Routing

One of the main pieces of a mangoo I/O application is the mapping of request URLs to controller classes and their methods. Whether you are rendering a template, sending JSON or just a HTTP 200 OK, every request has to be mapped. This mapping is done in the Bootstra.java class, which you’ll find in the /src/main/java/app package of your application.

Here is an example of how a routing might look like.

@Override
public void initializeRoutes() {
    // ApplicationController
    Bind.controller(ApplicationController.class).withRoutes(
    	On.get().to("/").respondeWith("index")
	);
}

This example maps a GET request to “/” to the index method of the ApplicationController class. Thus, when you open your browser and open the “/” of your application the index method in the ApplicationController class will be called.

You can use the following request methods to define your mappings

GET
POST
OPTIONS
PUT
HEAD
DELETE
PATCH

The underlying Undertow server handles all request by using non-blocking I/O. However, there might be situations where you need a long running request. To allow blocking in a request, simply at the blocking attribute to your request mapping.

@Override
public void initializeRoutes() {
    // ApplicationController
    Bind.controller(ApplicationController.class).withRoutes(
    	On.get().to("/").respondeWith("index").withNonBlocking()
	);
}

Static files

If you want to serve static files (e.g. assets) you can map those files from your routes.yaml. You can map either a specific file or a complete folder and all its sub-content.

Bind.pathResource().to("/assets/");
Bind.fileResource().to("/robots.txt");

The file or path mapping is bound to the src/main/resources/files folder in your application. The above mappings would server the following files accordingly.

/src/main/resources/files/robots.txt
/src/main/resources/files/assets/

Server Sent Events and WebSocket

Mappings for Server-Sent Events and WebSockets are also defined in the routes.yaml. As the Server-Sent Event is a uni-directional protocol, it does not have a controller it needs mapping to. You would map a Server-Sent Event as follows

Bind.serverSentEvent().to("/mysse");

As a WebSocket comes with a pre-defined interface, you just need to add you implementing class

Bind.webSocket().onController(WebSocketController.class).to("/websocket");

There might be situations where your Server-Sent Events and/or WebSockets are only available for authenticated users. If this is the case, you can simply add the authentication attribute to your mappings.

Bind.serverSentEvent().to("/sseauth").withAuthentication();

This will require an authentication cookie in the request to the Server-Sent Event or WebSocket, which is based on the build-in authentication mechanism. If the request does not have such a cookie, the Server-Sent Event or WebSocket connection will be rejected.

Check the page for Server-Sent Events and WebSocket on how to handled the SSE and WSS requests.