Kotlin

Experimental API @since 6.0.0

The instancio-kotlin module provides a Kotlin-native API for creating objects and working with selectors. See Getting Started for dependency information.

It offers the same functionality as the core Java API, enhanced with Kotlin-specific improvements such as reified type parameters and Kotlin property references, which eliminate the need to pass Class objects or type tokens explicitly.

The KInstancio object is the entry point, mirroring the Java Instancio ↗ class:

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// Create a single instance — no Class argument needed
val person: Person = KInstancio.create<Person>()

// Create a generic type — no TypeToken needed
val pairs: List<Pair<String, Long>> = KInstancio.createList<Pair<String, Long>>()

// Use the builder API to customise generated values
val person: Person = KInstancio.of<Person>()
    .generate(KSelect.field(Person::age)) { gen -> gen.ints().range(18, 65) }
    .create()

The KSelect object provides all selector methods available in the Java Select ↗ class, with the addition of Kotlin property reference selectors for both field() and scope():

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// Select a field using a Kotlin property reference
val person: Person = KInstancio.of<Person>()
    .ignore(KSelect.field(Person::address))
    .set(KSelect.allStrings().within(KSelect.scope(Person::homeAddress)), "N/A")
    .create()