This Java class enables students working in BlueJ to submit solutions to DOMjudge.
See also the Dockerized DOMjudge setup.
When the student has created a Java solution with a public static void main(String[] args)
method suitable for the DOMjudge problem definition, the static submit()
method is called on the Submit class to submit all *.java files to DOMjudge.
The first time a problem is submitted, the student must pass to submit()
the problem ID and their username and password for DOMjudge.
On subsequent submissions of the same problem, submit() can be invoked without arguments
to reuse the previous credentials.
The submit() method will poll DOMjudge while waiting for the problem to be judged.
Although third-party Java classes such as the Apache HttpClient
would make implementing Submit a breeze,
the current implementation uses only the HttpURLConnection facilities
in the Java standard library.
The Submit client makes the following HTTP requests:
- POST to
/public/login.phpto enable later polling for the judging result. If an HTTP error (status code ≥ 400) is returned, this is presented to the student as "Wrong username of password". - POST to
/api/submissions, using HTTP Basic Auth for authentication (same as the official DOMjudge client). - GET
/team/submission_details.php?id=id repeatedly until the response doesn't contain "Submission not found" (i.e. not compiled yet) or<span class="sol sol_queued">(i.e. compiled but not judged yet).
When making HTTP POSTs, the POST payload is written directly without using any HTTP helpers, since the Java standard library does not know how to construct HTTP POST data.
The student's credentials are stored in the file submit_data.txt
which also contains a helpful description of what the file is.