The app starts a Thread that uses ServerSocket to allow connections. Each connection is then processed on a separate Thread.
Main components of the app:
The WebServer uses ServerSocket and listens for connections to be made. Once a connection is made it is then delegated to the ClientWorker component.
The ClientWorker parses the input that the connections have. More specifically, it searches for the HTTP method, the endpoint, and the Accept headers. The parsed input (Request) is then sent to the Endpoint handler which returns a Response. Finally, the ClientWorker sends the response to the client connection and returns a ConnectionSnapshot (Request, Response) object to the WebServer.
The EndpointHandler maps the Request to a Response object. It does so by examining the endpoint and the Accept header. The EndpointHandler component supports text/html and application/json Accept headers. Based on the Accept headers it returns a HTML page (HtmlResponse) or JSON (JsonResponse).
This component also supports query parameters. In the case of the /weather endpoint, the EndpointHandler searches for the location param. The location param is then used for an API call to Open-Meteo.com, then a Response is returned as stated above. Note: Even though the app makes API requests to obtain the weather data, only weather?location=sofia is currently supported.
Install the app on your device and start the WebServer by pressing the start button.
On the host device, the WebServer could be reached through the browser on the following URL localhost:8080/home. Other devices would need the Local IP address of the host, for example: 192.168.0.103:8080/home.
As mentioned above, the WebServer can return JSON responses. The easiest way to test this is to use an app like Postman. Make sure that the Accept header has the following value application/json. A ready-to-be-used Postman collection can be downloaded from here.
Besides the default endpoints /home, about, and /weather it is possible to define custom endpoints. This can be done through the Endpoints screen.
