com.mongodb.client.MongoCollection;
import com.mongodb.client.model.Filters;
import org.bson.conversions.Bson;
import org.bson.Document;
import org.bson.types.ObjectId;   

[...]

public static void findCustomerById(String id) {
    try (MongoClient mongoClient = MongoClients.create("mongodb://localhost:27017")) {
        MongoDatabase database = mongoClient.getDatabase("database_name");
        Bson filter = Filters.eq("_id", new ObjectId(id));
        MongoCollection<Document> collection = database.getCollection("customer");

        //Tries to find the document
        Document doc = collection. Find(filter).first();
        //prints the document
        System.out.println(doc.toJson());
    } catch (Exception e) {
        System.out.println("Error finding document");
        System.out.println("Error in: " + e.getMessage());
        e.printStackTrace();
    }

Upvotes: 0

user11006286
user11006286

Reputation:

The more simple way to do this is:

Bson filter = Filters.eq("_id", new ObjectId("4f693d40e4b04cde19f17205"));
mongoConfig.getMongoTemplate().getCollection("myCollection").find(filter);

Reference here: https://www.baeldung.com/mongodb-query-documents-id

Upvotes: 2

Srushti Maladkar
Srushti Maladkar

Reputation: 1

You can try this snippet:

ObjectId id= new ObjectId("4f693d40e4b04cde19f17205");        
BasicDBObject obj = new BasicDBObject();        
obj.append("_id", id);        
BasicDBObject query = new BasicDBObject();        
query.putAll((BSONObject)obj);

Upvotes: -2

bogolyandras
bogolyandras

Reputation: 436

For those who are seeking a more up to date method, especially with 3.4:

import com.mongodb.client.MongoCollection;
import com.mongodb.client.MongoDatabase;
import org.bson.Document;
import org.bson.types.ObjectId;

import static com.mongodb.client.model.Filters.eq;

//......
MongoCollection<Document> myCollection = database.getCollection("myCollection");
Document document = myCollection.find(eq("_id", new ObjectId("4f693d40e4b04cde19f17205"))).first();
if (document == null) {
    //Document does not exist
} else {
    //We found the document
}

Upvotes: 34

Chris
Chris

Reputation: 737

Not sure if others might be searching for answers on this topic, but here is the easiest way to search for a MongoDB record based on "_id". The MongoDB documentation is not updated and still shows ObjectId as being part of the com.mongodb package (it also generally does not give a lot of information on searching by ObjectId).

import org.bson.types.ObjectId;

public DBObject findDocumentById(String id) {

    BasicDBObject query = new BasicDBObject();
    query.put("_id", new ObjectId(id));

    DBObject dbObj = collection.findOne(query);
    return dbObj;
}

Upvotes: 71

user837208
user837208

Reputation: 2577

Solved it by using query as- 

query.putAll((BSONObject)query);

Upvotes: 1

Nifras Nipy
Nifras Nipy

Reputation: 101

You can do this

 ObjectId id= new ObjectId("4f693d40e4b04cde19f17205");        
    BasicDBObject obj = new BasicDBObject();        
    obj.append("_id", id);        
    BasicDBObject query = new BasicDBObject();        
    query.putAll((BSONObject)query);

Upvotes: 6

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