[Kotlin]] add support for binary response (#9284)

* Support File responses for Kotlin client

* Regen samples

* Reset version

* Fix file class check

* Add imports

* use Files.createTempFile instead

* better tmp file naming

Co-authored-by: Mischa Spiegelmock <me@mish.dev>

samples/client/petstore/kotlin-json-request-string/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -13,7 +13,10 @@ import okhttp3.Request
 import okhttp3.Headers
 import okhttp3.MultipartBody
 import java.io.File
+import java.io.BufferedWriter
+import java.io.FileWriter
 import java.net.URLConnection
+import java.nio.file.Files
 import java.util.Date
 import java.time.LocalDate
 import java.time.LocalDateTime
@@ -114,6 +117,15 @@ open class ApiClient(val baseUrl: String) {
         if (bodyContent.isEmpty()) {
             return null
         }
+        if (T::class.java == File::class.java) {
+            // return tempfile
+            val f = Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            f.deleteOnExit()
+            val out = BufferedWriter(FileWriter(f))
+            out.write(bodyContent)
+            out.close()
+            return f as T
+        }
         return when(mediaType) {
             JsonMediaType -> Serializer.moshi.adapter(T::class.java).fromJson(bodyContent)
             else ->  throw UnsupportedOperationException("responseBody currently only supports JSON body.")