reportgeneratorbean.java

老外的在线考试

/*
 * SchoolEJB - CyberDemia's library of EJBs for educational related services.
 * Copyright (C) 2003 CyberDemia Research and Services
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 *
 * See the COPYING file located in the top-level-directory of
 * the archive of this library for complete text of license.
 */
package com.cyberdemia.school.impl;
import javax.ejb.*;
import javax.naming.*;
import java.util.*;
import com.cyberdemia.school.*;
import java.util.logging.*;
import com.cyberdemia.value.*;

/**
* ReportGeneratorBean is a session bean facade for retrieving and processing data 
* for reports based on historical records.
*
* @author Alexander Yap
*/
public class ReportGeneratorBean implements SessionBean
{
	public ReportGeneratorBean()
	{
		try
		{
			Context ctx = new InitialContext();
			m_testHome = (LocalTestHome)ctx.lookup("java:comp/env/ejb/localTest");
			m_quesHome = (LocalQuestionHome)ctx.lookup("java:comp/env/ejb/localQuestion");
			m_answerHistoryRecordHome =  (LocalAnswerHistoryRecordHome)ctx.lookup("java:comp/env/ejb/localAnswerHistoryRecord");
		}
		catch (NamingException nex)
		{
			throw SchoolUtils.convertToEJBException(nex);
		}
	}
	
	
	/**
	 * Gets a user's historical records for a test and user.
	 * @param testId Test ID
	 * @param userId User ID
	 * @return List of AnswerHistoryData instances.
	 */
	public List getAnswerHistory(String testId, String userId)
	{
		s_logger.fine("Getting answer history for test "+testId+", user "+userId);
		LinkedList historyList = new LinkedList();
		try
		{
			Collection historyCol = m_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.getQuestionIndex(), record.getQuestionScore(),
					record.getUserAnswer(), record.getCorrectAnswer(),
					record.isAnswerCorrect(), record.getTimestamp()) 
				);
			}
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.SEVERE, "Error getting answer history for test "+testId+", user "+userId, fex);
			throw SchoolUtils.convertToEJBException(fex);
		}
		catch (RuntimeException ex)
		{
			s_logger.log( Level.SEVERE, "Error getting answer history for test "+testId+", user "+userId, ex);			
			throw ex;
		}

		return historyList;
	}

	/**
	 * Gets the distribution of users' answers for all the questions in a test.
	 * @param testId Test ID
	 * @return SortedMap containing the question indices (Integer objects) as the keys and count of correct answers (Integer objects) as the values.
	 */
	public SortedMap getAnswersDistributionForTest(String testId)
	{
		s_logger.fine("Getting answers distribution for test "+testId);
		Map tmpDistMap = new HashMap();
		try
		{
			Collection historyCol = m_answerHistoryRecordHome.findByTest(testId);
			Iterator hIter=historyCol.iterator();
			while (hIter.hasNext())
			{
				LocalAnswerHistoryRecord record = (LocalAnswerHistoryRecord)hIter.next();
				Integer quesIndex = new Integer(record.getQuestionIndex());
				IntegerType correctAnswerCounter = (IntegerType)tmpDistMap.get(quesIndex);
				if (correctAnswerCounter==null)
				{
					correctAnswerCounter = new IntegerType();
					tmpDistMap.put(quesIndex, correctAnswerCounter);
				}
				if (record.isAnswerCorrect())
				{
					correctAnswerCounter.add(1);
				}
			}
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.SEVERE, "Error getting answers distribution for test "+testId, fex);
			throw SchoolUtils.convertToEJBException(fex);
		}
		catch (RuntimeException ex)
		{
			s_logger.log( Level.SEVERE, "Error getting answers distribution for test "+testId, ex);			
			throw ex;
		}

		SortedMap distMap = new TreeMap();
		Iterator idxIter = tmpDistMap.keySet().iterator();
		while( idxIter.hasNext() )
		{
			Object idx = idxIter.next();
			distMap.put(idx, new Integer(((IntegerType)tmpDistMap.get(idx)).getValue()) );
		}
		return distMap;
	}

	/**
	 * Gets the distribution of score percentages for all the questions in a test.
	 * @param testId Test ID
	 * @param type Type of percentages to calculate, determines the value to divide by, must be one of ReportGenerator.PERCENTAGE_BY_TEST or ReportGenerator.PERCENTAGE_BY_QUESTION.
	 * @return SortedMap containing the question indices (Integer objects) as the keys and percentages (Double objects) as the values.
	 */
	public SortedMap getScorePercentageDistributionForTest(String testId, int type)
	{
		s_logger.fine("Getting score percentage distribution for test "+testId);
		Map quesScoreSumMap = new HashMap();
		Map maxQuesScoreMap = (type==ReportGenerator.PERCENTAGE_BY_QUESTION) ? new HashMap() : null;
		int maxTestScore = 0;
		try
		{
			Collection historyCol = m_answerHistoryRecordHome.findByTest(testId);
			Iterator hIter=historyCol.iterator();
			while (hIter.hasNext())
			{
				LocalAnswerHistoryRecord record = (LocalAnswerHistoryRecord)hIter.next();
				Integer quesIndex = new Integer(record.getQuestionIndex());
				IntegerType quesScoreSum = (IntegerType)quesScoreSumMap.get( quesIndex);
				if (quesScoreSum==null)
				{
					quesScoreSum = new IntegerType();
					quesScoreSumMap.put( quesIndex, quesScoreSum);
				}
				quesScoreSum.add( record.getUserScore() );
				
				if (type==ReportGenerator.PERCENTAGE_BY_TEST)
				{
					maxTestScore += record.getQuestionScore();
				}
				else if (type==ReportGenerator.PERCENTAGE_BY_QUESTION)
				{
					IntegerType maxQuesScore = (IntegerType)maxQuesScoreMap.get(quesIndex);
					if (maxQuesScore==null)
					{
						maxQuesScore = new IntegerType();
						maxQuesScoreMap.put( quesIndex, maxQuesScore );
					}
					maxQuesScore.add( record.getQuestionScore() );
				}
			}
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.SEVERE, "Error getting score percentage distribution for test "+testId, fex);
			throw SchoolUtils.convertToEJBException(fex);
		}
		catch (RuntimeException ex)
		{
			s_logger.log( Level.SEVERE, "Error getting score percentage distribution for test "+testId, ex);			
			throw ex;
		}
		
		SortedMap distMap = new TreeMap();
		Iterator quesIndexIter = quesScoreSumMap.keySet().iterator();
		while ( quesIndexIter.hasNext() )
		{
			Integer quesIndex = (Integer)quesIndexIter.next();
			IntegerType quesScoreSumObj = (IntegerType)quesScoreSumMap.get( quesIndex );
			int quesScoreSum = (quesScoreSumObj!=null) ? quesScoreSumObj.getValue() : 0;
			int divideBy = 0;
			if (type==ReportGenerator.PERCENTAGE_BY_TEST)
			{
				divideBy = maxTestScore;
			}
			else if (type==ReportGenerator.PERCENTAGE_BY_QUESTION)
			{
				IntegerType maxQuesScore = (IntegerType)maxQuesScoreMap.get(quesIndex);
				divideBy = (maxQuesScore!=null) ? maxQuesScore.getValue() : 0;
			}

			double percentage = (divideBy!=0) ? ((double)quesScoreSum*100.0/divideBy) : 0.0;
			distMap.put( quesIndex, new Double(percentage) );
		}
		
		return distMap;
	}

	/**
	 * Gets the distribution of overall score percentages for all users.
	 * A user's overall percentage is calculated by divided the user's total score by his maximum possible score.
	 * The percentages are grouped into categories with the specified range. For example, if categoryRange is
	 * 22.0, the percentages are grouped into 0%-22%, 22%-44%, 44%-66%, 66%-88% and 88%-100% (the highest 
	 * category's limit is truncated to 100%).
	 * @param categoryRange Range of a category.
	 * @return SortedMap containing the upper-values of percentage categories (Double objects) as the keys and counts of users within a range (Integer objects) as the values.
	 */
	public SortedMap getScorePercentageDistributionByUsers(double categoryRange)
	{
		// Make sure categoryRange is not -ve, too small or too large.
		if ((categoryRange<0.01) || (categoryRange>99.99))
		{
			throw new IllegalArgumentException("Invalid value "+categoryRange+" for categoryRange, must be between 0.01 and 99.99");
		}
	
		// Need to calculate total scores for all users.
		// userTotalScoreMap stores the total scores for all users.
		Map userTotalScoreMap = new HashMap();
		// userMaxScoreMap stores the maximum scores for all users.
		Map userMaxScoreMap = new HashMap();
		try
		{
			Collection historyCol = m_answerHistoryRecordHome.findAll();
			Iterator historyIter = historyCol.iterator();
			while (historyIter.hasNext())
			{
				LocalAnswerHistoryRecord record = (LocalAnswerHistoryRecord)historyIter.next();
				String userId = record.getUserId();
				IntegerType userTotalScore = (IntegerType)userTotalScoreMap.get(userId);
				if (userTotalScore==null)
				{
					userTotalScore = new IntegerType();
					userTotalScoreMap.put( userId, userTotalScore);
				}
				userTotalScore.add( record.getUserScore() );
				IntegerType userMaxScore = (IntegerType)userMaxScoreMap.get(userId);
				if (userMaxScore==null)
				{
					userMaxScore = new IntegerType();
					userMaxScoreMap.put( userId, userMaxScore);
				}
				userMaxScore.add( record.getQuestionScore() );
				
			}
		}
		catch (FinderException fex)
		{
			s_logger.log( Level.SEVERE, "Error getting score percentage distribution by users.", fex);
			throw SchoolUtils.convertToEJBException(fex);
		}
		catch (RuntimeException ex)
		{
			s_logger.log( Level.SEVERE, "Error getting score percentage distribution by users", ex);			
			throw ex;
		}
		
		List highValueList = new ArrayList();
		List distCountList = new ArrayList();
		boolean finished = false;
		double highVal=categoryRange;
		while ( !finished )
		{
			if (highVal>=100.00)
			{
				highVal = 100.00;
				finished = true;
			}
			highValueList.add( new Double(highVal) );
			distCountList.add( new IntegerType() );		
			highVal+=categoryRange;
		}

		// Go through the users, calculate their percentages, and increment the appropriate categories.
		Iterator userIdIter = userTotalScoreMap.keySet().iterator();
		int highValuesCount = highValueList.size();
		while (userIdIter.hasNext())
		{
			String userId = (String)userIdIter.next();
			IntegerType userTotalScore = (IntegerType)userTotalScoreMap.get(userId);
			assert userTotalScore!=null : "Missing userTotalScore";
			IntegerType userMaxScore = (IntegerType)userMaxScoreMap.get(userId);
			assert userMaxScore!=null : "Missing userMaxScore";
			
			double percentage = (userMaxScore.getValue()>0) ? (userTotalScore.getValue()*100/userMaxScore.getValue()) : 0.0 ;
		
			Double categoryHighVal = null;
			for (int highValIndex=0; highValIndex < highValuesCount; highValIndex++)
			{
				Double highValD = (Double)highValueList.get(highValIndex);
				if (highValD.doubleValue() >= percentage )
				{
					((IntegerType)distCountList.get(highValIndex)).add( 1 );
					break;
				}
			}
		}

		SortedMap distMap = new TreeMap();
		for (int highValIndex=0; highValIndex < highValuesCount; highValIndex++)
		{
			distMap.put( highValueList.get(highValIndex), new Integer(((IntegerType)distCountList.get(highValIndex)).getValue()) );
		}

		return distMap;
	}

	//-----------------------------
	// Container methods.
	//-----------------------------

	public void ejbCreate() {}
	public void ejbPostCreate() { }
	public void ejbRemove() {}
	public void ejbActivate() {}
	public void ejbPassivate() {}
	
	public void setSessionContext(SessionContext sc) 
	{
		m_context = sc;
	}

	private SessionContext m_context = null;
	private LocalTestHome m_testHome = null;
	private LocalQuestionHome m_quesHome = null;
	private LocalAnswerHistoryRecordHome m_answerHistoryRecordHome = null;

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