isOverlap method problems

[John Jordan John Jordan]

Hi:
I trying to invoke an isOverlap method from within a Calendar class. The Timespan method tests for overlapping appointments.
The error message I get is:
java:114: Incompatible type for method. Can't convert Appointment to Timespan.
if (theDuplicates.isOverlap(nextApp))
What is the problem and how do I correct the problem and accomplish the my goal?
Thanks.

/**
Describes a calendar for a set of appointments.
@version 1.0
*/
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.Vector;
import java.io.*;
public class CalendarTest
{  public static void main(String[] args)
   {  try
      {  InputStreamReader reader 
            = new InputStreamReader(System.in);
         BufferedReader console 
            = new BufferedReader(reader);
            
          Calendar markCalendar = new Calendar("Mark");  
               
         System.out.println("Please enter an appointment startdate and time:");
         String input1 = console.readLine();
         String sTime = input1;
            
         System.out.println("Please enter an appointment enddate and time:");  
         String input2 = console.readLine();
         String endTime = input2; 
         
         System.out.println("Please enter an appointment description:");  
         String input3 = console.readLine();
         String description  = input3; 
                
         markCalendar.addApp(new Appointment(sTime, endTime, description));
                         
         markCalendar.print();
         
         
      
         }
         catch(IOException e)
         {  System.out.println(e);
            System.exit(1);
         }  
      
               
   }
}
/**
Describes a calendar for a set of appointments.
*/
class Calendar
{      
  
   /**
   Constructs a calendar.
   */   
   public Calendar(String aName)
   {  name = aName;
      appointments = new Vector();
   }
   
   
   /**   
   Adds an appointment to this Calendar.
   @param anApp The appointment to add.
   */
   public void addApp(Appointment anApp)
   {   
      
      appointments.add(anApp); 
      
   }
   
   /**
   Removes an appointment from this Calendar.
   @param anApp The appointment to be removed.
   */
   
   public void removeApp(Appointment toFind)
   {       
      for ( int i = 0; i < appointments.size(); i++)
      {     
         if (((Appointment)appointments.get(i)).equals(toFind))
         {
          
             appointments.remove(i);
         }
      } 
           
   }
   
   /**
   Tests for duplicate appointment dates.
   */
   public void dupsTest()
   { 
      for (int x = 0; x < appointments.size(); x++)
      {
         Appointment check = (Appointment)appointments.get(x);
         for (int y = appointments.size()-1; y > x; y --)
         {  
            Appointment nextApp =(Appointment) appointments.get(y);
            
            
            if (theDuplicates.isOverlap(nextApp))
            {  System.out.println("Duplicate appointments: ");
               check.print();
               nextApp.print();
            }
            
         } 
             
      }
             
   }  
   
   /**
   Prints the Calendar.
   */
   public void print()
   {  System.out.println(name + "               C A L E N D A R");
       
      System.out.println();
    
  System.out.println("Starttime               EndTime       " +
           "      Appointment");
             
        
      for (int i = 0; i < appointments.size(); i++)
      {  Appointment nextApp =(Appointment) appointments.get(i);
         nextApp.print();
      }
      
            
   }
   
   private Vector appointments;
   private String name;
   private Appointment theAppointment;
   private Timespan theDuplicates;
}
/**
Describes an appointment.
*/
class Appointment 
{  
   public Appointment(String aStarttime,String aEndtime, String aApp)
   {  //date = aDate;
      starttime = aStarttime;
  endtime = aEndtime;   
      app = aApp;
   }
 
 /**
 Method to test whether on object equals another.
 @param otherObject  The other object.
 @return true if equal, false if not
*/
 
 public boolean equals(Object otherObject)
 {
      if (otherObject instanceof Appointment)
      {  Appointment other = (Appointment)otherObject;
                  
         return (date.equals(other.date) && starttime.equals(other.starttime)
                 && endtime.equals(other.endtime) && app.equals(other.app));
      }   
      
       else return false;
      
 } 
 
 
 /**
 Method to test whether part of an object equals another.
 @param otherObject  The other object.
 @return true if equal, false if not
 */
 
 public boolean match(Object otherObject)
 {
    if (otherObject instanceof Appointment)
     {  Appointment other = (Appointment)otherObject;
                 
        return (date.equals(other.date) && starttime.equals(other.starttime)
                && endtime.equals(other.endtime));
     }   
     
      else return false;
      
} 
      
   /**
   Prints the Starttime, Endtime and a description of the
   appointment.
   */
   public void print()   
   {  System.out.println();
      System.out.println(starttime + "       " + endtime 
     + "     " + app );
      System.out.println();
                 
   }
   
   private String date;
   private String starttime;
   private String endtime;
   private String app;
   
   
 
    public class Timespan 
{
     private Date _start;
     private Date _end;
     private static final String PARSE_FORMAT = "dd/MM/yy hh:mm a";
     public Timespan(String start, String end)
     {
         SimpleDateFormat df = new SimpleDateFormat(PARSE_FORMAT);
         try
         {
             _start = df.parse(start);
             _end = df.parse(end);
         }
         catch (ParseException e)
         {
             e.printStackTrace();
         }
     }
     public Date getStart()
     {
         return _start;
     }
     public Date getEnd()
     {
         return _end;
     }
     public boolean isOverlap(Timespan anotherTs)
     {
         long thisStart = _start.getTime();
         long thisEnd = _end.getTime();
         long anotherStart = anotherTs.getStart().getTime();
         long anotherEnd = anotherTs.getEnd().getTime();
         if ((thisStart > anotherEnd) || (thisEnd < anotherStart))
             return false;
         else
             return true;
     }
  }
}

(edited by Cindy to format code using [ code] and [ /code] tags without the spaces)
[ January 21, 2003: Message edited by: Cindy Glass ]