Cookbooks
Kotlin
Chapter 10. Data Formats and Serialization
Working with TOML

Kotlin:
Working with TOML

How to:

To handle TOML in Kotlin, you might use a library like ktoml. First, let’s add the dependency in your build.gradle.kts:

dependencies {
    implementation("com.akuleshov7:ktoml:0.2.5")
}

Now, let’s parse some TOML:

import com.akuleshov7.ktoml.file.TomlFileReader

fun main() {
    val tomlContent = TomlFileReader.readAndParseFile("config.toml")
    
    val databaseConfig = tomlContent.getTable("database")
    val host = databaseConfig.getString("host")
    val port = databaseConfig.getLong("port")

    println("Database Host: $host")
    println("Database Port: $port")
}

Assuming config.toml looks like this:

[database]
host = "localhost"
port = 5432

Sample output would be:

Database Host: localhost
Database Port: 5432

Deep Dive

TOML, cooked up by GitHub co-founder Tom Preston-Werner in 2013, aimed to be more straightforward than YAML and more type-safe than JSON. It’s become a hit, especially with Rust’s Cargo and Go’s module system. Alternatives? YAML’s got more features, JSON translates directly into objects in many coding languages, and there’s always good ol’ XML. As for implementation, ktoml, under Apache 2.0 license, is a pure Kotlin library and doesn’t drag Java libs along, offering DSLs to write TOML too, not just read.

See Also

Working with JSONWorking with XML