passed 144/155

Hey guys, just wanted to pass this on. I took the exam on 6/9 and got the results today. Thanks for all your help. This board has been great.
Grade: P
Score: 144
Comment: This report shows the total points that could have been awarded in each section and the actual number of points you were awarded. This is provided to give you per-section feedback on your strengths. The maximum possible # of points is 155; the minimum to pass is 124.

General Considerations(maximum = 58): 51
Documentation(maximum = 20): 16
GUI(maximum = 24): 24
Server(maximum = 53): 53
To answer the basic questions:
I used RMI.
I did not track the client locking database records.
I used combo boxes to select airports on the client.
My Data class and RemoteServer implemented a common adapter interface.
My booking and airport retrieval logic was in a client side class, which made calls against my adapter interface.

Thanks again,
Matt

My Congratulations on your achievement.
I have a small question. What are the permissions you set in the server policy file ? did u give all permission ?
Thanks,
Ravi.

Yes, I granted all permissions.

congratulaions. that is great score. All the best for the future.
Your Friendly Bartender
shailesh.

Thanks for the reply.
One more question is :
If I run my client on Linux, it gives me bunch of errors like this.
I tried setting the default lookandfeel. but no use..
Will this be of any hindrance for the exam ?
Font specified in font.properties not found [--symbol-medium-r-normal--*-%d-*-*-p-*-adobe-fontspecific]
Thanks,
Ravi.

I never ran my project on Linux so I can't comment on your problem. You'll probably be fine as long as you followed the instructions to only use a production release of Java 2 without anything that would require an IDE to execute the program.

Matt,
I have a small quetion about your solution. Did you make your booking method threaded? If so how did you handle updating the JTable seats available after a requested booking is successful.
Thanks,
Dave

Hi Matt,
Congrats on becoming java developer. I just have a doubt regarding the Data class. Can we change the defintion of Data class. Meaning can I do something like this ?
interface DBInterface
{}
class Data implements DBInterface
{
}

Vivian,
I can be brief: yes.
- Peter

David,
No, my book flight method was not threaded. It just calls lock, read, modify and unlock. The only solutions to your problem that I can think of are to either have the server callback the client after the booking completes, poll the server at regular intervals, or have the completion of the booking trigger some kind of event that causes a listner thread to poll the server.
Vivian,
I can confirm what Peter said. I changed the definition of my Data class in a similar fashion.

Matt,
One more question for you. I have written my lock/unlock methods and currently I am storing locks in a Vector and syncronizing on that. I am concerned that the performance of this method will be poor because if 2 threads trying to lock two seperate rows in the db will still have to wait on each other since they are waiting to syncronize the vector. I was considering creating a seperate class to store the locks and syncing on the class storing the locks. I don't know if this makes sense but if you could just tell me if either of these two methods sounds similar to your lock/unlock methods.
Thanks,
Dave

David,
I didn't think that synchronizing on the Vector was the best idea, but many people here used it with success.
I don't know exactly what you meant by your second method, but it could be similar to the one I used. I created a List that was the size of the number of records in my database. I filled the list with mutable boolean objects which indicated whether or not the record was locked. Then, I synchronized on those objects.
My method does create some overhead in keeping a list of locked records. However, a boolean is very small so even a large number of wrapper objects shouldn't take up much memory. Adding objects to keep track of inserted records doesn't take much time either. The advantage is that clients don't have to wait for each other when they are trying to lock different records. More importantly, clients who are only interested in one record don't get woken up every time any record is unlocked.
Either of the methods you are talking about have been used successfully.
Matt