[SOLVED] Upserting a collection of objects in Mongo in a batch in java using Mongotemplate

Upserting a collection of objects in Mongo in a batch in java using Mongotemplate

I have a list of objects of type MyObject, and I wish to insert an object if its not present in the mongo collection, or update if it does.

MyObject contains multiple fields, but I want to update if fields f1 & f2 are present in the mongo collection, and insert otherwise.

I know that I can do this for a single object using MongoTemplate's upsert method, and can insert a bunch of objects using MongoTemplate's insertAll method, but neither does what I'm trying to do.

What's the best and most efficient way to achieve what I'm trying to do?

Solution

 public <T> void batchUpdate(String collectionName, List<T> documents, Class<T> tClass) {
    BulkOperations bulkOps = mongoTemplate.bulkOps(BulkOperations.BulkMode.UNORDERED, tClass, collectionName);
    for (T document : documents) {
        Document doc = new Document();
        mongoTemplate.getConverter().write(document, doc);
        org.springframework.data.mongodb.core.query.Query  query = new org.springframework
                .data.mongodb.core.query.Query(Criteria.where(UNDERSCORE_ID).is(doc.get(UNDERSCORE_ID)));
        Document updateDoc = new Document();
        updateDoc.append("$set", doc);
        Update update = Update.fromDocument(updateDoc, UNDERSCORE_ID);
        bulkOps.upsert(query, update);
    }
    bulkOps.execute();
}

You can use this code as a reference and modify it based on your requirement of fields to be checked.

You can check the Mongo doc for Bulk.find.update() here :- https://www.mongodb.com/docs/manual/reference/method/Bulk.find.update/