getuserpercentagesdistributionaction.java

老外的在线考试

/*
 * CyberTester - J2EE Web application for creating, delivering and managing tests/exams/surveys. 
 * Copyright (C) 2003 CyberDemia Research and Services Pty Ltd
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program (see the file COPYING); 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 program for complete text of license.
 */
package com.cyberdemia.cybertester.admin.report;

import java.util.*;
import java.io.ByteArrayOutputStream;
import java.awt.Font;
import javax.servlet.http.*;
import org.apache.struts.action.*;
import com.cyberdemia.school.*;
import com.cyberdemia.cybertester.*;
import com.cyberdemia.cybertester.common.*;
import java.util.logging.*;
import com.cyberdemia.cybertester.admin.*;
import org.jfree.chart.*;
import org.jfree.data.*;
import org.jfree.chart.labels.*;
import org.jfree.chart.axis.*;
import org.jfree.chart.renderer.*;
import org.jfree.chart.entity.StandardEntityCollection;
import org.jfree.chart.plot.PlotOrientation;

/**
 * 
 * GetUserPercentagesDistributionAction is a Struts action to retrieve distribution
 * of users' percentages.
 *
 * @author Alexander Yap
 */
public final class GetUserPercentagesDistributionAction extends AbstractAdminAction
{
	protected ActionForward doPerform(
		ActionMapping mapping, ActionForm form,
		HttpServletRequest request, HttpServletResponse response,
		HttpSession session) throws Exception
	{
		Logger logger = CyberTesterUtils.getLogger();
		try
		{

			DefaultCategoryDataset dataset = new DefaultCategoryDataset();
			// Calculation various distributions by questions
			ReportGeneratorHome reportGenHome = CyberTesterUtils.getReportGeneratorHome();
			ReportGenerator reportGen = (ReportGenerator)reportGenHome.create();
			Map distMap = reportGen.getScorePercentageDistributionByUsers(10.0);
			Iterator highValIter = distMap.keySet().iterator();
			int maxCount = 100;
			while (highValIter.hasNext())
			{
				Double highVal = (Double)highValIter.next();
				Integer count = (Integer)distMap.get(highVal);
				if (count.intValue() > maxCount)
				{
					maxCount = count.intValue();
				}
				dataset.addValue(count, "0", highVal);
			}

			JFreeChart chart = ChartFactory.createBarChart(
				"",
				"Overall score %", "Number of users", dataset, PlotOrientation.VERTICAL, false, true, false);
			chart.setTitle(new TextTitle("User % Distribution", new Font("SansSerif",Font.BOLD, 12)));
			((CategoryAxis)chart.getCategoryPlot().getDomainAxis()).setVerticalCategoryLabels(true);
			CategoryItemRenderer renderer = chart.getCategoryPlot().getRenderer();
			ValueAxis rangeAxis = chart.getCategoryPlot().getRangeAxis();
			rangeAxis.setMaximumAxisValue((double)maxCount);
			rangeAxis.setMinimumAxisValue(0.0);
			renderer.setItemLabelGenerator(
				new CategoryItemLabelGenerator()
				{
					public String generateItemLabel(CategoryDataset data, int series, int category)
					{
						return data.getValue(series, category).toString();
					}

					public String generateToolTip(CategoryDataset data, int series, int category)
					{
						String lowerVal = (category>0) ? data.getColumnKey(category-1).toString() : "0";
						return "Number of users scoring "+lowerVal+"%-"+data.getColumnKey(category)+"% : "+data.getValue(series, category).toString();
					}
				}
			);

			chart.setAntiAlias(true);
			int width = 600;
			int height = 600;
			try
			{
				width = Integer.parseInt( request.getParameter("width") );
			}
			catch (NumberFormatException nfex)
			{ }
			try
			{
				height = Integer.parseInt( request.getParameter("height") );
			}
			catch (NumberFormatException nfex)
			{ }
			
			final ByteArrayOutputStream baos = new ByteArrayOutputStream();
			final ChartRenderingInfo info = new ChartRenderingInfo(new StandardEntityCollection());
			ChartUtilities.writeChartAsPNG( baos , chart,width, height, info );
			ChartDataCache cache = new ChartDataCache();
			cache.data = baos.toByteArray();
			cache.info = info;
			Map chartsCache = (Map)session.getAttribute(Constants.CHARTS_CACHE_KEY);
			String chartId = String.valueOf(System.currentTimeMillis());
			chartsCache.put(chartId, cache);
			request.setAttribute(Constants.CHART_ID_KEY, chartId );
		}
		catch (Exception ex)
		{
			logger.log( Level.SEVERE, "Error getting user percentages distribution", ex);
			throw ex;
		}
			
		return mapping.findForward(Constants.SUCCESS);
	}

}