Server

[LeanderK]

This pull-request adds full support for the upcoming cloud-infrastructure

please visit intellimate/Izou#52 for further information about the motivation.

This pull request introduces the package server to the SDK which contains an simple rest-compatible server-framework used for answering requests from the router.

package server:

• BadRequestException: this exception can be thrown inside the routing-handlers to signal an BadRequest (400)
• DefaultHandler: the default implementation of the Handler-interface which checks for the correct method on handle
• Handler: the handler is a simple functional interface called by Route when the route matches, it can either return an response or declare itself for responsible
• HandlerHelper: contains various utility methods for handling requests
• InternalServerErrorException: his exception can be thrown inside the routing-handlers to signal an InternalServerError (500)
• Method: this enum represents the different commonly used methods for http-requests
• NotFoundException: this exception can be thrown inside the routing-handlers to signal an NotFound (404)
• Request: this class implements the Request interface from Izou and extends it with various useful functionality
• Response: an Response implementation and various useful methods
• Route: this class represents a single route in the Router, e.g. /static
• Router: this class gets called in the sdk when an request from the server was made. The Add-on can specify multiple routes and error-handlers and the router processes the request accordingly.
• SDKRouter: the Router for the SDK, it also serves as an example-implementation. It servers an static html file on index and provides an html file used to render the properties-files for other addons on /template/properties
• PropertiesRouter: the default Router for addons. It forwards calls on / oder /index.html to /template/properties of the SDK with some query parameters to populate the template. It also has an endpoint for the actual properties-file and a (optional) markdown description of it which will be rendered by /template/properties from the SDK.

package util:

• ResourceUser: clarified TODO

package add-on

• AddOn: updated to the new interface wich includes the handling of requests and links it to the default implementation (PropertiesRouter)

package sdk:
changes:

• Context: reflected changes in the Interface specified in Izou

added:

• AddOnImpl: the SDK now needs an AddonImplementation to serve the http-requests.

some non-java changes:
added the necessary html-files to the resources folder and updated the pom.xml

[LeanderK]

there are some small things to fix, but it is largely done

[LeanderK]

mostly tested and done