create-multipart-upload.groovy

// route handler (Bootstrap.groovy):
post "/oci/upload-create", { req, res ->
    def objectName = req.queryParams("objectName")
    def contentType = req.queryParams("contentType")
    return JsonOutput.toJson( objectService.createMultipartUpload(objectName, contentType) )
}

// service method (ObjectService.groovy):
def createMultipartUpload(objectName, contentType="application/octet-stream") {
    CreateMultipartUploadDetails createMultipartUploadDetails = CreateMultipartUploadDetails.builder()
            .object(objectName)
            .contentType(contentType)
            .build()
    CreateMultipartUploadRequest createMultipartUploadRequest = CreateMultipartUploadRequest.builder()
            .namespaceName(namespaceName)
            .bucketName(bucketName)
            .createMultipartUploadDetails(createMultipartUploadDetails)
            .build()
    return objectClient.createMultipartUpload(createMultipartUploadRequest)
}