@Override
public ProblemAndTestCaseList importExercise(Course course, String exerciseHash)
throws CloudCoderAuthenticationException {
if (course == null || exerciseHash == null) {
throw new IllegalArgumentException();
}
// Make sure a user is authenticated
User user =
ServletUtil.checkClientIsAuthenticated(
getThreadLocalRequest(), GetCoursesAndProblemsServiceImpl.class);
// Find user's registration in the course: if user is not instructor,
// import is not allowed
CourseRegistrationList reg = Database.getInstance().findCourseRegistrations(user, course);
if (!reg.isInstructor()) {
throw new CloudCoderAuthenticationException(
"Only an instructor can import a problem in a course");
}
// Attempt to load the problem from the exercise repository.
ConfigurationSetting repoUrlSetting =
Database.getInstance().getConfigurationSetting(ConfigurationSettingName.PUB_REPOSITORY_URL);
if (repoUrlSetting == null) {
logger.error("Repository URL configuration setting is not set");
return null;
}
// GET the exercise from the repository
HttpGet get = new HttpGet(repoUrlSetting.getValue() + "/exercisedata/" + exerciseHash);
ProblemAndTestCaseList exercise = null;
HttpClient client = new DefaultHttpClient();
try {
HttpResponse response = client.execute(get);
HttpEntity entity = response.getEntity();
ContentType contentType = ContentType.getOrDefault(entity);
Reader reader = new InputStreamReader(entity.getContent(), contentType.getCharset());
exercise = new ProblemAndTestCaseList();
exercise.setTestCaseList(new TestCase[0]);
JSONConversion.readProblemAndTestCaseData(
exercise,
ReflectionFactory.forClass(Problem.class),
ReflectionFactory.forClass(TestCase.class),
reader);
// Set the course id
exercise.getProblem().setCourseId(course.getId());
} catch (IOException e) {
logger.error("Error importing exercise from repository", e);
return null;
} finally {
client.getConnectionManager().shutdown();
}
// Set "when assigned" and "when due" to reasonable default values
long now = System.currentTimeMillis();
exercise.getProblem().setWhenAssigned(now);
exercise.getProblem().setWhenDue(now + 48L * 60L * 60L * 1000L);
// Set problem authorship as IMPORTED
exercise.getProblem().setProblemAuthorship(ProblemAuthorship.IMPORTED);
// For IMPORTED problems, parent_hash is actually the hash of the problem
// itself. If the problem is modified (and the authorship changed
// to IMPORTED_AND_MODIFIED), then the (unchanged) parent_hash value
// really does reflect the "parent" problem.
exercise.getProblem().setParentHash(exerciseHash);
// Store the exercise in the database
exercise = Database.getInstance().storeProblemAndTestCaseList(exercise, course, user);
return exercise;
}
@Override
public ShareExercisesResult submitExercises(
Problem[] problems, String repoUsername, String repoPassword)
throws CloudCoderAuthenticationException {
logger.warn("Sharing " + problems.length + " exercises");
// create the result place holder
ShareExercisesResult result = new ShareExercisesResult(problems.length);
if (problems.length == 0) {
result.failAll("No problems to be shared!");
return result;
}
// Only a course instructor may share an exercise.
User authenticatedUser =
ServletUtil.checkClientIsAuthenticated(
getThreadLocalRequest(), GetCoursesAndProblemsServiceImpl.class);
Course course = new Course();
course.setId(problems[0].getCourseId());
Database.getInstance().reloadModelObject(course);
CourseRegistrationList regList =
Database.getInstance().findCourseRegistrations(authenticatedUser, course);
if (!regList.isInstructor()) {
result.failAll("You must be an instructor to share an exercise");
return result;
}
// Get the exercise repository URL
ConfigurationSetting repoUrlSetting =
Database.getInstance().getConfigurationSetting(ConfigurationSettingName.PUB_REPOSITORY_URL);
if (repoUrlSetting == null) {
result.failAll("URL of exercise repository is not configured");
return result;
}
String repoUrl = repoUrlSetting.getValue();
if (repoUrl.endsWith("/")) {
repoUrl = repoUrl.substring(0, repoUrl.length() - 1);
}
HttpPost post = new HttpPost(repoUrl + "/exercisedata");
// Encode an Authorization header using the provided repository username and password.
String authHeaderValue =
"Basic "
+ DatatypeConverter.printBase64Binary(
(repoUsername + ":" + repoPassword).getBytes(Charset.forName("UTF-8")));
// System.out.println("Authorization: " + authHeaderValue);
post.addHeader("Authorization", authHeaderValue);
// Now go through and upload each problem
// For now, we do this one at a time
// In the future we could send problems and test cases
// to the repo in bulk, and add a new web service to handle it
for (Problem p : problems) {
// Look up the test cases
List<TestCase> testCaseList = Database.getInstance().getTestCasesForProblem(p.getProblemId());
ProblemAndTestCaseList exercise = new ProblemAndTestCaseList();
exercise.setProblem(p);
exercise.setTestCaseList(testCaseList);
// Convert the exercise to a JSON string
StringEntity entity;
StringWriter sw = new StringWriter();
try {
JSONConversion.writeProblemAndTestCaseData(exercise, sw);
entity = new StringEntity(sw.toString(), ContentType.create("application/json", "UTF-8"));
} catch (IOException e) {
// fail remaining test cases and return our results thus far
// some exercises may have been successfully shared
result.failRemaining("Could not convert exercise to JSON: " + e.getMessage());
return result;
}
post.setEntity(entity);
// POST the exercise to the repository
HttpClient client = new DefaultHttpClient();
try {
HttpResponse response = client.execute(post);
StatusLine statusLine = response.getStatusLine();
if (statusLine.getStatusCode() == HttpStatus.SC_OK) {
// Update the exercise's shared flag so we have a record that it was shared.
exercise.getProblem().setShared(true);
exercise.getProblem().setProblemAuthorship(ProblemAuthorship.IMPORTED);
Database.getInstance().storeProblemAndTestCaseList(exercise, course, authenticatedUser);
result.success();
} else if (statusLine.getStatusCode() == HttpStatus.SC_UNAUTHORIZED) {
result.failRemaining(
"Authentication with repository failed - incorrect username/password?");
return result;
} else {
result.failRemaining(
"Failed to publish exercise to repository: " + statusLine.getReasonPhrase());
return result;
}
} catch (ClientProtocolException e) {
result.failRemaining("Error sending exercise to repository: " + e.getMessage());
return result;
} catch (IOException e) {
result.failRemaining("Error sending exercise to repository: " + e.getMessage());
return result;
} finally {
client.getConnectionManager().shutdown();
}
}
result.allSucceeded(
"Successfully uploaded " + problems.length + " exercise to repository. Thanks!");
return result;
}