Upload files to Google Drive with Kotlin

Lots of projects nowadays are using Google API. In this post, we will take a look at how to upload files to your Google Drive with Kotlin.

There are several available HTTP clients on JVM, however, most of them have a developer’s experience targeted on Java.

In our examples, we’re going to use kohttp, an idiomatic Kotlin DSL HTTP client.

At first, you need to add kohttp to your project dependencies

implementation(group = "io.github.rybalkinsd", name = "kohttp", version = "0.10.0")

Gradle Groovy DSL and Maven are also supported.

According to Drive API v3 a simple HTTP upload request should look like

POST https://www.googleapis.com/upload/drive/v3/files?uploadType=media 
HTTP/1.1
Content-Type: [FILE_CONTENT_TYPE]
Content-Length: [NUMBER_OF_BYTES_IN_FILE]
Authorization: Bearer [YOUR_AUTH_TOKEN]

[FILE_DATA]

Let’s have a look at how to create such a request with kohttp. As described in request spec, we need a POST request.

The only issue now is to get valid token for your request. Fortunately, here is a great article explaining the process it step by step.

httpPost is a DSL function fully featured with code completion inside your IDE. It allows adding headers, parameters, and cookies, so it will be pretty easy to add metadata to your upload request.