startexamaction.java

JAVA编写的远程教育程序,包含了教育学的基本思想和网络应用程序的基本开发模式

package com.whatratimes.webedu.student;

import com.whatratimes.dbms.DBHelper;
import com.whatratimes.dbms.InsertSQLExecuter;
import com.whatratimes.dbms.QuerySQLExecuter;
import com.whatratimes.util.PaperHelper;
import com.whatratimes.tables.t_exam;
import com.whatratimes.tables.t_user;
import org.apache.struts.action.Action;
import org.apache.struts.action.ActionForm;
import org.apache.struts.action.ActionForward;
import org.apache.struts.action.ActionMapping;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpSession;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Hashtable;

/**
 * User: Tao
 * Date: Jun 15, 2003
 * Time: 8:26:07 AM
 */
public class StartExamAction extends Action
{
    public static final SimpleDateFormat SDF = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    public ActionForward execute(ActionMapping actionMapping, ActionForm actionForm, HttpServletRequest httpServletRequest, HttpServletResponse httpServletResponse) throws Exception
    {
        String assign = httpServletRequest.getParameter("AssignmentId");

        String submit = httpServletRequest.getParameter("SubmitId");

        HttpSession session = httpServletRequest.getSession();

        Hashtable this_assign = (Hashtable) session.getAttribute("CurrentAssignment");

        if (assign == null || this_assign == null)
        {
            return actionMapping.findForward("failed");
        }

        t_user user = (t_user) session.getAttribute("User");

        int duration = ((Integer) this_assign.get("Duration")).intValue();

        Integer answered = new Integer(0);

        Integer submit_id;


        int qt = ((Integer) this_assign.get("QuestionType")).intValue();

//        Hashtable old_instance;

        if (submit == null)
        {

            // start new exam.

            Integer paper_id = null;

            if (qt == 1)
            {
                // Choices paper will generated.

                QuerySQLExecuter tt = new QuerySQLExecuter();

                tt.setReturnClassName("t_exam");

                tt.appendColumn("b.ExamId", "ExamId");
                tt.appendColumn("b.CourseId", "CourseId");
                tt.appendColumn("b.ExamType", "ExamType");
                tt.appendColumn("b.QuestionType", "QuestionType");
                tt.appendColumn("b.NumberOfQuestion", "NumberOfQuestion");

                // 增加单元、章、节的信息
                tt.appendColumn("b.Unit", "Unit");
                tt.appendColumn("b.Chapter", "Chapter");
                tt.appendColumn("b.Section", "Section");

                tt.appendTableName("t_exam_assigned", "a");
                tt.appendTableName("t_exam", "b");

                tt.appendWhereCondition("a.AssignmentId", "=", Integer.valueOf(assign));
                tt.appendWhereClause("a.ExamId = b.ExamId");

                Object[] tr = tt.executeQuery();

                if (tr.length > 0)
                {
                    paper_id = PaperHelper.generatePaperBeforeExam((t_exam) tr[0]);

                    if (paper_id == null)
                    {
                        session.setAttribute("ErrorMsg", "由于题库中没有足够的符合条件的试题，不能生成选择题试卷。");
                        return actionMapping.findForward("failed");
                    }
                }

            } else if ( qt == 2 )
            {
                paper_id = PaperHelper.selectPaper(Integer.valueOf(assign), new Integer(user.UserId));
                if (paper_id == null)
                {
                    session.setAttribute("ErrorMsg", "您已经做完了本考试的全部试卷。");
                    return actionMapping.findForward("failed");
                }

            } else if ( qt == 3 )
            {

                paper_id = PaperHelper.selectPracticePaper(Integer.valueOf(assign), new Integer(user.UserId));
                if (paper_id == null)
                {
                    session.setAttribute("ErrorMsg", "没有可用试卷。");
                    return actionMapping.findForward("failed");
                }
            }

            Date d = new Date();
            session.setAttribute("StartTime", SDF.format(d));
            session.setAttribute("EndTime", SDF.format(new Date(d.getTime() + 60 * 1000 * duration)));

            submit_id = new Integer(DBHelper.getNextSubmitId());

            InsertSQLExecuter isql = new InsertSQLExecuter();
            isql.appendTableName("t_exam_submit");
            isql.appendValue("SubmitId", submit_id);
            isql.appendValue("PaperId", paper_id);
            isql.appendValue("UserId", new Integer(user.UserId));
            isql.appendValue("AssignmentId", Integer.valueOf(assign));
            isql.appendValue("InstanceId", this_assign.get("NextInstanceId"));
            isql.appendValue("StartTime", d);
            isql.appendValue("Mark", new Integer(0));
            isql.appendValue("State", new Integer(1));

            isql.executeUpdate();
        } else
        {
            // continue exam
            submit_id = Integer.valueOf(submit);
            Date d = StudyHelper.getUnsubmittedInstance(submit_id);
            answered = StudyHelper.getAnsweredNumber(submit_id);

            session.setAttribute("StartTime", SDF.format(d));
            session.setAttribute("EndTime", SDF.format(new Date(d.getTime() + 60 * 1000 * duration)));

        }

        session.setAttribute("Answered", answered);
        session.setAttribute("SubmitId", submit_id);

        StudyHelper.setQuestions(submit_id, qt, session);


        if (qt == 1)
        {
            return actionMapping.findForward("choice");
        } else if (qt == 2)
        {
            return actionMapping.findForward("answer");
        } else if (qt == 3)
        {
            return actionMapping.findForward("practice");
        }

        return actionMapping.findForward("failed");
    }
}