feat(serverbackup): add multi API version support

relates to STACKITSDK-422

Author: rubenhoenle

services/serverbackup/README.md

@@ -1,10 +1,5 @@
 # STACKIT Java SDK for STACKIT Server Backup Management API
 
-- API version: 2.0
-
-API endpoints for Server Backup Operations on STACKIT Servers.
-
-
 This package is part of the STACKIT Java SDK. For additional information, please visit the [GitHub repository](https://github.com/stackitcloud/stackit-sdk-java) of the SDK.
 
 ## Installation from Maven Central (recommended)

services/serverbackup/src/main/java/cloud/stackit/sdk/serverbackup/v1api/ApiCallback.java

@@ -0,0 +1,60 @@
+/*
+ * STACKIT Server Backup Management API
+ * API endpoints for Server Backup Operations on STACKIT Servers.
+ *
+ * The version of the OpenAPI document: 1.0
+ * Contact: support@stackit.de
+ *
+ * NOTE: This class is auto generated by OpenAPI Generator (https://openapi-generator.tech).
+ * https://openapi-generator.tech
+ * Do not edit the class manually.
+ */
+
+package cloud.stackit.sdk.serverbackup.v1api;
+
+import cloud.stackit.sdk.core.exception.ApiException;
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Callback for asynchronous API call.
+ *
+ * @param <T> The return type
+ */
+public interface ApiCallback<T> {
+	/**
+	 * This is called when the API call fails.
+	 *
+	 * @param e The exception causing the failure
+	 * @param statusCode Status code of the response if available, otherwise it would be 0
+	 * @param responseHeaders Headers of the response if available, otherwise it would be null
+	 */
+	void onFailure(ApiException e, int statusCode, Map<String, List<String>> responseHeaders);
+
+	/**
+	 * This is called when the API call succeeded.
+	 *
+	 * @param result The result deserialized from response
+	 * @param statusCode Status code of the response
+	 * @param responseHeaders Headers of the response
+	 */
+	void onSuccess(T result, int statusCode, Map<String, List<String>> responseHeaders);
+
+	/**
+	 * This is called when the API upload processing.
+	 *
+	 * @param bytesWritten bytes Written
+	 * @param contentLength content length of request body
+	 * @param done write end
+	 */
+	void onUploadProgress(long bytesWritten, long contentLength, boolean done);
+
+	/**
+	 * This is called when the API download processing.
+	 *
+	 * @param bytesRead bytes Read
+	 * @param contentLength content length of the response
+	 * @param done Read end
+	 */
+	void onDownloadProgress(long bytesRead, long contentLength, boolean done);
+}