editquestionaction.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.test;

import javax.servlet.*;
import javax.servlet.http.*;
import org.apache.struts.action.*;
import com.cyberdemia.school.*;
import com.cyberdemia.cybertester.*;
import java.util.logging.*;
import com.cyberdemia.cybertester.admin.*;

/**
 * 
 * EditQuestionAction is a Struts action to load the question editor page.
 *  
 * @author Alexander Yap
 */
public final class EditQuestionAction extends AbstractAdminAction
{
	protected ActionForward doPerform(
		ActionMapping mapping, ActionForm form,
		HttpServletRequest request, HttpServletResponse response,
		HttpSession session) throws Exception
	{
		Logger logger = CyberTesterUtils.getLogger();
		String mode = request.getParameter(AdminConstants.MODE_KEY);
		if (mode==null)
		{
			mode = AdminConstants.EDITOR_NEW_MODE;
		}
		session.setAttribute(AdminConstants.MODE_KEY, mode);
		if (form==null)
		{
			form = new QuestionForm();
			if ("request".equals(mapping.getScope()))
				request.setAttribute(mapping.getAttribute(), form);
			else
				session.setAttribute(mapping.getAttribute(), form);
		}
		QuestionForm quesForm = (QuestionForm)form;
		String testId = CyberTesterUtils.getParameterOrRequestAttribute(request,AdminConstants.TEST_ID_KEY);
		request.setAttribute(AdminConstants.TEST_ID_KEY, testId);
		
		// populate the form with data if editing existing question.
		if (AdminConstants.EDITOR_EDIT_MODE.equalsIgnoreCase(mode))
		{
			String quesId = request.getParameter(AdminConstants.QUESTION_ID_KEY);
			if (quesId!=null)
			{			
				try
				{
					QuestionManagerHome qMgrHome = CyberTesterUtils.getQuestionManagerHome();
					QuestionManager quesMgr = (QuestionManager)qMgrHome.create();
					QuestionData ques = quesMgr.getQuestionData(quesId);
					quesForm.setQuesId(quesId);
					quesForm.setTitle( ques.getName() );
					quesForm.setQuestionText( ques.getQuestion() );
					quesForm.setHintText( ques.getHint() );
					quesForm.setExplanationText( ques.getExplanation());
					quesForm.setDifficultyStr( ques.getDifficulty().getStr() );
                    quesForm.setTimeLimitSeconds(ques.getTimeLimitSeconds());
					quesForm.setAnswer( ques.getAnswer().intValue() );
					String[] choices = ques.getAnswerChoices();
					if (choices.length>=1)
						quesForm.setAnswerChoice0( choices[0] );
					if (choices.length>=2)
						quesForm.setAnswerChoice1( choices[1] );
					if (choices.length>=3)
						quesForm.setAnswerChoice2( choices[2] );
					if (choices.length>=4)
						quesForm.setAnswerChoice3( choices[3] );
				}
				catch (Exception ex)
				{
					logger.log( Level.SEVERE, "Error transferring Question data to form.", ex);
					throw ex;
				}
			}
			else
			{
				quesForm.reset(mapping,request);
				throw new ServletException("Missing parameter "+AdminConstants.QUESTION_ID_KEY);
			}
		}
		else
		{
			String hierId = (String)session.getAttribute(AdminConstants.SELECTED_HIERARCHY_ID_KEY);
			if (hierId==null)
			{
				ActionErrors errors = new ActionErrors();
				errors.add(ActionErrors.GLOBAL_ERROR, new ActionError("error.hierarchyNode.unselected"));
				saveErrors(request, errors);
				return mapping.findForward(Constants.ERROR);
			}
			quesForm.reset(mapping,request);
		}

		// Set a transactional control token to prevent double posting		 
		saveToken(request);
		return (mapping.findForward(Constants.SUCCESS));
	}
}