Convert POJO to/from BSON

Background:

POJO stands for Plain Old Java Objects. It denoted a Java object which does not follow any of the major Java object models, conventions, or frameworks (wikipedia).

BSON is the binary encoding of JSON-like documents that MongoDB uses when storing documents in collections (source).

Problem Definition:

While I am using Spring Boot framework to connect to MongoDb instance, I need to serialize the POJO to BSON, and deserialize from BSON to POJO. As legacy ways, users need to write explicit classes to connect the two foreign lands. We are searching for a more practical, comprehensive and intelligent way to do such boilerplate codes.

Solutions:

CodecRegistry pojoCodecRegistry = fromRegistries(
    MongoClientSettings.getDefaultCodecRegistry(),
    fromProviders(
        PojoCodecProvider.builder().automatic(true).build()
    )
);

We can create a custom CodecRegistry and provide it when we connect to the MongoDb instance. It will provide the out-of-box experience to translate POJO to/from BSON. Based on the documentation, it will work on most useful Java non-premitive data types including String, Integer, Double..., upon which your own object classes are built.

Side Notes:

• Some data types (e.g. UUID) may need extra Codec configurations. Their configurations should be provided above getDefaultCodecRegistry.

CodecRegistry pojoCodecRegistry = fromRegistries(
    fromCodecs(new UuidCodec(UuidRepresentation.STANDARD)),
    // and any other configurations...
    MongoClientSettings.getDefaultCodecRegistry(),
    fromProviders(
        PojoCodecProvider.builder().automatic(true).build()
    )
);

• By default the PojoCodec will search for the default empty public constructor in the POJO. It also relies on the public setters and getters. The default behavior may limit the design styles of your POJO. E.g. No final fields.