1)In non-network mode, we were told " the database and GUI must run in the same VM and must perform no networking".
Does that means that in this mode, two separate programs each containg a main() method(one is database manager, another is GUI)must start and run in the same VM? If this is case, how do they communicate?
Can i just run one program(the client GUI) to read the database files instead of database manager when running under non-network mode?
2)Since the assignment only require us to implement search and book functionality, when should we use the methods "update(..)" and "delete(..)"?
3)If a customer book a record, following is what I think I should implement. Is that correct?
==Add another record to the same database, it's same to the record the ==customer is booking instead of cusotmer id.
4)Can anyone tell me some tutorial about jtable? I do not know how to select a record in the jtable to implement the booking functionality.
SCJP 1.2, OCP 9i DBA, SCWCD 1.3, SCJP 1.4 (SAI), SCJD 1.4, SCWCD 1.4 (Beta), ICED (IBM 287, IBM 484, IBM 486), SCMAD 1.0 (Beta), SCBCD 1.3, ICSD (IBM 288), ICDBA (IBM 700, IBM 701), SCDJWS, ICSD (IBM 348), OCP 10g DBA (Beta), SCJP 5.0 (Beta), SCJA 1.0 (Beta), MCP(70-270), SCBCD 5.0 (Beta), SCJP 6.0, SCEA for JEE5 (in progress)
As you said for question 1), The 2 programs can be communicated via direct method calls. I am still not understanding your answer to my first question.
Say I have a client gui called Client.java and a data manager called Data.java. If I start them separatly both on the same local java VM like:
java Client --- start client gui
java Data --- start data manager
Is this the way to start the non-network mode of the client gui and data manger. I doubt these two programs can communicate by direct method calls, since both of them have a sperate thread running from their own main() method.
Back to my question 3), My understanding to your explanation is that the total number of records in the database is not changed. When a customer book a record, only the customer id is changed. Is that right? In this case, if one customer book a record, no other customer can book the same record in the future, is that right?
SCJP 1.2, OCP 9i DBA, SCWCD 1.3, SCJP 1.4 (SAI), SCJD 1.4, SCWCD 1.4 (Beta), ICED (IBM 287, IBM 484, IBM 486), SCMAD 1.0 (Beta), SCBCD 1.3, ICSD (IBM 288), ICDBA (IBM 700, IBM 701), SCDJWS, ICSD (IBM 348), OCP 10g DBA (Beta), SCJP 5.0 (Beta), SCJA 1.0 (Beta), MCP(70-270), SCBCD 5.0 (Beta), SCJP 6.0, SCEA for JEE5 (in progress)
(David) Back to my question 3), My understanding to your explanation is that the total number of records in the database is not changed. When a customer book a record, only the customer id is changed. Is that right? In this case, if one customer book a record, no other customer can book the same record in the future, is that right?
[bold](Nick)YES.[/bold]
Bing:
I think Nick was "Yes"ing to the first question.
David:
Does that means that in this mode, two separate programs each containg a main() method(one is database manager, another is GUI)must start and run in the same VM?
Nicholas:
YES.
David:
Can i just run one program(the client GUI) to read the database files
Bing:
I am sorry to say that you may not get that much help here if you don't understand Nick's answer to your first question.
(...)
This forum is a great place to discuss SCJD issues but I never see its purpose is to help SCJD takers to deal with nitty gritty stuff like how to select a record from a jtable.
Bing:
The second question from David is a design issue according to some discussions in the past.
I've found a lot of discussions ever since I was told to do a search on topics that I wanted to know
2. The instructions in the document tell you what specific piece of funtionality you need to implement for your assignment. Mostly it would be booking() and searching() for a set of records. This is the functionality that is provider to the end-user using the application, but
the instructions also require us to implement all the functionality create, delete, update, read, find etc in the Data Access Layer ....The end-user of the application may not use all this functionality, but we have to implement them. Maybe client programs developed in the future could use this functionality on the server side.
Originally posted by Guvenc Gulce:
Does SCJD have some expiration period like SCJP.
My SCJP will expire in 5 months. Does that mean I can
not take SCJD anymore and I have to take SCJP once more ?
Why expiration date ? Does the java language change
drasticly every two year ?
Co-author of SCMAD Exam Guide, Author of JMADPlus
SCJP1.2, CCNA, SCWCD1.4, SCBCD1.3, SCMAD1.0, SCJA1.0, SCJP6.0
Originally posted by Guvenc Gulce:
I want to keep the things simple during my implementation
and just want to do the things that are really necesssary (must)
I saw during browsing in the forum that more than one people
actually managed to get SCJD without implementing create / delete
methods. They are not used anywhere and there is nothing in
the assigment that implies that these methods need to be implemented.
But I still see in some posts that it is still being strongly adviced
to implement them by some guys in this forum. Why ?
Why should I implement them, if I can pass it withoud doing so
and when I have examples(guys passed without implementing) in
front of me ? (see this post)
Originally posted by david hu
1)In non-network mode, we were told " the database and GUI must run in the same VM and must perform no networking".
Does that means that in this mode, two separate programs each containg a main() method(one is database manager, another is GUI)must start and run in the same VM? If this is case, how do they communicate?
Originally posted by Nicholas Cheung
YES.
Originally posted by Philippe Maquet:
The answer is NO. Any Java application has one and only *one* main method.
Originally posted by Bing Yuen
I am sorry to say that you may not get that much help here if you don't understand Nick's answer to your first question.
(...)
This forum is a great place to discuss SCJD issues but I never see its purpose is to help SCJD takers to deal with nitty gritty stuff like how to select a record from a jtable.
Originally posted by Philippe Maquet
Bing, not only I disagree with the tone of your post above dated posted May 18, 2004 09:29 AM (please keep our JavaRanch "be-nice" rule in mind when posting), but with the false assertions it contains either. *Any* question is welcome on this forum as far as it relates to some aspect of the SCJD assignment.
Originally posted by Guvenc Gulce
-> Does SCJD have some expiration period like SCJP.
My SCJP will expire in 5 months. Does that mean I can
not take SCJD anymore and I have to take SCJP once more ?
Why expiration date ? Does the java language change
drasticly every two year ?
The Sun Certified Java Developer Exam with J2SE 5: paper version from Amazon, PDF from Apress, Online reference: Books 24x7 Personal blog
Originally posted by david hu:
1)In non-network mode, we were told " the database and GUI must run in the same VM and must perform no networking".
Does that means that in this mode, two separate programs each containg a main() method(one is database manager, another is GUI)must start and run in the same VM? If this is case, how do they communicate?
Originally posted by Nicholas Cheung:
YES.
Originally posted by Philippe Maquet:
The answer is NO. Any Java application has one and only *one* main method.
Originally posted by Andrew Monkhouse:
Any application can have as many main methods as you like (...)
The Sun Certified Java Developer Exam with J2SE 5: paper version from Amazon, PDF from Apress, Online reference: Books 24x7 Personal blog
With a little knowledge, a cast iron skillet is non-stick and lasts a lifetime. |