Kotlinx.deserialization example

build.gradle

buildscript {
    ext.kotlin_version = '1.3.21'
    repositories {
        jcenter()
    }

    dependencies {
        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:1.3.21"
        classpath "org.jetbrains.kotlin:kotlin-serialization:1.3.21"
    }
}

plugins {
    id 'org.jetbrains.kotlin.jvm' version '1.3.21'
}

apply plugin: 'kotlin' // or 'kotlin-multiplatform' for multiplatform projects
apply plugin: 'kotlinx-serialization'


group 'io.quantus'
version '1.0-SNAPSHOT'

repositories {
    mavenCentral()
    jcenter()
    maven { url "https://kotlin.bintray.com/kotlinx" }
}

dependencies {
    implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk8"
    implementation "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
    implementation "org.jetbrains.kotlinx:kotlinx-serialization-runtime:0.10.0"
}

compileKotlin {
    kotlinOptions.jvmTarget = "1.8"
}
compileTestKotlin {
    kotlinOptions.jvmTarget = "1.8"
}

main.kt

import kotlinx.serialization.SerialName
import kotlinx.serialization.Serializable
import kotlinx.serialization.Transient
import kotlinx.serialization.json.Json


val json = """
    {
      "History":
      [
        {"Added": 2000}
      ]
    }
"""

@Serializable
data class History(
    @SerialName("Added")
    val addedTimeInSeconds : Long
) {

    init {
        println("### in init $addedTimeInSeconds")
    }

    @Transient
    val addedTimeInMillis : Long = addedTimeInSeconds * 1000
}

@Serializable
data class HistoryResponse(
    @SerialName("History")
    val historyList: List<History>
)


fun main() {
    val response = Json.parse(HistoryResponse.serializer(), json)

    println(response)

    println("added time in millis ${response.historyList.first().addedTimeInMillis}")
}

output

### in init 2000
HistoryResponse(historyList=[History(addedTimeInSeconds=2000)])
added time in millis 2000000