testmanagerbean.java

老外的在线考试

		{
			test.removeQuestion(ques);
			test.setLastModifiedMillis(System.currentTimeMillis());
		}
		catch (Exception ex)
		{
			getSessionContext().setRollbackOnly();
			throw new SchoolException("Error removing Question with ID "+quesId+" from Test with ID "+testId, ex);
		}
	}
	
	/**
	 * Gets list of summary data for questions belonging to a test.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testId Test ID.
	 * @param count Maximum number of resources to retrieve.
	 * @return Array of ResourceListData instances.
	 * @throws SchoolException if test is missing.
	 */
	public ResourceListData[] getQuestionsSummaryDataForTest( Integer testId, int count) throws SchoolException
	{
		LocalTest test =  null;
		try
		{
			test = s_testHome.findByPrimaryKey(testId);
		}
		catch (FinderException fex)
		{
			throw new SchoolException(SchoolException.TEST_NOT_FOUND, "Cannot find Test with ID "+testId, fex);
		}

		ResourceListData[] resources = null;
		try
		{
			List resourceList = test.getQuestions(count);
			resources = new ResourceListData[ resourceList.size() ];
			Iterator resourceIter = resourceList.iterator();
			for (int ridx=0; resourceIter.hasNext() && (ridx<resources.length); ridx++)
			{
				LocalQuestion ques = (LocalQuestion)resourceIter.next();
				
				resources[ridx] = new ResourceListData( ques.getId(), ques.getName());
				resources[ridx].getProperties().put("description", StringUtils.truncate(ques.getContent(),30) );
				resources[ridx].getProperties().put("score", new Integer(ques.getScore()) );
			}
		}
		catch (Exception ex)
		{
			throw new SchoolException("Error getting data for Questions in Test with ID "+testId, ex);
		}
		return resources;
	}
				
	/**
	 * Gets data of a test.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param id Test ID.
	 * @return TestData instance storing the test's data.
	 * @throws SchoolException if test is missing.
	 */
	public TestData getTestData(Integer id) throws SchoolException
	{
		LocalTest test =  null;
		try
		{
			test = s_testHome.findByPrimaryKey(id);
		}
		catch (FinderException fex)
		{
			throw new SchoolException(SchoolException.TEST_NOT_FOUND, "Cannot find Test with ID "+id, fex);
		}

		TestData data = null;
		try
		{
			data = getDataFromTest(test);
		}
		catch (Exception ex)
		{
			throw new SchoolException("Error getting data for Test with ID "+id, ex);
		}
		return data;
	}

	/**
	 * Updates the data of an existing test.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param id Test ID.
	 * @param data TestData instance with the test's data.
	 * @throws EJBException if test is missing
	 * @throws SchoolException if there is a problem updating the test.
	 */
	public void setTestData(Integer id, TestData data) throws SchoolException
	{
		LocalTest test =  null;
		try
		{
			test = s_testHome.findByPrimaryKey(id);
		}
		catch (FinderException fex)
		{
			throw new SchoolException(SchoolException.TEST_NOT_FOUND, "Cannot find Test with ID "+id, fex);
		}

		try
		{
			test.setName( data.getName() );
			test.setOwnerHierarchyId( data.getOwnerHierId() );
			test.setPassPercentage(data.getPassPercentage());
			test.setMultiQuestionsMode( data.isMultiQuestionsMode());
			test.setSuppressQuestionFeedback(data.isSuppressQuestionFeedback());
			test.setSuppressTestEndFeedback(data.isSuppressTestEndFeedback());
			test.setTimeLimitSeconds( data.getTimeLimitSeconds());
			test.setLastModifiedMillis(System.currentTimeMillis());
			
			Integer[] resIdsToRemove = data.getResourceIdsToRemove();
			for (int r=0; r<resIdsToRemove.length; r++)
			{
				removeQuestionFromTest(id, resIdsToRemove[r]);
			}
			
			Integer[] resIdsToAdd = data.getResourceIdsToAdd();
			for (int r=0; r<resIdsToAdd.length; r++)
			{
				addQuestionToTest(id, resIdsToAdd[r]);
			}
		}
		catch (Exception ex)
		{
			getSessionContext().setRollbackOnly();
			throw new SchoolException("Error setting data for Test with ID "+id, ex);
		}
	}

	/**
	 * Checks the user's answers for a contiguous block of questions. 
	 * The user is awarded a score for each correctly answered question.
	 * These scores are added together and returned in an AnswerStatus instance. 
	 * This method also creates an AnswerHistoryRecordBean instance 
	 * for each of the answers to log this answer and the awarded score. 
	 * This method is intended to be used by a client that 
	 * evaluates multiple questions at a time.
	 * 
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testId Test ID
	 * @param quesIds Array of Question IDs
	 * @param userId User ID
	 * @param offset Offset of the first question in quesIds relative to the first question within the test.
	 * @param userAnswers Array of user's answer, format depends on question type, array length must equal that of quesIds.
	 * @param testSecs Amount of time in seconds the user took to complete the test (applicable only if testSecs is larger than 0, endOfTest is true and multiQuestionsMode is enabled).
	 * @param endOfTest true if this is the last block of questions in the test, false if there are following blocks.
	 * @return The resultant status of the answers.
	 * @throws SchoolException if the test or a question is missing, or some other error.
	 */
	public AnswerStatus checkMultiQuestionAnswers(Integer testId, Integer[] quesIds, Integer userId,
		int offset, String[] userAnswers, int testSecs, boolean endOfTest) throws SchoolException
	{
		if (quesIds.length != userAnswers.length)
		{
			throw new SchoolException(SchoolException.UNSPECIFIED, "Number of answers ("+userAnswers.length+") does not match number fo questions ("+quesIds.length+")");
		}
		
		int status = AnswerStatus.WRONG;
		int scoreToAdd = 0;
		for (int q=0; q<quesIds.length; q++)
		{
			final boolean lastQuesInTest = endOfTest && (q==quesIds.length-1);
			AnswerStatus quesStatus = checkQuestionAnswer(testId, quesIds[q], userId,
					offset+q, userAnswers[q], testSecs, 0, lastQuesInTest );
			scoreToAdd += quesStatus.getScore();			
			if (status == AnswerStatus.CORRECT)
			{	// Correct status can be overriden by all other statuses
				status = quesStatus.getStatus();
			}
			else if (status == AnswerStatus.WRONG)
			{	// Wrong status can be overriden by only test timed out status
				if (quesStatus.getStatus() == AnswerStatus.TEST_TIMED_OUT)
				{
					status = AnswerStatus.TEST_TIMED_OUT;
				}
			}
			// Timed out status cannot be overridden.
		}
		
		return new AnswerStatus(status, scoreToAdd);
	}
	
	/**
	 * Checks the user's answer for a question. The user is
	 * awarded a score if the answer is correct. This method also
	 * creates an AnswerHistoryRecordBean instance to log this answer
	 * and the awarded score. 
	 * This method is intended to be used by a client that 
	 * evaluates one question at a time.
	 * 
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testId Test ID
	 * @param quesId Question ID
	 * @param userId User ID
	 * @param quesIndex Index of the question within the test.
	 * @param userAnswer User's answer, format depends on question type.
	 * @param testSecs Amount of time in seconds the user took to complete the test (applicable only if testSecs is larger than 0, endOfTest is true and multiQuestionsMode is enabled).
	 * @param quesSecs Amount of time in seconds the user took to answer this question (applicable only if quesSecs is larger than 0 and multiQuestionsMode is disabled).
	 * @param endOfTest true if this is the last question in the test, false if there are following questions.
	 * @return The resultant status of the answer.
	 * @throws SchoolException if the test or question is missing, or some other error.
	 */
	public AnswerStatus checkQuestionAnswer(Integer testId, Integer quesId, Integer userId,
		int quesIndex, String userAnswer, int testSecs, int quesSecs, boolean endOfTest) throws SchoolException
	{
        LocalTest test =  null;
        try
        {
            test = s_testHome.findByPrimaryKey(testId);
        }
        catch (FinderException fex)
        {
            throw new SchoolException(SchoolException.TEST_NOT_FOUND, "Cannot find Test with ID "+testId, fex);
        }

        LocalQuestion ques =  null;
		try
		{
			ques = s_quesHome.findByPrimaryKey(quesId);
		}
		catch (FinderException fex)
		{
			throw new SchoolException(SchoolException.QUESTION_NOT_FOUND, "Cannot find Question with ID "+quesId, fex);
		}


		int status = AnswerStatus.WRONG;
		boolean exceedTestTime = false;
		boolean exceedQuesTime = false;
		int quesScore = 0;
		String quesAnswer = null;
		Integer quesType = ques.getType();
		int scoreToAdd = 0;
		boolean answerCorrect = false;
		try
		{
			double result = ques.checkResponse(userAnswer);
			// Use 0.5 as a threshold for determining whether the answer is correct or not.
			// For some question type, correctness has no real meaning, but its no harm setting it anyway since it'll just be ignore by the client.
			answerCorrect = (result>0.5);
			status = answerCorrect ? AnswerStatus.CORRECT : AnswerStatus.WRONG;

			quesScore = ques.getScore();
			quesAnswer = ques.getAnswer();
			quesType = ques.getType();

			// Score to add depends on the question type			
			if (IQuestionType.SINGLE_CHOICE_TYPE.equals(quesType) || IQuestionType.MULTIPLE_CHOICE_TYPE.equals(quesType))
			{
				scoreToAdd = (status == AnswerStatus.CORRECT) ? quesScore : 0;
			}
			else if (IQuestionType.KEYWORDS_TYPE.equals(quesType))
			{
				if (ques.isMustMatchAllKeywords())
				{
					scoreToAdd = (status == AnswerStatus.CORRECT) ? quesScore : 0;
				}
				else
				{
					scoreToAdd = (int)(result * quesScore);
				}
			}
						
			if (test.isMultiQuestionsMode())
			{
				if (endOfTest && (testSecs>0) && (test.getTimeLimitSeconds()>0))
				{
					exceedTestTime = (testSecs > test.getTimeLimitSeconds());
					status = exceedTestTime ? AnswerStatus.TEST_TIMED_OUT : status;
					scoreToAdd = 0;
				}
			}
			else
			{
				if ((quesSecs>0) && (ques.getTimeLimitSeconds()>0))
				{
					exceedQuesTime = (quesSecs > ques.getTimeLimitSeconds());
					status = exceedQuesTime ? AnswerStatus.QUESTION_TIMED_OUT : status;
					scoreToAdd = 0;
				}
			}
		}
		catch (Exception ex)
		{
			throw new SchoolException("Error checking answer for Question with ID "+quesId, ex);
		}

		
		try
		{
			s_logger.fine("Adding score "+scoreToAdd+" for test "+testId+", question "+quesId+" to user "+userId);
			LocalUserTestAssoc assoc = findTestUserAssoc(testId, userId);
			if (assoc==null)
			{
				assoc = s_userTestAssocHome.create(testId, userId);
			}
			assoc.addScore(scoreToAdd, quesScore);
			if (endOfTest)
			{
				assoc.setTestCompleted(true);
			}
			
			if (exceedTestTime)
			{
				assoc.exceededTestTime();
			}
		}
		catch (CreateException cex)
		{
			getSessionContext().setRollbackOnly();
			throw new SchoolException("Error creating Score for Test ID="+testId+", User ID="+userId, cex);
		}
		catch (Exception ex)
		{
			getSessionContext().setRollbackOnly();
			throw new SchoolException("Error adding score for Test ID="+testId+", User ID="+userId, ex);
		}

		try
		{
			s_answerHistoryRecordHome.create(testId, quesId, userId, quesType, quesIndex, quesScore, scoreToAdd, userAnswer, quesAnswer, answerCorrect, exceedQuesTime);			
		}
		catch (CreateException cex)
		{
			getSessionContext().setRollbackOnly();
			throw new SchoolException("Error creating history record for Test ID="+testId+", Question ID="+quesId+", User ID="+userId, cex);
		}
		catch (Exception ex)
		{
			getSessionContext().setRollbackOnly();
			throw new SchoolException("Error creating history record for Test ID="+testId+", Question ID="+quesId+", User ID="+userId, ex);
		}
		return new AnswerStatus(status, scoreToAdd);
	}