www.pudn.com > SRS.rar > ScheduleOfClasses.java

// ScheduleOfClasses.java - Chapter 16 version. 
 
// Copyright 2000 by Jacquie Barker - all rights reserved. 
 
// A MODEL class. 
 
 
import java.util.*; 
 
public class ScheduleOfClasses extends CollectionWrapper { 
	//------------ 
	// Attributes. 
	//------------ 
 
	private String semester; 
 
	// This Hashtable stores Section object references, using 
	// a String concatenation of course no. and section no. as the 
	// key, e.g., "MATH101 - 1". 
 
	private Hashtable sections;  
 
	//---------------- 
	// Constructor(s). 
	//---------------- 
 
	public ScheduleOfClasses(String semester) { 
		setSemester(semester); 
		 
		// Instantiate a new Hashtable. 
 
		sections = new Hashtable(); 
	} 
 
	//----------------- 
	// Get/set methods. 
	//----------------- 
 
	public void setSemester(String semester) { 
		this.semester = semester; 
	} 
 
	public String getSemester() { 
		return semester; 
	} 
 
	//----------------------------- 
	// Miscellaneous other methods. 
	//----------------------------- 
 
	// Used for testing purposes. 
	 
	public void display() { 
		System.out.println("Schedule of Classes for " + getSemester()); 
		System.out.println(""); 
 
		// Step through the Hashtable and display all entries. 
 
		Enumeration e = sections.elements(); 
 
		while (e.hasMoreElements()) { 
			Section s = (Section) e.nextElement(); 
			s.display(); 
			System.out.println(""); 
		} 
	} 
 
	public void addSection(Section s) { 
		// We formulate a key by concatenating the course no. 
		// and section no., separated by a hyphen. 
 
		String key = s.getRepresentedCourse().getCourseNo() +  
			     " - " + s.getSectionNo(); 
		sections.put(key, s); 
 
		// Bidirectionally hook the ScheduleOfClasses back to the Section. 
 
		s.setOfferedIn(this); 
	} 
 
	public void parseData(String line) { 
		// We're going to parse tab-delimited records into 
		// six attributes -- courseNo, sectionNo, dayOfWeek,  
		// timeOfDay, room, and capacity.  We'll use courseNo to  
		// look up the appropriate Course object, and will then 
		// call the scheduleSection() method to fabricate a 
		// new Section object. 
 
		// First, make a copy of the record. 
 
		String restOfLine = line; 
		int index = restOfLine.indexOf("\t"); 
		String courseNo = restOfLine.substring(0, index); 
		restOfLine = restOfLine.substring(index+1); 
		index = restOfLine.indexOf("\t"); 
 
		// We have to parse the next value as a number. 
		String sectionNumber = restOfLine.substring(0, index); 
		int sectionNo = Integer.parseInt(sectionNumber); 
		restOfLine = restOfLine.substring(index+1); 
 
		index = restOfLine.indexOf("\t"); 
		String dayOfWeek = restOfLine.substring(0, index); 
		restOfLine = restOfLine.substring(index+1); 
		index = restOfLine.indexOf("\t"); 
		String timeOfDay = restOfLine.substring(0, index); 
		restOfLine = restOfLine.substring(index+1); 
		index = restOfLine.indexOf("\t"); 
		String room = restOfLine.substring(0, index); 
		 
		// We have to parse the last value as a number. 
		String capacityValue = restOfLine.substring(index+1); 
		int capacity = Integer.parseInt(capacityValue); 
 
		// Look up the Course object in the Course Catalog. 
		// Having made courseCatalog a public static attribute 
		// of the SRS class comes in handy! 
		Course c = SRS.courseCatalog.findCourse(courseNo); 
 
		// Schedule the Section. 
		Section s = c.scheduleSection(sectionNo, dayOfWeek.charAt(0),  
					      timeOfDay, room, capacity); 
		String key = courseNo + " - " + s.getSectionNo(); 
		addSection(s); 
	} 
 
	// The full section number is a concatenation of the 
	// course no. and section no., separated by a hyphen; 
	// e.g., "ART101 - 1". 
 
	public Section findSection(String fullSectionNo) { 
		return (Section) sections.get(fullSectionNo); 
	} 
 
	// We don't need this method, but we have to provide it because 
	// we inherited an abstract signature. 
 
	public void parseData2(String line) { } 
 
	// This next method was added for use with the GUI. 
 
	// Convert the contents of the Hashtable into a Vector 
	// that is sorted in alphabetic order. 
 
	public Vector getSortedSections() { 
		Vector sortedKeys = new Vector(); 
		Vector sortedSections = new Vector(); 
 
		// Note that we can pull the keys as an Enumeration as 
		// well as the objects themselves. 
 
		Enumeration e = sections.keys(); 
		while (e.hasMoreElements()) { 
			boolean inserted = false; 
			String key = (String) e.nextElement(); 
			for (int i = 0; i < sortedKeys.size(); i++) { 
				String val = (String) sortedKeys.elementAt(i); 
 
				// The compareTo() method compares two Strings, 
				// returning a negative value if "key" comes 
				// alphabetically before "val", zero if  
				// they are equal, and a positive value if  
				// "key" comes alphabetically after "val". 
 
				if (key.compareTo(val) <= 0) { 
					sortedKeys.insertElementAt(key, i); 
					inserted = true; 
					break; 
				} 
			} 
 
			// If it hasn't been inserted yet, stick it at the end 
			// of the "sortedKeys" Vector. 
 
			if (!inserted) sortedKeys.add(key); 
		} 
 
		// Now that "sortedKeys" Vector contains all of the KEYS in  
		// alphabetic order, we'll step through that Vector and use  
		// it to pull the Section objects themselves out of the  
		// Hashtable and into another Vector "sortedSections". 
 
		for (int i = 0; i < sortedKeys.size(); i++) { 
			String key = (String) sortedKeys.elementAt(i); 
			Section s = (Section) sections.get(key); 
			sortedSections.add(s); 
		} 
 
		return sortedSections; 
	} 
}