[Kotlin][Client] replace java.nio.* to avoid crash on Android API 25 and bellow (#12529)

* [Kotlin][Client] replace java.nio.* to avoid crash on Android API 25 and bellow

* [Kotlin][Client] update sample projects

* [Kotlin][Client] update sample projects

modules/openapi-generator/src/main/resources/kotlin-client/libraries/jvm-okhttp/infrastructure/ApiClient.kt.mustache

@@ -206,22 +206,26 @@ import com.squareup.moshi.adapter
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             {{^supportAndroidApiLevel25AndBelow}}
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.{{packageName}}", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.{{packageName}}", null).toFile()
             {{/supportAndroidApiLevel25AndBelow}}
             {{#supportAndroidApiLevel25AndBelow}}
-            val f = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val tempFile = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                 java.nio.file.Files.createTempFile("tmp.net.medicineone.teleconsultationandroid.openapi.openapicommon", null).toFile()
             } else {
                 @Suppress("DEPRECATION")
                 createTempFile("tmp.net.medicineone.teleconsultationandroid.openapi.openapicommon", null)
             }
             {{/supportAndroidApiLevel25AndBelow}}
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-array-simple-string-jvm-okhttp3/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -116,12 +116,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-array-simple-string-jvm-okhttp4/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-bigdecimal-default-okhttp4/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-default-values-jvm-okhttp3/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -116,12 +116,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-default-values-jvm-okhttp4/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-enum-default-value/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-gson/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -117,12 +117,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-jackson/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -117,12 +117,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

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

@@ -119,16 +119,20 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
-            val f = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            val tempFile = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
                 java.nio.file.Files.createTempFile("tmp.net.medicineone.teleconsultationandroid.openapi.openapicommon", null).toFile()
             } else {
                 @Suppress("DEPRECATION")
                 createTempFile("tmp.net.medicineone.teleconsultationandroid.openapi.openapicommon", null)
             }
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-jvm-okhttp4-coroutines/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -120,12 +120,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-modelMutable/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-moshi-codegen/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-nonpublic/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ internal open class ApiClient(val baseUrl: String, val client: OkHttpClient = de
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-nullable/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-okhttp3/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -116,12 +116,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

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

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-threetenbp/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin-uppercase-enum/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {

samples/client/petstore/kotlin/src/main/kotlin/org/openapitools/client/infrastructure/ApiClient.kt

@@ -118,12 +118,16 @@ open class ApiClient(val baseUrl: String, val client: OkHttpClient = defaultClie
             return null
         }
         if (T::class.java == File::class.java) {
-            // return tempfile
+            // return tempFile
             // Attention: if you are developing an android app that supports API Level 25 and bellow, please check flag supportAndroidApiLevel25AndBelow in https://openapi-generator.tech/docs/generators/kotlin#config-options
-            val f = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
+            val tempFile = java.nio.file.Files.createTempFile("tmp.org.openapitools.client", null).toFile()
-            f.deleteOnExit()
+            tempFile.deleteOnExit()
-            body.byteStream().use { java.nio.file.Files.copy(it, f.toPath(), java.nio.file.StandardCopyOption.REPLACE_EXISTING) }
+            body.byteStream().use { inputStream ->
-            return f as T
+                tempFile.outputStream().use { tempFileOutputStream ->
+                    inputStream.copyTo(tempFileOutputStream)
+                }
+            }
+            return tempFile as T
         }
         val bodyContent = body.string()
         if (bodyContent.isEmpty()) {