testmanagerbean.java

老外的在线考试

	/**
	 * Gets the test score data for a user. Optionally consider the test's suppressTestEndFeedback
	 * setting to hide the score when appropriate. If the score is hidden, this method returns null.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testId Test ID
	 * @param userId User ID
	 * @param applySuppressResults true to consider the test's suppressTestEndFeedback setting, false to ignore it.
	 * @return ScoreData instance storing score information, null if the user has not taken the test yet or if it has been suppressed by the test's suppressTestEndFeedback setting.
	 * @throws SchoolException if the test is missing.
	 */
	public ScoreData getTestScoreForUser(Integer testId, Integer userId, boolean applySuppressResults ) throws SchoolException
	{
		LocalUserTestAssoc assoc = findTestUserAssoc(testId, userId);
		if (assoc==null)
		{
			return null;		
		}

		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);
		}

		if (applySuppressResults && test.isSuppressTestEndFeedback() )
		{
			return null;
		}

		int score = assoc.getScore();
		int maxScore = assoc.getMaxScore();
		boolean taken = assoc.isTestCompleted() || (maxScore>0);
		boolean passed =  (maxScore>0) ? ( ((score*100)/maxScore) >= test.getPassPercentage() ) : false;

		// maxScore greater than 0 or test completed means that this testee has already taken the test.
		
		return new ScoreData( assoc.getUserId(), assoc.getTestId(), test.getName(),
			score, maxScore, passed , assoc.isExceededTestTime() , 
			taken, assoc.isTestCompleted(), 
			assoc.getLastModifiedDateTime() );
	}
	
	/**
	 * Adds/associates a set of tests to a set of users.
	 * If a test is already associated with a user, this method continues on with other tests/users.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testIds Array of test IDs to add
	 * @param userIds Array of user IDs to add tests to
	 * @return Number of users that are associated with tests by this method call.
	 * @throws SchoolException if a test is missing or some other error.
	 */
	public int addTestsToUsers( Integer[] testIds, Integer[] userIds) throws SchoolException
	{
		int numAdded = 0;
		for (int u=0; u<userIds.length; u++)
		{
			for (int t=0; t<testIds.length; t++)
			{
				if (addTestToUser(testIds[t], userIds[u]))
				{
					numAdded++;
				}
			}
		}
		return numAdded;
	}
	
	/**
	 * Simultaneously removes/disassociates a set of tests from the user, then adds/associates another set of tests to the user.
	 * This method is more efficient than calling removeTestFromUser(...) and addTestToUser(...)
	 * repeatedly to add/remove a large set of tests.
	 * If a test is already associated with this user during the association process, this method continues on with other tests.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testIdsToRemove Array of test IDs to remove
	 * @param testIdsToAdd Array of test IDs to add
	 * @param userId User ID
	 * @throws SchoolException if the test is missing or some other error.
	 */
	public void synchronizeTestsWithUser( Integer[] testIdsToRemove, Integer[] testIdsToAdd, Integer userId) throws SchoolException
	{
		if (testIdsToRemove!=null)
		{
			for (int t=0; t<testIdsToRemove.length; t++)
			{
				removeTestFromUser(testIdsToRemove[t], userId);
			}
		}
		
		if (testIdsToAdd!=null)
		{
			for (int t=0; t<testIdsToAdd.length; t++)
			{
				addTestToUser(testIdsToAdd[t], userId);
			}
		}
	}
	
	/**
	 * Associates a test to a user. If this association already exists, this method does nothing.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testId Test ID
	 * @param userId User ID
	 * @return true if this method call adds the test to with the user, false if they are already associated beforehand.
	 * @throws SchoolException if the test is missing.
	 */
	public boolean addTestToUser( Integer testId, Integer userId) throws SchoolException
	{
		boolean added = false;
		if (findTestUserAssoc(testId,userId)==null)
		{
			try
			{
				s_testHome.findByPrimaryKey(testId);
			}
			catch (FinderException fex)
			{
				throw new SchoolException(SchoolException.TEST_NOT_FOUND, "Cannot find Test with ID "+testId, fex);
			}
	
			s_logger.fine("Adding test "+testId+" to user "+userId);
			try
			{
				s_userTestAssocHome.create(testId, userId);	
				added = true;
			}
			catch (CreateException ex)
			{
				throw new SchoolException( "Failed to create LocalUserTestAssoc with Test ID="+testId+", User ID="+userId,ex);
			}
		}
		return added;
	}

	/**
	 * Disassociates a test from a user if such an association exists.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testId Test ID
	 * @param userId User ID
	 * @throws SchoolException if the test is missing or some other error.
	 */
	public void removeTestFromUser( Integer testId, Integer userId) throws SchoolException
	{
		
		try
		{
			s_testHome.findByPrimaryKey(testId);
		}
		catch (FinderException fex)
		{
			throw new SchoolException(SchoolException.TEST_NOT_FOUND, "Cannot find Test with ID "+testId, fex);
		}

		s_logger.fine("Removing test "+testId+" from user "+userId);
		UserTestAssocKey key = new UserTestAssocKey();
		key.setTestId(testId);
		key.setUserId(userId);
		LocalUserTestAssoc assoc = null;
		try
		{
			assoc = s_userTestAssocHome.findByPrimaryKey( key );
		}
		catch (FinderException fex)
		{
			assoc = null;
		}

		if (assoc!=null)
		{
			try
			{
				assoc.remove();
			}
			catch (Exception ex)
			{
				throw new SchoolException("Failed to remove LocalUserTestAssoc for Test ID="+testId+", User ID="+userId, ex);
			}
		}
	}
	
	/**
	 * Gets a user's historical records for a test and user.
	 *
	 * @ejb.interface-method
	 * @ejb.transaction type="Required"
	 *
	 * @param testId Test ID
	 * @param userId User ID
	 * @return List of AnswerHistoryData instances.
	 */
	public List getAnswerHistory(Integer testId, Integer userId) throws SchoolException
	{
		s_logger.fine("Getting answer history for test "+testId+", user "+userId);
		LinkedList historyList = new LinkedList();
		try
		{
			Collection historyCol = s_answerHistoryRecordHome.findByUserAndTest(userId,testId);
			Iterator hIter=historyCol.iterator();
			while (hIter.hasNext())
			{
				LocalAnswerHistoryRecord record = (LocalAnswerHistoryRecord)hIter.next();
				historyList.add( new AnswerHistoryData (
					record.getTestId(), record.getQuestionId(), record.getUserId(),
					record.getQuestionType(),
					record.getQuestionIndex(), record.getQuestionScore(),
					record.getUserAnswer(), record.getCorrectAnswer(),
					record.isAnswerCorrect(), record.getUserScore(),
					record.getTimestamp()) 
				);
			}
		}
		catch (Exception ex)
		{
			throw new SchoolException("Error getting answer history for test "+testId+", user "+userId, ex);
		}

		return historyList;
	}

    /**
     * Dummy create method.
     *
     * @ejb.create-method view-type="remote"
     */
    public void ejbCreate()
    {
        // Nothing here
    }


	private boolean canDeactivateTest(LocalTest test)
	{
		if (!test.isActive())
		{
			return false;
		}
		
		boolean hasAssoc = false;
		try
		{
			hasAssoc = !(s_userTestAssocHome.findByTest(test.getId()).isEmpty());
		}
		catch (FinderException fex)
		{
			// Ignore exception;
		}
		
		return !hasAssoc;
	}
	

	private LocalUserTestAssoc findTestUserAssoc(Integer testId, Integer userId)
	{
		LocalUserTestAssoc assoc = null;
		try
		{
			Iterator assocIter = s_userTestAssocHome.findByUserAndTest(userId, testId).iterator();
			if (assocIter.hasNext())
			{
				assoc = (LocalUserTestAssoc)assocIter.next();
			}
		}
		catch (Exception ex)
		{
			s_logger.log( Level.FINER, "LocalUserTestAssoc does not exist yet for Test ID="+testId+", User ID="+userId);
			assoc = null;
		}
		return assoc;
	}
	
	private TestData getDataFromTest(LocalTest test) throws FinderException
	{
		TestData data = new TestData(test.getId(), test.getName(), test.getOwner(),
			test.getOwnerHierarchyId(), test.getPassPercentage(), 
			test.getTimeLimitSeconds(), test.isMultiQuestionsMode(),
			test.isSuppressQuestionFeedback(), test.isSuppressTestEndFeedback(),
			canDeactivateTest(test));
		List relatedQuesList = new ArrayList(s_quesHome.findByTest(test.getId()));
		List unrelatedQuesList = new ArrayList(s_quesHome.findUnassignedToTest(true));

		ResourceListData[] relatedQuesDataArr = new ResourceListData[ relatedQuesList.size() ];
		for (int ridx=0; ridx<relatedQuesDataArr.length; ridx++)
		{
			LocalQuestion ques = (LocalQuestion)relatedQuesList.get(ridx);
			relatedQuesDataArr[ridx] = new ResourceListData(ques.getId(), ques.getName());
			relatedQuesDataArr[ridx].getProperties().put("description", StringUtils.truncate(ques.getContent(),30) );
			relatedQuesDataArr[ridx].getProperties().put("score", new Integer(ques.getScore()) );
		}

		ResourceListData[] unrelatedQuesDataArr = new ResourceListData[ unrelatedQuesList.size() ];
		for (int uidx=0; uidx<unrelatedQuesDataArr.length; uidx++)
		{
			LocalQuestion ques = (LocalQuestion)unrelatedQuesList.get(uidx);
			unrelatedQuesDataArr[uidx] = new ResourceListData(ques.getId(), ques.getName());
			unrelatedQuesDataArr[uidx].getProperties().put("description", StringUtils.truncate(ques.getContent(),30) );
			unrelatedQuesDataArr[uidx].getProperties().put("score", new Integer(ques.getScore()) );
		}

		data.setRelatedResources( relatedQuesDataArr );
		data.setUnrelatedResources( unrelatedQuesDataArr );
		return data;
	}

	private static LocalTestHome s_testHome = null;
	private static LocalQuestionHome s_quesHome = null;
	private static LocalUserTestAssocHome s_userTestAssocHome = null;
	private static LocalAnswerHistoryRecordHome s_answerHistoryRecordHome = null;
	static
	{
		try
		{
			Context ctx = new InitialContext();
			try
			{
				s_quesHome = (LocalQuestionHome)ctx.lookup(JNDI_PREFIX+LocalQuestionHome.JNDI_NAME);
				s_testHome = (LocalTestHome)ctx.lookup(JNDI_PREFIX+LocalTestHome.JNDI_NAME);
				s_userTestAssocHome = (LocalUserTestAssocHome)ctx.lookup(JNDI_PREFIX+LocalUserTestAssocHome.JNDI_NAME);
				s_answerHistoryRecordHome = (LocalAnswerHistoryRecordHome)ctx.lookup(JNDI_PREFIX+LocalAnswerHistoryRecordHome.JNDI_NAME);
			}
			finally
			{
				ctx.close();
			}
		}
		catch (NamingException nex)
		{
			throw new EJBException("Error retrieving homes", nex);
		}
	}

	private static Logger s_logger = Logger.getLogger( TestManagerBean.class.getName());
	
}