Happy Days are Here. Finally. 151 :)

[Mark Spritzler]

Wow, I finally got my results. I had to call them up on Friday to find out that the testing site I took the essay exam at didn't send it in to SunEd till 8 days later. So they put a rush on the results.
But it was still worth the wait.
My score was 151/155, here is the only thing they have posted.
Test: Sun Certified Developer for the Java 2 Platform (310-027)
Date Taken: 2001-12-18 09:12:10.250
Grade: P
Score: 151
Comment:
If you need to resubmit your assignment, return to the test history screen, press the 'Assignments' button, and follow the instructions.

I wonder why they didn't break down the parts. Oh well
I did not use the LockManager Class design pattern that Peter knows really well. I think that might have helped my score to use it. I also had the Search Criteria support methods in the Data Class. Like putting the search string into a hashtable, I should have put that in my CriteriaBuilder class instead.
Otherwise I used all the great brilliant Ideas that are posted here at Javaranch. This is the best place. Thank you Peter, Gennady, James Kwan, Marlon, Farouk, and Terry McKee. And anyone else now and in the past who have posted great questions, and also for letting me answer some of those, without you saying, "What are you talking about!, get out of here."
I'd also like to thank my mom and dad, my director, producer, fellow cast members and to my agent. Just kidding.
Mark
[This message has been edited by Mark Spritzler (edited December 18, 2001).]

[Levent Tinaz]

Great. Good luck Mark.
What kind of questions are they asking in the exam ?

[Terry McKee]

Congratulations!
I bet it feels really great to be done! What are your plans now?

[Mark Spritzler]

Levent: The essay question are about your decisions on your design. Did you pick RMI or Serialization and Why? How did you pick your nose when you made the GUI? stuff like that.
Terry: I have started studying for the SCJ Web Developer exam. I hear it is easy, and just one test, and that you get the results immediately. Also less expensive than Architect. Then after Web, I will do Architect.
Mark

[Bal Sharma]

Great Score! Congratulations. Good luck! -Bal

[srinath anand]

Mark-congrats great score!
Could you possibly tell me the gui u used and also the algorithm for the criteriaFind?

[Gennady Shapiro]

Dont you wish they would tell you what they take points off though?
Great score! (go to your boss demand a raise)

[Ian B Anderson]

Well done Mark, and good luck with the Web Developer.
Ian

[James Kwan]

Mark,
Great Job! What a great Xmas gift! Glad your wait is finally over. Now you can hop onto the band wagon with us as we ride into the SCWCD.
Jim

[Mark Spritzler]

Thanks Bal.
Gennady: Yes that would be cool, but I don't even know what sections they took off. It just gave my the final score and no breakdown. But I think I know why. I modified the Data class. enough said.
Thanks Ian
James, meet you at the Web Developer Forum.
Srinath: I used the GridBagLayout manager. I had three JComboboxes with the origin airport, departure airport and airlines filling the lists in the comboboxes. I added "Any" as the first selection in all three.
Underneath the comboboxes was a Search JButton. Below that the JPanel which held the JTable, to display the results. Select a flight in the JTable, and underneath you can enter the number of seats to book. Next to the JTextField for number of seats, I had a Book Flight JButton.
That was it. Oh, I had a file Menu that had Exit underneath it, and a Help menu with user HTML help.
For SearchCriteria. I had a CriteriaBuilder class that would take the make the criteriaString from the JComboboxes. I should have had it also return a Hashtable with the search selection. Instead I put that method in my Data class. I looped through the entire database, and if the current record matched the criteria, I put the record into a DataInfo[] array. And returned the array.
Hope that helps.
Mark

[Arvind.Popli]

Congratulations, Mark
-Arvind

[Marlon Bravo]

Congratulations Mark. It's great that you're finally on board. We knew it was just a matter of time. Now , we can all concentrate for the SCWCD. With your EJB experience, it should be a piece of cake.
After SCWCD, I'm planning to work on IBM's xml cert. Is thing something you might be interested in? And thanks for that tip on the EJB class.
- marlon

[Donald Wedding]

Way to go Mark! Great score!
You gonna hang around this group for a while and help us out or are you moving on to the SCJA forum?

[Andre Tow]

Congratulations! =)
------------------
Andre Mermegas
Sun Certifed Java Programmer

[Mark Spritzler]

Marlon: I am not to hip with XML. I try to avoid it as much as possible. Enjoy the class and Hatem, if you sign up.
Donald: Of course, I'll stick around and help out as best as I can. And You can also find me at the Web Developer Forum.
Mark

[Charu Krishnan]

Great Mark. Great score and congrats. It was worth the waiting I guess.
I am also palnning to do the web developer exam, so see you at that forum
Charu

[James Kwan]

What do you think of the JCert? Will you be pursuing that in the near future? Congrats again...
Jim

[Farouk Mohamed1]

Hi Mark
All your wait is over. Congratulations, hope you will get onto something exciting like this very soon. I would love to submit my applciation soon as well got very busy suddenly. Thanks for you valuable replies as well....
Great score !!!11
Farouk

[Mark Spritzler]

Originally posted by James Kwan:
What do you think of the JCert? Will you be pursuing that in the near future? Congrats again...
Jim

Actually, I don't know what JCert is? I thought that was the Sun Certifications. Is it somone elses certification?
Mark

[Donald Wedding]

JCert is a different certification path that Sun came up with. I don't think it caught on like they had anticipated.
Here's a link to check it out.
http://www.jcert.org/
By the way, how can we get a JCERT forum here in the Saloon?

[Mark Spritzler]

Nah, I don't think I'll do the JCert. I have already used Weblogic 5.1, and have a certificate for completing their build enterprise applications with EJB and Weblogic 5.1 class.
But the JCert seems to be too much work and hassle. I'll stick with Sun Web Developer and Architect certs and stop there.
I am looking at the certifications as more of a great learning process. It gets your feet into the areas, when yuo can't get that experience at your current employer
Mark

[Anurag Mishra]

Use setEnabled(true) insted of setVisible, i think so it is more suitable way.
Regards
Anurag Mishra

[Eric Li]

Congradulation! Mark! I have a question about packaging.
I plan to incude the classes for database and server_stub in the client.jar and include the classes for database in the server.jar. This way I don't need the classpath from the command line to avoid the environment setup. In your opinion, do you think this is acceptable to this assignment? And what's your packaging strategy? Thanks in advance!
Eric

[Mark Spritzler]

Well besides the obvious Client files. GUI/Controller, etc. I also included the _skel and _stub files for the ConnectionFactory, and the DataAccessRemote classes, in a client.jar file. This was an executable jar file. so to run they command line is;
java -Djava.security.policy=policy.all -jar client.jar <<parameters>>
I also had a server.jar which was started by:
java -Drmi.security.policy=policy.all -jar server.jar
I packaged the 2 jars, along with all the javadoc, images, readme.txt, design.txt, and source code into the submission jar.
Mark

[Eric Li]

Thanks! Mark. This helped me a lot and made me feel more comfortable to stick to my original plan. I just don't want my submission to be failed because of this classpath thing or just my way of packaging.
Eric

[Mark Spritzler]

Eric. I know what you mean, I was worried about that too. So the way to ease you worry, is to test, test and then test. Take your submission and put it on another machine, unpack it, and try to run your app. If it works, try another machine, if that works, then I think you are good.
Mark

[Steven Xu]

Wow, It is an impressive score!
Mark, I have a quick question for you. In the "Overall architecture" section, it says "The user must be able to select
the operating mode..." how did you handle this?
Thank you!
Steven

[Mark Spritzler]

Well in my main of the client. I check to see if there is any args passed. IP address/URL of server for remote mode, or no arguments for local mode.
The main then calls an overloaded method in my DataAccessFactory class called getDataAccess. one of the method takes a IP/URL for the server and calls on rmi to lookup the connectionFactory on the server calls getConnection which returns a DataAccessRemote class. The other method takes no arguments, and returns a DataAccessLocal class
Both remote and local classed implements my DataAccess Interface. blah blah blah.
Hope that answers the question
Mark

[Steven Xu]

Thank you! I got it.

[Mathew Sam]

Congrats Mark.After a long wait you got it.
I have some doubts.
1) Do we need to use dynamic class loading?
2) If there is no dynamic loading,do we need to set the security manager in the server class or do we need to use the policy file?

Sam

[Anonymous]

Congratulations!!!
What coding standards did you use?

[Mark Spritzler]

No you don't need to use dynamic loading.
As far as a policy file. I used a simple one that gave full access.
I used the RMISecurityManager in the client only. I used it in the DataAccessFactory, which is actually in the db package, but used by the client.
Hope that helps
Mark

[Yanjing Liu]

Hi Mark,
Great Score! Congratulations for passing the exam.
I am about ready to submit my project to Sun. The only problem I seem to have now is locking the whole DB.
Please do share your experience regarding locking the whole DB.
I will be extremely thank full to you for any feed back
Yanjing

Originally posted by Mark Spritzler:
Wow, I finally got my results. I had to call them up on Friday to find out that the testing site I took the essay exam at didn't send it in to SunEd till 8 days later. So they put a rush on the results.
But it was still worth the wait.
My score was 151/155, here is the only thing they have posted.
Test: Sun Certified Developer for the Java 2 Platform (310-027)
Date Taken: 2001-12-18 09:12:10.250
Grade: P
Score: 151
Comment:
If you need to resubmit your assignment, return to the test history screen, press the 'Assignments' button, and follow the instructions.

I wonder why they didn't break down the parts. Oh well
I did not use the LockManager Class design pattern that Peter knows really well. I think that might have helped my score to use it. I also had the Search Criteria support methods in the Data Class. Like putting the search string into a hashtable, I should have put that in my CriteriaBuilder class instead.
Otherwise I used all the great brilliant Ideas that are posted here at Javaranch. This is the best place. Thank you Peter, Gennady, James Kwan, Marlon, Farouk, and Terry McKee. And anyone else now and in the past who have posted great questions, and also for letting me answer some of those, without you saying, "What are you talking about!, get out of here."
I'd also like to thank my mom and dad, my director, producer, fellow cast members and to my agent. Just kidding.
Mark
[This message has been edited by Mark Spritzler (edited December 18, 2001).]

[Mark Spritzler]

You can find my solution for Entire Database lock in this forum link
http://www.javaranch.com/ubb/Forum25/HTML/001628.html
Mark

[Yanjing Liu]

Mark,
Thanks for your replies.
I have code as follows for implementing the locking whole database:
private Map lockHash = new HashMap(); //Global declaration
public void lock(int record, Object lock) throws IOException{
if (record == -1) {
for (int i = 1; i <= recordCount; i++){
lock(i, lock);
}
}else {
synchronized(lockHash) {
while((lockHash.containsKey(new Integer(-1)) | | lockHash.containsKey(new Integer(record))) {
try {
lockHash.wait();
} catch (InterruptedException e) {
throw new IOException("lock failed ");
}
}
lockHash.put(new Integer(recno), lock);
}
}
I will really appreciate if you can point me a better way of implementing it?
Thanks,
Yanjing

Originally posted by Mark Spritzler:
You can find my solution for Entire Database lock in this forum link
http://www.javaranch.com/ubb/Forum25/HTML/001628.html
Mark

[Mark Spritzler]

In your code it looks like you have a Lock object. I did not have anything like that. The rest f the code pretty much looks exactly what I had. You do not need the throw new IOException. The lock did not fail, it was in a wait state, then it got the lock, to me that is success.
Also try not to use Magic Numbers, like -1 in code. Instead you can make a constant with that value. Say:
<CODE>
private static final int LOCK_ALL_RECORDS = -1;
</CODE>
In your while statement you have lockHash.containsKey(new Integer(-1)) as the first part. You do no need this because if someone has a database lock then all the record numbers are already in the HashMap and anyone trying to get any lock will be put into the wait state either way.
Hope that helps.
Mark

[Yanjing Liu]

Happy New Year Mark!
Thanks for your quick reply. I revised my code as you suggested. It works. Thank you for your kind help.
Mark, I have another two questions and you may be able to help me again.
After successfully lock the whole database,
1. What approach did you take to inform the user that the database is closed?
2. How did you unlock the whole database?
Looking forward to hearing from you again.
Yanjing

[Mark Spritzler]

The only person who ever locked the entire database was the server, and that was so that it could shutdown. I never had to unlock the entire database, not part of the requirements. And if a client was still up and in remote mode, then the next request to the server would cause a DatabaseException, which my GUI would receive and inform the user that the Database was not available.
This works if you chain all your exceptions to the client. Well, except server side exceptions for the server's mistakes.
Meaning if the server started up and couldn't find the db.db file, the client would never receive such an exception, as it is meant for the server. But any problems that client needed to know, it was chained up there, and I had each one call a method that basiccaly set up a JOptionPane to display the method.
Hope that helps.
If you have any more questions, maybe we should post it as a new thread, so others can see them, and also since there are too many posts in this thread already.
Thanks
Mark