kalix.scalasdk.JsonSupport.scala Maven / Gradle / Ivy
/*
* Copyright 2021 Lightbend Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package kalix.scalasdk
import com.google.protobuf.any.{ Any => ScalaPbAny }
import kalix.javasdk.{ JsonSupport => JavaJsonSupport, Kalix }
import com.fasterxml.jackson.databind.ObjectMapper
import com.fasterxml.jackson.module.scala.DefaultScalaModule
import scala.jdk.OptionConverters._
import scala.reflect.ClassTag
object JsonSupport {
getObjectMapper().registerModule(new DefaultScalaModule)
/**
* The Jackson ObjectMapper that is used for encoding and decoding JSON. You may adjust it's configuration, but that
* must only be performed before starting [[Kalix]]
*/
def getObjectMapper(): ObjectMapper = JavaJsonSupport.getObjectMapper
/**
* Encode the given value as JSON using Jackson and put the encoded string as bytes in a protobuf `Any` with the type
* URL `json.kalix.io/[valueClassName]`.
*
* Note that if the serialized Any is published to a pub/sub topic that is consumed by an external service using
* the class name suffix this introduces coupling as the internal class name of this service becomes known to the
* outside of the service (and for example renaming it may break existing consumers). For such cases consider using
* the overload with an explicit name for the JSON type instead.
*
* @see
* [[encodeJson(T, java.lang.String)]]
*/
def encodeJson[T](value: T): ScalaPbAny = ScalaPbAny.fromJavaProto(JavaJsonSupport.encodeJson(value))
/**
* Encode the given value as JSON using Jackson and put the encoded string as bytes in a protobuf Any with the type
* URL `json.kalix.io/[jsonType]`.
*
* @param value
* the object to encode as JSON, must be an instance of a class properly annotated with the needed Jackson
* annotations.
* @param jsonType
* A discriminator making it possible to identify which type of object is in the JSON, useful for example when
* multiple different objects are passed through a pub/sub topic.
* @throws IllegalArgumentException
* if the given value cannot be turned into JSON
*/
def encodeJson[T](value: T, jsonType: String): ScalaPbAny =
ScalaPbAny.fromJavaProto(JavaJsonSupport.encodeJson(value, jsonType))
/**
* Decode the given protobuf `Any` object to an instance of `T` using Jackson. The object must have the JSON string as
* bytes as value and a type URL starting with `json.kalix.io/`.
*
* @param valueClass
* The type of class to deserialize the object to, the class must have the proper Jackson annotations for
* deserialization.
* @return
* The decoded object
* @throws IllegalArgumentException
* if the given value cannot be decoded to a T
*/
def decodeJson[T: ClassTag](any: ScalaPbAny): T =
JavaJsonSupport.decodeJson(implicitly[ClassTag[T]].runtimeClass.asInstanceOf[Class[T]], ScalaPbAny.toJavaProto(any))
/**
* Decode the given protobuf Any to an instance of `T`` using Jackson but only if the suffix of the type URL matches
* the given jsonType.
*
* @return
* An Option containing the successfully decoded value or None if the type suffix does not match.
* @throws IllegalArgumentException
* if the suffix matches but the Any cannot be parsed into a T
*/
def decodeJson[T: ClassTag](jsonType: String, any: ScalaPbAny): Option[T] =
JavaJsonSupport
.decodeJson(implicitly[ClassTag[T]].runtimeClass.asInstanceOf[Class[T]], jsonType, ScalaPbAny.toJavaProto(any))
.toScala
}