Ktor

1. On the Welcome screen, click New Project.

   Otherwise, go to File | New | Project in the main menu.

2. In the New Project wizard, choose Ktor from the list on the left.

3. On the right pane, you can specify the following settings:

   

   • Name: Specify a project name.

   • Location: Specify a directory for your project.

   • Build System: Choose the desired build system. This can be Gradle with Kotlin or Groovy DSL, or Maven.

   • Website: Specify a domain used to generate a package name.

   • Artifact: This field shows a generated artifact name.

   • Ktor version: Choose the required Ktor version.

   • Engine: Select an engine used to run a server.

   • Configuration in: Choose whether to specify server parameters in code, in a HOCON or Yaml file.

   • Add sample code: Use this option to add sample code for plugins, which will be added on the next page.

4. On the next page, you can choose a set of plugins - building blocks that provide common functionality of a Ktor application, such as authentication, serialization and content encoding, compression, cookie support, and so on.

   

   Click Create and wait until IntelliJ IDEA generates a project and installs the dependencies.

1. Click the gutter icon next to the main function and choose Run 'ApplicationKt'.

   

2. Wait until IntelliJ IDEA runs the application. The Run tool window should show the following message:

   INFO ktor.application - Responding at http://0.0.0.0:8080

   

   This means that the server is ready to accept requests at the http://0.0.0.0:8080 address.

Find routes with Search Everywhere

To find a specific route in your application using Search everywhere, follow the steps below:

1. Press Shift twice to open the search window.

2. Start typing a route name.

   

   To narrow down your search, click the Filter icon on the window toolbar and select URLs.

Navigate between a route and its usages

To navigate between a route and its usages in a project, do one of the following:

• Place the caret at the desired path or URL and press Ctrl+B.

• Keeping Ctrl pressed, hover over the path or URL. When a URL turns into a hyperlink, click it without releasing the key.

• Click the icon next to the path or URL and choose Go to declaration or usages from a popup.

IntelliJ IDEA will show related paths/URLs:

Show routes in the Endpoints tool window

To see all HTTP or WebSocket endpoints defined in your Ktor application, use the Endpoints tool window:

1. Click the icon next to the path and choose Show all endpoints of module from a popup.

   

2. In the invoked Endpoints tool window, you can see all the routes defined in your application.

   

   If a Ktor server is running, you can make a request using the HTTP Client to see a response immediately or open it in the editor.

   

   On the OpenAPI tab, you can see an OpenAPI specification for this route.

Generate code for plugins

IntelliJ IDEA allows you to generate code for Ktor plugins using the code completion popup:

1. Place the caret inside a module, start typing install and then choose the desired plugin from the list.

   

2. Press Enter. IntelliJ IDEA generates code for the selected plugin and adds the required dependencies to the build script.

   

Generate HttpClient

IntelliJ IDEA provides the ability to quickly add the HttpClient to your project:

• Start typing ktor-client, choose this action from the list, and press Enter.

  

  IntelliJ IDEA creates the HttpClient instance and adds the required client dependencies to the build script.

Create tests

IntelliJ IDEA allows you to generate tests for modules, groups of routes, or individual routes. This functionality is supported for both HTTP and WebSocket endpoints. To generate tests, follow the steps below:

1. Place the caret at the desired module or route, press Alt+Enter, and choose one of the following actions:

   • Create test for Ktor module

   • Create test for Ktor routes

   • Create test for Ktor route

   

   

   

2. In the invoked dialog, you can specify a test class name, choose the desired routes, and edit individual test names.

   

   Click OK.

3. IntelliJ IDEA will create a test class containing tests requests for the selected routes.

   

   You can learn how to test a Ktor server from Testing.

Complete route names

IntelliJ IDEA allows you to complete the names of routes:

• Place the caret at the parameter that accepts a URL and press Ctrl+Space. The editor will show you the available routes.

  

Complete configuration properties

If your project stores configuration in a YAML file, you can use autocompletion for property names:

• Place the caret at any place in the configuration file and press Ctrl+Space. The editor will show you all configuration properties available for this group.

  

Rename routes

In IntelliJ IDEA, you can use rename refactoring to rename routes:

1. Place the caret at the route name and press Shift+F6.

2. Specify a new route name and click Refactor.

   

Extract an application module

To extract code placed inside embeddedServer to a separate application module, follow the steps below:

1. Place the caret at the embeddedServer function call and press Alt+Enter.

2. Choose Extract Application module from the current embeddedServer block and press Enter.

3. In the invoked dialog, specify a module name and click Extract. IntelliJ IDEA creates an extension function on the Application class and passes a reference to this function as the module parameter, for example:

   fun main() { embeddedServer(Netty, port = 8080) { routing { get("/") { call.respondText("Hello, world!") } } }.start(wait = true) }

   fun main() { embeddedServer(Netty, port = 8080, module = Application::module).start(wait = true) } fun Application.module() { routing { get("/") { call.respondText("Hello, world!") } } }

Generate an OpenAPI specification

To generate an OpenAPI specification for a Ktor application, follow the steps below:

1. Place the caret at the embeddedServer function call and press Alt+Enter.

2. Select Generate OpenAPI documentation for current module from the popup and press Enter.

   

3. Wait until IntelliJ IDEA will generate an OpenAPI specification in application resources by the following path: resources/openapi/documentation.yaml.

   

Preview OpenAPI and test your application

You can preview an OpenAPI specification using the integrated Swagger UI as described in Preview an OpenAPI specification. The generated Swagger UI can be used to test your application's endpoints as follows:

1. Run the application.

2. Expand the desired endpoint in the preview and make a request.

1. Place the caret at the desired path, press Alt+Enter, and choose Generate request in HTTP Client.

   

2. In the opened file, adjust request parameters.

   

3. Click in the gutter to make a request.

   

Migrate a project

In IntelliJ IDEA, you can migrate your Ktor project to the latest version in one of the following ways:

• When opening a project that uses a previous Ktor version, IntelliJ IDEA suggests you migrate this project or a specific module to the latest version.

  

  You can migrate a project/module or click Actions to configure a migration level or cancel migration and disable this popup.

• Press Ctrl+Shift+A, find the Migrate Ktor to Latest Version action, and press Enter.

Configure a migration level

• To configure a migration level or disable migrations at all, use a corresponding option on the Settings | Languages & Frameworks | Ktor page.