1 files changed, 46 insertions, 0 deletions
diff --git a/formats/json-tests/jvmTest/src/kotlinx/serialization/SerializeJavaClassTest.kt b/formats/json-tests/jvmTest/src/kotlinx/serialization/SerializeJavaClassTest.kt
new file mode 100644
index 00000000..a2f900d0
--- /dev/null
+++ b/formats/json-tests/jvmTest/src/kotlinx/serialization/SerializeJavaClassTest.kt
@@ -0,0 +1,46 @@
+/*
+ * Copyright 2017-2020 JetBrains s.r.o. Use of this source code is governed by the Apache 2.0 license.
+ */
+
+package kotlinx.serialization
+
+import kotlinx.serialization.descriptors.*
+import kotlinx.serialization.encoding.*
+import kotlinx.serialization.json.Json
+import org.junit.Test
+import java.text.DateFormat
+import java.text.SimpleDateFormat
+import java.util.*
+import kotlin.test.assertEquals
+
+object DateSerializer : KSerializer<Date> {
+    override val descriptor: SerialDescriptor = PrimitiveSerialDescriptor("java.util.Date", PrimitiveKind.STRING)
+
+    // Consider wrapping in ThreadLocal if serialization may happen in multiple threads
+    private val df: DateFormat = SimpleDateFormat("dd/MM/yyyy HH:mm:ss.SSS").apply {
+        timeZone = TimeZone.getTimeZone("GMT+2")
+    }
+
+    override fun serialize(encoder: Encoder, value: Date) {
+        encoder.encodeString(df.format(value))
+    }
+
+    override fun deserialize(decoder: Decoder): Date {
+        return df.parse(decoder.decodeString())
+    }
+}
+
+@Serializable
+data class ClassWithDate(@Serializable(with = DateSerializer::class) val date: Date)
+
+class SerializeJavaClassTest {
+    @Test
+    fun serializeToStringAndRestore() {
+        // Thursday, 4 October 2018 09:00:00 GMT+02:00 — KotlinConf 2018 Keynote
+        val date = ClassWithDate(Date(1538636400000L))
+        val s = Json.encodeToString(date)
+        assertEquals("""{"date":"04/10/2018 09:00:00.000"}""", s)
+        val date2 = Json.decodeFromString(ClassWithDate.serializer(), s)
+        assertEquals(date, date2)
+    }
+}