JarCastingMongoLess
Shapeless based BSON serialization for Mongo Java and Scala Drivers
MongoLess is a simple lib for encoding scala case classes for Mongo Java Driver. You can also use it with Scala mongo driver
#Installation
MonadLess is currently available for Scala 2.12 and Java 8. To install MongoLess just add following line to your sbt file
libraryDependencies += "com.github.a14e" %% "mongoless" % "0.3.01"
Case class to/from bson encoding
Encoding to Bson is quiet simple: just import a14e.bson.auto._ and call asBson. For decoding import a14e.bson.auto._ and call .as[...]. If you want to replace field name with _id use ID wrapper.
Simple example
import a14e.bson._
import a14e.bson.auto._
case class User(id: ID[Int],
name: String,
age: Int)
val exampleUser = User(
id = 1,
name = "some name",
age = 25
)
val bson = exampleUser.asBson
// { "age" : 25, "name" : "some name", "_id" : 1 }
bson.as[User] == exampleUser
// true
Nested and recursive case classes are also supported
Bigger example
import a14e.bson._
import a14e.bson.auto._
case class SampleUser(id: ID[Int],
name: String,
job: Option[Job],
children: Seq[SampleUser])
case class Job(company: String,
salary: Long)
val user = SampleUser(
id = 213,
name = "name",
job = Some(
Job(
company = "some company",
salary = 123
)
),
children = Seq(
SampleUser(
id = 456,
name = "name1",
job = None,
children = Seq.empty
)
)
)
val bson = user.asBson
// { "children" : [{ "children" : [], "name" : "name1", "_id" : 456 }], "job" : { "salary" : { "$numberLong" : "123" }, "company" : "some company" }, "name" : "name", "_id" : 213 }
bson.as[SampleUser] == user
// true
Bson builder
MongoLess also offers PlayJson like builder for bson:
import a14e.bson.Bson
Bson.obj(
"_id" -> 213,
"name" -> "name",
"children" -> Bson.arr(
Bson.obj(
"_id" -> 456,
"name" -> "name1",
"children" -> Bson.arr()
)
)
)
// { "_id" : 213, "name" : "name", "children" : [{ "_id" : 456, "name" : "name1", "children" : [] }] }
Search and Recursive search
MongoLess also supports helpers for search and recursive search. Use \ to search in root and \\ for recursive search of nearest node with expected key
import a14e.bson._
val bson = Bson.obj(
"_id" -> 213,
"name" -> "name",
"children" -> Bson.arr(
Bson.obj(
"_id" -> 456,
"name" -> "name1",
"children" -> Bson.arr(),
"someKey" -> 123
)
)
)
bson \\ "_id"
// Success(BsonInt32{value=213})
(bson \\ "_id").as[Int]
// 213
(bson \ "children" \\ "name").as[String]
// name1
(bson \\ "someKey").as[Int]
// 123
Enum Support
MongoLess also offers limited scala enums support. But enum should be an object and it should not be nested
import a14e.bson._
import a14e.bson.auto._
import a14e.bson.auto.enumUnsafe._
object SizeType extends Enumeration {
type SizeType = Value
val Big = Value("BIG")
val Small = Value("SMALL")
}
import SizeType._
case class Hat(price: Int,
sizeType: SizeType)
val hat = Hat(123, Big)
val bsonHat = hat.asBson
//{ "sizeType" : "BIG", "price" : 123 }
bsonHat.as[Hat] == hat
// true
ADT support
One can build ADT encoders throw BsonEncoder.switch (warning: in example lazy val can produce stack overflow)
trait Shape
case class Circle(r: Double) extends Shape
case class Rectangle(a: Double) extends Shape
import a14e.bson.encoder.BsonEncoder
import a14e.bson._
implicit val shapeEncoder: BsonEncoder[Shape] = {
import a14e.bson.auto._
BsonEncoder.switch[String, Shape]("type")(
"circle" -> BsonEncoder.derived[Circle](),
"rectangle" -> BsonEncoder.derived[Rectangle]()
)
}
Circle(1).asBson // { "r" : 1.0, "type" : "circle" }
Rectangle(1).asBson // { "a" : 1.0, "type" : "rectangle" }
and decoders in same way:
trait Shape
case class Circle(r: Double) extends Shape
case class Rectangle(a: Double) extends Shape
import a14e.bson.decoder.BsonDecoder
import a14e.bson._
implicit val decoder: BsonDecoder[Shape] = {
import a14e.bson.auto._
BsonDecoder.switch[String, Shape]("type")(
"circle" -> BsonDecoder[Circle],
"rectangle" -> BsonDecoder[Rectangle]
)
}
val circleBson = Bson.obj(
"type" -> "circle",
"r" -> 1.0
)
circleBson.as[Shape] // == Circle(1.0)
Known Issues
- import of
a14e.bson.auto._can break encoding of BsonNull
import org.bson.BsonNull
import a14e.bson._
import a14e.bson.auto._
Bson.obj("key" -> new BsonNull()).asBson // == {"key" : {}}
workaround: move move or hide import a14e.bson.auto._
import org.bson.BsonNull
import a14e.bson._
Bson.obj("key" -> new BsonNull()).asBson // == {"key" : null}