1 files changed, 52 insertions, 0 deletions
diff --git a/formats/hocon/src/main/kotlin/kotlinx/serialization/hocon/serializers/JavaDurationSerializer.kt b/formats/hocon/src/main/kotlin/kotlinx/serialization/hocon/serializers/JavaDurationSerializer.kt
new file mode 100644
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+++ b/formats/hocon/src/main/kotlin/kotlinx/serialization/hocon/serializers/JavaDurationSerializer.kt
@@ -0,0 +1,52 @@
+package kotlinx.serialization.hocon.serializers
+
+import java.time.Duration as JDuration
+import kotlin.time.*
+import kotlinx.serialization.*
+import kotlinx.serialization.ExperimentalSerializationApi
+import kotlinx.serialization.descriptors.*
+import kotlinx.serialization.encoding.*
+import kotlinx.serialization.hocon.*
+import kotlinx.serialization.hocon.internal.*
+
+/**
+ * Serializer for [java.time.Duration].
+ * All possible Hocon duration formats [https://github.com/lightbend/config/blob/main/HOCON.md#duration-format] are accepted for decoding.
+ * During encoding, the serializer emits values using time unit short names: d, h, m, s, ms, us, ns.
+ * The largest integer time unit is encoded.
+ * Example:
+ *      120.seconds -> 2 m;
+ *      121.seconds -> 121 s;
+ *      120.minutes -> 2 h;
+ *      122.minutes -> 122 m;
+ *      24.hours -> 1 d.
+ * When encoding, there is a conversion to [kotlin.time.Duration].
+ * All restrictions on the maximum and minimum duration are specified in [kotlin.time.Duration].
+ * Usage example:
+ * ```
+ * @Serializable
+ * data class ExampleDuration(
+ *  @Serializable(JDurationSerializer::class)
+ *   val duration: java.time.Duration
+ * )
+ * val config = ConfigFactory.parseString("duration = 1 day")
+ * val exampleDuration = Hocon.decodeFromConfig(ExampleDuration.serializer(), config)
+ * val newConfig = Hocon.encodeToConfig(ExampleDuration.serializer(), exampleDuration)
+ * ```
+ */
+@ExperimentalSerializationApi
+@SuppressAnimalSniffer
+object JavaDurationSerializer : KSerializer<JDuration> {
+
+    override val descriptor: SerialDescriptor =
+        PrimitiveSerialDescriptor("hocon.java.time.Duration", PrimitiveKind.STRING)
+
+    override fun deserialize(decoder: Decoder): JDuration =
+        if (decoder is HoconDecoder) decoder.decodeConfigValue { conf, path -> conf.decodeJavaDuration(path) }
+        else throwUnsupportedFormatException("JavaDurationSerializer")
+
+    override fun serialize(encoder: Encoder, value: JDuration) {
+        if (encoder is HoconEncoder) encoder.encodeString(encodeDuration(value.toKotlinDuration()))
+        else throwUnsupportedFormatException("JavaDurationSerializer")
+    }
+}