The code is at
http://java.sun.com/developer/onlineTraining/new2java/divelog/part5/DiveHandler.java

my copy in Kawa has extra white space at the top,so line 204 is
Dr = (DiveRecord) input.readObject();

The DiveRecord class is

//Represents a record of a dive
package divelog;
import java.io.*;
import java.io.Serializable;

public class DiveRecord implements Serializable
{
 //Instance variables
   private String date, type, cts;
   private int depth, start, end, used,
                        time, count, vis;
   public DiveRecord ()
   {
      setDive();
   }
   public void setDive()
   {
       type = "";
       date = "00/00/00";
       depth = 00;
       start = 0000;
       end = 0000;
       used = 0000;
       time = 00;
       count = 000;
       vis = 00;
       cts = "";
   }

   public void setDive (
               String t,String d, int dth,
               int s, int e, int u, int bt,
                  int c, int v, String cts)
   {

       this.type = t;
       this.date = d;
       this.depth = dth;
       this.start = s;
       this.end = e;
       this.used = u;
       this.time = bt;
       this.count = c;
       this.vis = v;
       this.cts = cts;

   }

   public String toString()
   {
      return type + date + depth + start +
         end + used + time + count + vis + cts;
   }

   public String getDte()
   {
     return date;
   }
   public int getDepth ()
   {
     return depth;
   }
   public String getType ()
   {
     return type;
   }
   public int getStart ()
   {
     return start;
   }
   public int getEnd ()
   {
     return end;
   }

   public int getUsed ()
   {
     return used;
   }
   public int getTime()
   {
     return time;
   }
   public int getCount ()
   {
     return count;
   }
   public int getVis()
   {
     return vis;
   }
   public String getComments()
   {
     return cts;
   }

}

It's hard to make this self-contained and small. DiveHandler is called by
another class which calls several classes.  I'll work on it.
Ralph

The DiveHandler class is at
http://java.sun.com/developer/onlineTraining/new2java/divelog/part5/DiveHandler.java
as far as I can tell, the file is written to by
output.writeObject (Dr);
             output.flush();
How do you get printStackTrace to give a reason for the error?  The examples
I saw in google often had a reason in the first line.
Ralph

It is both confusing and irritating when you violate coding
conventions like variables begin with lower case and classes upper
case. It is particularly important to follow them when posting
snippets.

I wish Javac would mark violations at least with warnings.

see http://mindprod.com/jgloss/codingconventions.html

--
Canadian Mind Products, Roedy Green.
Coaching, problem solving, economical contract programming.
See http://mindprod.com/jgloss/jgloss.html for The Java Glossary.