Harish Yerneni

Hi

This link had a similar example but they used net beans
http://wiki.netbeans.org/CreatingEJB3UsingNetbeansAndGlassfish

Hope this helps!

Harish

Congrats, Mohamed. Hard work paid off. I am also trying to wrap up my assignment and submit.

Thank you, Lee.

Harish

Congrats, great score!!!

Harish

Hello Ranchers:

I am trying to run concurrency test on delete method. My pseudo code is

cookie = 0; try { cookie = lockRecord(recNo); deleteRecord(recNo, Cookie); } catch (RecordNotFoundException){ } finally { try { unlock(recNo, cookie); } catch (SecurityException) { } }

Consider this scenario:
100 = lockRecord(5)
deleteRecord(5, 100)
unlock(5, 100)

lockRecord(5) will throw RNFE
unlock(5, 0) will throw Security Exception when in theory I was expecting RNFE.
unlock() method had only SecurityException and didnt have RecordNotFoundException in the signature in my
assignment. How is everyone handling this?

Thanks,

Harish

Start Reading Monkhouse book. It has all the background needed. Do more research on a topic by topic basis as you read the book.

Harish

Congrats, Rohan. You did it at a Rocket speed!!!

Harish

Congrats, Musab.

Harish

Congrats, Alex. What next?

Harish

Congrats, Andre

Harish

Congrats, Perfect score!!!

Harish

Never give any of your original documents to anybody. You can give them photocopies if they want. I have heard about people taking passports also. This is against law.

Contract of 18 months without sponsoring h1-b and giving 60 percent later on doesnt sound good to me at all.

AVOID that company.

Harish

Well done. Nicholas. What next?

congrats, Xabier

Harish

Hi all:

Here is the spec I got
// Deletes a record, making the record number and associated disk // storage available for reuse. // Throws SecurityException if the record is locked with a cookie // other than lockCookie. public void deleteRecord(long recNo, long lockCookie) throws RecordNotFoundException, SecurityException


I have checked for RNFE if the record is not existing in FileManager hashmap or already marked as deleted. I have thrown security exception, when cookie is not matching with the existing cookie in the hashmap or if recno doesnt exist in the lockManager hashmap itself(question: am I OK here).

I have seen in many posts they are recommending
lockRecord() - can somebody explain me why we should use lockRecord() here. I am thinking we are deleting an already locked record. If we use lockRecord(), dont we get a new cookie value here.
deleteRecord() - fine
unlock() - fine

Here is what I have coded in my Data.class
public void deleteRecord(long recNo, long lockCookie) throws RecordNotFoundException, SecurityException, DataAccessException { //to check if the record exists at all in recordNumbers //and also if exists not already marked for deleted. if (fileManager.recordExists(recNo)) { //Check if the (recNo, cookie) exists in lockedRecords //returns false even if recNo doesnt exist in the hash map OK? // *DOCUMENT* //Now the thread/client should already have the lock. //No need to lock. if (lockManager.isLocked(recNo, lockCookie)) { fileManager.deleteRecord(recNo); lockManager.unlock(recNo, lockCookie); } else { throw new SecurityException(); } } else { throw new RecordNotFoundException("RecordNotFoundException: deleteRecord()"); } }

thanks,

Harish

question: Why should we lock() first, if the record is already