java.time.ZonedDateTime not supported in ObjectMapper

Recently I was trying to serialize a Java object into json using ObjectMapper but encountered the following exception

com.fasterxml.jackson.databind.exc.InvalidDefinitionException: Java 8 date/time type `java.time.ZonedDateTime` not supported by default: add Module "com.fasterxml.jackson.datatype:jackson-datatype-jsr310" to enable handling

The reason was that Java time module is not supported by default and it does not work just by adding maven dependency. The following code worked for me.

objectMapper = new ObjectMapper();
objectMapper.registerModule(new JavaTimeModule());
objectMapper.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);

Finding mongo documents with lowercase values in a mongo collection

Recently we were trying to make our mongo DB based application case insensitive and for testing we needed to find all document containing lowercase alphabets in a filed called "sku". The following query was able to do the work.

{"$expr": {"$ne": ["$sku", {"$toUpper": "$sku"}]}}

Please note that this query does not work on AWS DocumentDB.