Schedule.java

import java.util.*;
import java.sql.*;

public class Schedule {
    String name;
    int credits = 0;
    static final int minCredits = 12;
    static final int maxCredits = 18;
    boolean overloadAuthorized = false;
    ArrayList schedule = new ArrayList();

    static String url = "jdbc:odbc:Reggie";
    static { try { Class.forName("sun.jdbc.odbc.JdbcOdbcDriver"); }
             catch (Exception ignored) {} }

    public static void deleteAll() throws Exception {
        Connection conn = null;

        try {
            conn = DriverManager.getConnection(url, "", "");
            Statement statement = conn.createStatement();

            statement.executeUpdate("DELETE * FROM schedule;");
        } finally {
            try { conn.close(); } catch (Exception ignored) {}
        }
    }

    public static Schedule create(String name) throws Exception {
        Connection conn = null;
        try {
            conn = DriverManager.getConnection(url, "", "");
            Statement statement = conn.createStatement();

            statement.executeUpdate(
               "DELETE FROM schedule WHERE name = '" + name + "';");
            return new Schedule(name);
        } finally {
            try { conn.close(); } catch (Exception ignored) {}
        }
    }

    public static Schedule find(String name) {
        Connection conn = null;

        try {
            conn = DriverManager.getConnection(url, "", "");
            Statement statement = conn.createStatement();
            ResultSet result = statement.executeQuery(
                "SELECT * FROM schedule WHERE Name= '" + name + "';");

            Schedule schedule = new Schedule(name);

            while (result.next()) {
                int offeringId = result.getInt("OfferingId");
                Offering offering = Offering.find(offeringId);
                schedule.add(offering);
            }

            return schedule;
        } catch (Exception ex) {
            return null;
        } finally {
            try { conn.close(); } catch (Exception ignored) {}
        }
    }

    public static Collection all() throws Exception {
        ArrayList result = new ArrayList();
        Connection conn = null;

        try {
            conn = DriverManager.getConnection(url, "", "");
            Statement statement = conn.createStatement();
            ResultSet results = statement.executeQuery(
                "SELECT DISTINCT Name FROM schedule;");

            while (results.next())
                result.add(Schedule.find(results.getString("Name")));
        } finally {
            try { conn.close(); } catch (Exception ignored) {}
        }

        return result;
    }

    public void update() throws Exception {
        Connection conn = null;

        try {
            conn = DriverManager.getConnection(url, "", "");
            Statement statement = conn.createStatement();

            statement.executeUpdate(
                 "DELETE FROM schedule WHERE name = '" + name + "';");

            for (int i = 0; i < schedule.size(); i++) {
                Offering offering = (Offering) schedule.get(i);
                statement.executeUpdate(
                     "INSERT INTO schedule VALUES('" + name + "','"
                     + offering.getId() + "');");
            }
        } finally {
            try { conn.close(); } catch (Exception ignored) {}
        }
    }

    public Schedule(String name) {
        this.name = name;
    }

    public void add(Offering offering) {
        credits += offering.getCourse().getCredits();
        schedule.add(offering);
    }

    public void authorizeOverload(boolean authorized) {
        overloadAuthorized = authorized;
    }

    public List analysis() {
        ArrayList result = new ArrayList();

        if (credits < minCredits)
            result.add("Too few credits");

        if (credits > maxCredits && !overloadAuthorized)
            result.add("Too many credits");

        checkDuplicateCourses(result);

        checkOverlap(result);
        return result;
    }

    public void checkDuplicateCourses(ArrayList analysis) {
        HashSet courses = new HashSet();
        for (int i = 0; i < schedule.size(); i++) {
            Course course = ((Offering) schedule.get(i)).getCourse();
            if (courses.contains(course))
               analysis.add("Same course twice - " + course.getName());
            courses.add(course);
        }
    }

    public void checkOverlap(ArrayList analysis) {
      HashSet times = new HashSet();

      for (Iterator iterator = schedule.iterator();
          iterator.hasNext();)
      {
          Offering offering = (Offering) iterator.next();
          String daysTimes = offering.getDaysTimes();
          StringTokenizer tokens = new StringTokenizer(daysTimes, ",");
          while (tokens.hasMoreTokens()) {
              String dayTime = tokens.nextToken();
              if (times.contains(dayTime))
                  analysis.add("Course overlap - " + dayTime);
              times.add(dayTime);
          }
      }
    }

    public String toString() {
        return "Schedule " + name + ": " + schedule;
    }
}