Transaction diamond?

Question

          We're having a problem in our app which I've been able to duplicate using a simple
          bank account example. In this example we're using BMP, Container managed tx's,
          and all methods are marked as required. All session beans are stateless.
          State prior to client call: Account A has a balance of $100.
          (1) Client makes a call to BankTellerService to deposit $50 into Account A:
          long depositAndGetBalance( accountId, amountToDeposit ).
          All of the following are in the transaction started by the call in (1).
          (2) BankTellerService calls:
          void BankTransactionService.deposit( amountToDeposit )
          3) BankTransactionService looks up AccountBean and increases it's balance by amountToDeposit
          4) BankTellerSevice calls BalanceService to get the balance of Account A:
          long BalanceService.getBalance( accountId )
          5) BalanceService looks up the AccountBean for account A and returns it
          6) BankTellerService returns the balance to the client
          The balance returned is $100, which is identical to the initial state and does
          not reflect the deposit of $50.
          It appears that two seperate instances of Account A are being loaded, with the
          first instance receiving the deposit, and then the second instance being loaded.
          ejbStore is called sequentially, which means the the first instance stores the
          correct balance of $150, and then is overwritten by the second instance with a
          balance of $100.
          When we change the deployment descriptor to say <delay-updates-until-end-of-tx>false</delay...>,
          our problems are solved.
          Current answers from BEA support have said that this is by design and the default
          setting of delay=false causes this problem but is default for performance reasons.
          I just can't accept that because that would seem to violate sectino 17.7 of the
          spec, which states that the container is responsible for detecting this diamond
          and resolving the problem.
          Any ideas?
          Thanks,
          Matt
          

Answer 1

          Rob,
          You're the man. After testing it, I did fint that our PK class .equals method
          didn't work. If you'll look at the code I sent you,it was finally testing: this.id.equals(obj)
          instead of this.id.equals( ((BasePK)pk).id ).
          Thanks very much for the help.
          Matt Clark
          Rob Woollen <[email protected]> wrote:
          >
          >
          >The reason I asked about your primary key class is that your previous
          >message shows:
          >
          >> //Client calls depositAndGetNewBalance on remote interface
          >> //Container starts transaction
          >> // Container calls depositAndGetNewBalance on bean
          >> //enter BankTransactionService.deposit
          >> findByPrimaryKey: Hashcode: 721349
          >> ejbLoad: Balance 100 Hashcode 721349
          >> getAccountVO: Balance 100 Hashcode 721349
          >> setAccountVO: Balance 150 Hashcode 721349
          >> //exit BankTransactionService.deposit
          >>
          >> //enter BalanceService.getBalance
          >> findByPrimaryKey: Hashcode 2748333
          >> ejbLoad: Balance 100 Hashcode 2748333
          >>
          >This is where I'm concerned. Assuming that the deposit call and the
          >getBalance call both call the entity
          >bean with the same pk in the same tx, then there should only be one
          >instance used. However, here we see 2
          >instances.
          >
          >My guess is still that your pk hashCode and equals are off. (The container
          >uses them to determine whether
          >there is already an instance for this pk in use.)
          >
          >I would suggest that you add some debug messages to your hashCode and
          >equals methods. In particular, check
          >that when a.equals(b), a.hashCode() == b.hashCode(). Also make sure
          >that you're equals() method is not
          >returning false unexpectedly.
          >
          >If you're still having problems, post again, and we'll go from there.
          >
          >-- Rob
          >
          >> //exit BankTellerService.getBalance
          >> //exit depositAndGetNewBalance on bean
          >>
          >>
          >> ejbStore: Balance 150 Hashcode 721349
          >> ejbStore: Balance 100 Hashcode 2748333
          >> //Transaction done
          >> //Client deposit done
          >>
          >> //Client removes account
          >> findByPrimaryKey: Hashcode 5932239
          >> ejbLoad: Balance 100 Hashcode 5932239
          >> ejbRemove: Balance 100 Hashcode 5932239
          >> //Client done
          >>
          >Matt Clark wrote:
          >
          >> Rob,
          >>
          >> After thinking about why you asked to see the pk methods, I went and
          >looked at
          >> our implementation, and noticed that the hashcode method on OID is
          >faulty (missing
          >> some parentheses). However, afetr I fixed it we're still getting the
          >same problem.
          >> If I print out pk.hashCode(), I get all the same hashcode. If i print
          >out System.identityHashcode(
          >> pk ), I get different hashcodes, which I understand is because that
          >call calls
          >> Object.hashCode even if it has been overridden.
          >>
          >> Hope this helps,
          >>
          >> Matt
          >>
          >> "Matt Clark" <[email protected]> wrote:
          >> >
          >> >Sure.
          >> >
          >> >The BasePK class has a private attribute "id" of type OID, and here
          >are
          >> >the hashcode
          >> >and equals methods for BasePK:
          >> >
          >> >public int hashCode()
          >> >{
          >> > int code = 0;
          >> > if(id != null)
          >> > {
          >> > code = id.hashCode();
          >> > }
          >> > return code;
          >> >}
          >> >
          >> >public boolean equals(Object obj)
          >> >{
          >> > if( obj == null || !(obj instanceof BasePK) )
          >> > {
          >> > return false;
          >> > }
          >> > else if( (this.id == ((BasePK)obj).id) ||
          >> > (this.id != null && this.id.equals( obj ) ) )
          >> > {
          >> > return true;
          >> > }
          >> > else
          >> > {
          >> > return false;
          >> > }
          >> >}
          >> >
          >> >
          >> >The OID class has a private attribute byteArray of type byte[16].
          >It's
          >> >hashcode
          >> >and equals methods are:
          >> >
          >> >public int hashcode() {
          >> > return (int)( (getMostSignificantBytes() >> 32) & 0xFFFF +
          >> > (getMostSignificantBytes() ) & 0xFFFF +
          >> > (getLeastSignificantBytes() >> 32 ) & 0xFFFF +
          >> > (getLeastSignificantBytes() ) & 0xFFFF);
          >> >}
          >> >
          >> >public long getMoSignificantBytes() {
          >> > long mb;
          >> > mb=(((long)byteArray[15])&0xFF)<<56 |
          >> > (((long)byteArray[14])&0xFF)<<48 |
          >> > (((long)byteArray[13])&0xFF)<<40 |
          >> > (((long)byteArray[12])&0xFF)<<32 |
          >> > (((long)byteArray[11])&0xFF)<<24 |
          >> > (((long)byteArray[10])&0xFF)<<16 |
          >> > (((long)byteArray[9])&0xFF)<< 8 |
          >> > (((long)byteArray[8])&0xFF);
          >> > return mb;
          >> >}
          >> >
          >> >public long getLeastSignificantBytes() {
          >> > long lsb;
          >> > lsb=(((long)byteArray[7])&0xFF)<<56 |
          >> > (((long)byteArray[6])&0xFF)<<48 |
          >> > (((long)byteArray[5])&0xFF)<<40 |
          >> > (((long)byteArray[4])&0xFF)<<32 |
          >> > (((long)byteArray[3])&0xFF)<<24 |
          >> > (((long)byteArray[2])&0xFF)<<16 |
          >> > (((long)byteArray[1])&0xFF)<< 8 |
          >> > (((long)byteArray[0])&0xFF);
          >> > return lsb;
          >> >}
          >> >
          >> >public boolean equals( Object obj ) {
          >> > boolean equality = false;
          >> > if( obj == this )
          >> > {
          >> > equality = true;
          >> > }
          >> > else if( obj != null && obj instanceof OID )
          >> > {
          >> > OID other = (OID) obj;
          >> > equality = ( (other.getLeastSignificantBytes() ==
          >> > getLeastSignificantBytes() ) &&
          >> > (other.getMostSignificantBytes() ==
          >> > getMostSignificantBytes() ) );
          >> > }
          >> > return equality;
          >> >}
          >> >
          >> >
          >> >Rob Woollen <[email protected]> wrote:
          >> >>
          >> >>
          >> >>Can you show me the equals and hashCode implementations for your
          >pk
          >> >class?
          >> >>
          >> >>-- Rob
          >> >>
          >> >>Matt Clark wrote:
          >> >>
          >> >>> Rob,
          >> >>>
          >> >>> My BasePK implements Serializable, and contains one public member
          >> >variable
          >> >>of
          >> >>> type OID, which is a guid (or close to it anyway :) ) byte string.
          >> >>>
          >> >>> When I put in debugs to print out the balance and the System.identity(hashcode)
          >> >>> inside the callbacks, here is the sequence I see: (I've left out
          >the
          >> >>primary key
          >> >>> because it is somewhat long, but I've verified that it is the same
          >> >>for all calls
          >> >>> represented here )
          >> >>>
          >> >>> //Client creates account
          >> >>> ejbCreate: Balance 100 Hashcode 3452225
          >> >>> getAccountVO: Balance 100 Hashcode 3452225
          >> >>> ejbStore: Balance 100 Hashcode 3452225
          >> >>>
          >> >>> //Client calls depositAndGetNewBalance on remote interface
          >> >>> //Container starts transaction
          >> >>> // Container calls depositAndGetNewBalance on bean
          >> >>> //enter BankTransactionService.deposit
          >> >>> findByPrimaryKey: Hashcode: 721349
          >> >>> ejbLoad: Balance 100 Hashcode 721349
          >> >>> getAccountVO: Balance 100 Hashcode 721349
          >> >>> setAccountVO: Balance 150 Hashcode 721349
          >> >>> //exit BankTransactionService.deposit
          >> >>>
          >> >>> //enter BalanceService.getBalance
          >> >>> findByPrimaryKey: Hashcode 2748333
          >> >>> ejbLoad: Balance 100 Hashcode 2748333
          >> >>> //exit BankTellerService.getBalance
          >> >>> //exit depositAndGetNewBalance on bean
          >> >>>
          >> >>> ejbStore: Balance 150 Hashcode 721349
          >> >>> ejbStore: Balance 100 Hashcode 2748333
          >> >>> //Transaction done
          >> >>> //Client deposit done
          >> >>>
          >> >>> //Client removes account
          >> >>> findByPrimaryKey: Hashcode 5932239
          >> >>> ejbLoad: Balance 100 Hashcode 5932239
          >> >>> ejbRemove: Balance 100 Hashcode 5932239
          >> >>> //Client done
          >> >>>
          >> >>> Let me know if you need any mroe detail...
          >> >>>
          >> >>> Matt
          >> >>> Rob Woollen <[email protected]> wrote:
          >> >>> >
          >> >>> >
          >> >>> >You're going to have to provide some more info for me to know
          >what's
          >> >>> >going on.
          >> >>> >
          >> >>> >I'd suggest that you add print messages like this to the callbacks:
          >> >>> >
          >> >>> >System.out.println("ejbLoad called in id: "+System.identityHashCode(this)+
          >> >>> > " with pk: "+ctx.getPrimaryKey());
          >> >>> >
          >> >>> >Put a message like this in ejbLoad, ejbStore, ejbFindByPrimaryKey
          >> >>(also
          >> >>> >any other finders that
          >> >>> >you're using), and the business methods.
          >> >>> >
          >> >>> >Show me the output, and I'll have a look.
          >> >>> >
          >> >>> >Also, what class are you using for the primary key of the Account
          >> >>bean?
          >> >>> >
          >> >>> >-- Rob
          >> >>> >
          >> >>> >Matt Clark wrote:
          >> >>> >
          >> >>> >> Correction to step 5 in the email. BalanceService returns the
          >> >balance
          >> >>> >of AccountA,
          >> >>> >> not the AccountBean itself...
          >> >>> >>
          >> >>> >> "Matt Clark" <[email protected]> wrote:
          >> >>> >> >
          >> >>> >> >We're having a problem in our app which I've been able to duplicate
          >> >>> >using
          >> >>> >> >a simple
          >> >>> >> >bank account example. In this example we're using BMP, Container
          >> >>> >managed
          >> >>> >> >tx's,
          >> >>> >> >and all methods are marked as required. All session beans are
          >> >stateless.
          >> >>> >> >
          >> >>> >> >State prior to client call: Account A has a balance of $100.
          >> >>> >> >
          >> >>> >> >(1) Client makes a call to BankTellerService to deposit $50
          >into
          >> >>Account
          >> >>> >> >A:
          >> >>> >> > long depositAndGetBalance( accountId, amountToDeposit
          >).
          >> >>> >> >
          >> >>> >> >All of the following are in the transaction started by the
          >call
          >> >>in
          >> >>> >(1).
          >> >>> >> >
          >> >>> >> >(2) BankTellerService calls:
          >> >>> >> > void BankTransactionService.deposit( amountToDeposit )
          >> >>> >> >
          >> >>> >> >3) BankTransactionService looks up AccountBean and increases
          >it's
          >> >>> >balance
          >> >>> >> >by amountToDeposit
          >> >>> >> >
          >> >>> >> >4) BankTellerSevice calls BalanceService to get the balance
          >of
          >> >>Account
          >> >>> >> >A:
          >> >>> >> > long BalanceService.getBalance( accountId )
          >> >>> >> >
          >> >>> >> >5) BalanceService looks up the AccountBean for account A and
          >returns
          >> >>> >> >it
          >> >>> >> >
          >> >>> >> >6) BankTellerService returns the balance to the client
          >> >>> >> >
          >> >>> >> >The balance returned is $100, which is identical to the initial
          >> >>state
          >> >>> >> >and does
          >> >>> >> >not reflect the deposit of $50.
          >> >>> >> >
          >> >>> >> >It appears that two seperate instances of Account A are being
          >> >loaded,
          >> >>> >> >with the
          >> >>> >> >first instance receiving the deposit, and then the second instance
          >> >>> >being
          >> >>> >> >loaded.
          >> >>> >> > ejbStore is called sequentially, which means the the first
          >instance
          >> >>> >> >stores the
          >> >>> >> >correct balance of $150, and then is overwritten by the second
          >> >>instance
          >> >>> >> >with a
          >> >>> >> >balance of $100.
          >> >>> >> >
          >> >>> >> >When we change the deployment descriptor to say <delay-updates-until-end-of-tx>false</delay...>,
          >> >>> >> >our problems are solved.
          >> >>> >> >
          >> >>> >> >Current answers from BEA support have said that this is by
          >design
          >> >>> >and
          >> >>> >> >the default
          >> >>> >> >setting of delay=false causes this problem but is default for
          >> >performance
          >> >>> >> >reasons.
          >> >>> >> > I just can't accept that because that would seem to violate
          >sectino
          >> >>> >> >17.7 of the
          >> >>> >> >spec, which states that the container is responsible for detecting
          >> >>> >this
          >> >>> >> >diamond
          >> >>> >> >and resolving the problem.
          >> >>> >> >
          >> >>> >> >Any ideas?
          >> >>> >> >
          >> >>> >> >Thanks,
          >> >>> >> >Matt
          >> >>> >
          >> >>
          >> >>--
          >> >>
          >> >>----------------------------------------------------------------------
          >> >>
          >> >>AVAILABLE NOW!: Building J2EE Applications & BEA WebLogic Server
          >> >>
          >> >>by Michael Girdley, Rob Woollen, and Sandra Emerson
          >> >>
          >> >>http://learnWebLogic.com
          >> >>
          >> >>
          >> >>
          >> >>
          >> >><!doctype html public "-//w3c//dtd html 4.0 transitional//en">
          >> >><html>
          >> >>Can you show me the equals and hashCode implementations for your
          >pk
          >> >class?
          >> >><p>-- Rob
          >> >><p>Matt Clark wrote:
          >> >><blockquote TYPE=CITE>Rob,
          >> >><p>My BasePK implements Serializable, and contains one public member
          >> >>variable
          >> >>of
          >> >><br>type OID, which is a guid (or close to it anyway :) ) byte string.
          >> >><p>When I put in debugs to print out the balance and the System.identity(hashcode)
          >> >><br>inside the callbacks, here is the sequence I see: (I've left
          >out
          >> >>the
          >> >>primary key
          >> >><br>because it is somewhat long, but I've verified that it is the
          >same
          >> >>for all calls
          >> >><br>represented here )
          >> >><p>//Client creates account
          >> >><br>ejbCreate: Balance 100 Hashcode 3452225
          >> >><br>getAccountVO: Balance 100 Hashcode 3452225
          >> >><br>ejbStore: Balance 100 Hashcode 3452225
          >> >><p>//Client calls depositAndGetNewBalance on remote interface
          >> >><br> //Container starts transaction
          >> >><br> // Container calls depositAndGetNewBalance on
          >> >>bean
          >> >><br> //enter BankTransactionService.deposit
          >> >><br> findByPrimaryKey: Hashcode:
          >> >>721349
          >> >><br> ejbLoad: Balance 100 Hashcode
          >> >>721349
          >> >><br> getAccountVO: Balance
          >> >>100
          >> >>Hashcode 721349
          >> >><br> setAccountVO: Balance
          >> >>150
          >> >>Hashcode 721349
          >> >><br> //exit BankTransactionService.deposit
          >> >><p> //enter BalanceService.getBalance
          >> >><br> findByPrimaryKey: Hashcode
          >> >>2748333
          >> >><br> ejbLoad: Balance
          >> >>100
          >> >>Hashcode 2748333
          >> >><br> //exit BankTellerService.getBalance
          >> >><br> //exit depositAndGetNewBalance on bean
          >> >><p> ejbStore: Balance 150 Hashcode 721349
          >> >><br> ejbStore: Balance 100 Hashcode 2748333
          >> >><br> //Transaction done
          >> >><br>//Client deposit done
          >> >><p>//Client removes account
          >> >><br>findByPrimaryKey: Hashcode 5932239
          >> >><br>ejbLoad: Balance 100 Hashcode 5932239
          >> >><br>ejbRemove: Balance 100 Hashcode 5932239
          >> >><br>//Client done
          >> >><p>Let me know if you need any mroe detail...
          >> >><p>Matt
          >> >><br>Rob Woollen <[email protected]> wrote:
          >> >><br>>
          >> >><br>>
          >> >><br>>You're going to have to provide some more info for me to know
          >what's
          >> >><br>>going on.
          >> >><br>>
          >> >><br>>I'd suggest that you add print messages like this to the callbacks:
          >> >><br>>
          >> >><br>>System.out.println("ejbLoad called in id: "+System.identityHashCode(this)+
          >> >><br>>
          >> >>" with pk: "+ctx.getPrimaryKey());
          >> >><br>>
          >> >><br>>Put a message like this in ejbLoad, ejbStore, ejbFindByPrimaryKey
          >> >>(also
          >> >><br>>any other finders that
          >> >><br>>you're using), and the business methods.
          >> >><br>>
          >> >><br>>Show me the output, and I'll have a look.
          >> >><br>>
          >> >><br>>Also, what class are you using for the primary key of the Account
          >> >>bean?
          >> >><br>>
          >> >><br>>-- Rob
          >> >><br>>
          >> >><br>>Matt Clark wrote:
          >> >><br>>
          >> >><br>>> Correction to step 5 in the email. BalanceService returns
          >> >>the balance
          >> >><br>>of AccountA,
          >> >><br>>> not the AccountBean itself...
          >> >><br>>>
          >> >><br>>> "Matt Clark" <[email protected]> wrote:
          >> >><br>>> >
          >> >><br>>> >We're having a problem in our app which I've been able to
          >duplicate
          >> >><br>>using
          >> >><br>>> >a simple
          >> >><br>>> >bank account example. In this example we're using BMP,
          >> >>Container
          >> >><br>>managed
          >> >><br>>> >tx's,
          >> >><br>>> >and all methods are marked as required. All session beans
          >are
          >> >>stateless.
          >> >><br>>> >
          >> >><br>>> >State prior to client call: Account A has a balance of $100.
          >> >><br>>> >
          >> >><br>>> >(1) Client makes a call to BankTellerService to deposit $50
          >> >into
          >> >>Account
          >> >><br>>> >A:
          >> >><br>>> > long depositAndGetBalance( accountId,
          >> >>amountToDeposit ).
          >> >><br>>> >
          >> >><br>>> >All of the following are in the transaction started by the
          >call
          >> >>in
          >> >><br>>(1).
          >> >><br>>> >
          >> >><br>>> >(2) BankTellerService calls:
          >> >><br>>> > void BankTransactionService.deposit(
          >> >>amountToDeposit
          >> >>)
          >> >><br>>> >
          >> >><br>>> >3) BankTransactionService looks up AccountBean and increases
          >> >>it's
          >> >><br>>balance
          >> >><br>>> >by amountToDeposit
          >> >><br>>> >
          >> >><br>>> >4) BankTellerSevice calls BalanceService to get the balance
          >> >of
          >> >>Account
          >> >><br>>> >A:
          >> >><br>>> > long BalanceService.getBalance( accountId
          >> >>)
          >> >><br>>> >
          >> >><br>>> >5) BalanceService looks up the AccountBean for account A
          >and
          >> >>returns
          >> >><br>>> >it
          >> >><br>>> >
          >> >><br>>> >6) BankTellerService returns the balance to the client
          >> >><br>>> >
          >> >><br>>> >The balance returned is $100, which is identical to the initial
          >> >>state
          >> >><br>>> >and does
          >> >><br>>> >not reflect the deposit of $50.
          >> >><br>>> >
          >> >><br>>> >It appears that two seperate instances of Account A are being
          >> >>loaded,
          >> >><br>>> >with the
          >> >><br>>> >first instance receiving the deposit, and then the second
          >instance
          >> >><br>>being
          >> >><br>>> >loaded.
          >> >><br>>> > ejbStore is called sequentially, which means the the first
          >> >instance
          >> >><br>>> >stores the
          >> >><br>>> >correct balance of $150, and then is overwritten by the second
          >> >>instance
          >> >><br>>> >with a
          >> >><br>>> >balance of $100.
          >> >><br>>> >
          >> >><br>>> >When we change the deployment descriptor to say <delay-updates-until-end-of-tx>false</delay...>,
          >> >><br>>> >our problems are solved.
          >> >><br>>> >
          >> >><br>>> >Current answers from BEA support have said that this is by
          >design
          >> >><br>>and
          >> >><br>>> >the default
          >> >><br>>> >setting of delay=false causes this problem but is default
          >for
          >> >>performance
          >> >><br>>> >reasons.
          >> >><br>>> > I just can't accept that because that would seem to violate
          >> >>sectino
          >> >><br>>> >17.7 of the
          >> >><br>>> >spec, which states that the container is responsible for
          >detecting
          >> >><br>>this
          >> >><br>>> >diamond
          >> >><br>>> >and resolving the problem.
          >> >><br>>> >
          >> >><br>>> >Any ideas?
          >> >><br>>> >
          >> >><br>>> >Thanks,
          >> >><br>>> >Matt
          >> >><br>></blockquote>
          >> >>
          >> >><pre>--
          >> >>
          >> >>----------------------------------------------------------------------
          >> >>
          >> >>AVAILABLE NOW!: Building J2EE Applications & BEA WebLogic Server
          >> >>
          >> >>by Michael Girdley, Rob Woollen, and Sandra Emerson
          >> >>
          >> >>http://learnWebLogic.com</pre>
          >> >> </html>
          >> >>
          >> >>
          >> >
          >
          >
          ><!doctype html public "-//w3c//dtd html 4.0 transitional//en">
          ><html>
          >The reason I asked about your primary key class is that your previous
          >message
          >shows:
          ><blockquote TYPE=CITE>
          ><pre>//Client calls depositAndGetNewBalance on remote interface
          >  //Container starts transaction
          >    // Container calls depositAndGetNewBalance on bean
          >      //enter BankTransactionService.deposit
          >        findByPrimaryKey: Hashcode:
          >721349
          >        ejbLoad: Balance 100 Hashcode
          >721349
          >        getAccountVO: Balance 100
          >Hashcode 721349
          >        setAccountVO: Balance 150
          >Hashcode 721349
          >      //exit BankTransactionService.deposit
          >
          >      //enter BalanceService.getBalance
          >        findByPrimaryKey: Hashcode
          >2748333
          >        ejbLoad:  Balance 100
          >Hashcode 2748333</pre>
          ></blockquote>
          >This is where I'm concerned.  Assuming that the deposit call and
          >the
          >getBalance call both call the entity bean with the same pk in the same
          >tx,  then there should only be one instance used.  However,
          >here
          >we see 2 instances.
          ><p>My guess is still that your pk hashCode and equals are off. 
          >(The
          >container uses them to determine whether there is already an instance
          >for
          >this pk in use.)
          ><p>I would suggest that you add some debug messages to your hashCode
          >and
          >equals methods.  In particular, check that when a.equals(b), a.hashCode()
          >== b.hashCode().  Also make sure that you're equals() method is
          >not
          >returning false unexpectedly.
          ><p>If you're still having problems, post again, and we'll go from there.
          ><p>-- Rob
          ><blockquote TYPE=CITE>
          ><pre>
          >      //exit BankTellerService.getBalance
          >    //exit depositAndGetNewBalance on bean
          >
          >
          >    ejbStore: Balance 150 Hashcode 721349
          >    ejbStore: Balance 100 Hashcode 2748333
          >  //Transaction done
          >//Client deposit done
          >
          >//Client removes account
          >findByPrimaryKey: Hashcode 5932239
          >ejbLoad: Balance 100 Hashcode 5932239
          >ejbRemove: Balance 100 Hashcode 5932239
          >//Client done</pre>
          ></blockquote>
          >
          ><p>Matt Clark wrote:
          ><blockquote TYPE=CITE>Rob,
          ><p>After thinking about why you asked to see the pk methods, I went and
          >looked at
          ><br>our implementation, and noticed that the hashcode method on OID is
          >faulty (missing
          ><br>some parentheses). However, afetr I fixed it we're still getting
          >the
          >same problem.
          ><br> If I print out pk.hashCode(), I get all the same hashcode. 
          >If i print out System.identityHashcode(
          ><br>pk ), I get different hashcodes, which I understand is because that
          >call calls
          ><br>Object.hashCode even if it has been overridden.
          ><p>Hope this helps,
          ><p>Matt
          ><p>"Matt Clark" <[email protected]> wrote:
          ><br>>
          ><br>>Sure.
          ><br>>
          ><br>>The BasePK class has a private attribute "id" of type OID, and here
          >are
          ><br>>the hashcode
          ><br>>and equals methods for BasePK:
          ><br>>
          ><br>>public int hashCode()
          ><br>>{
          ><br>>    int code = 0;
          ><br>>    if(id != null)
          ><br>>    {
          ><br>>        code = id.hashCode();
          ><br>>    }
          ><br>>    return code;
          ><br>>}
          ><br>>
          ><br>>public boolean equals(Object obj)
          ><br>>{
          ><br>>    if( obj == null || !(obj instanceof BasePK) )
          ><br>>    {
          ><br>>        return false;
          ><br>>    }
          ><br>>    else if( (this.id == ((BasePK)obj).id) ||
          ><br>>            
          >(this.id != null && this.id.equals( obj ) ) )
          ><br>>    {
          ><br>>        return true;
          ><br>>    }
          ><br>>    else
          ><br>>    {
          ><br>>        return false;
          ><br>>    }
          ><br>>}
          ><br>>
          ><br>>
          ><br>>The OID class has a private attribute byteArray of type byte[16].
          >It's
          ><br>>hashcode
          ><br>>and equals methods are:
          ><br>>
          ><br>>public int hashcode() {
          ><br>>    return (int)( (getMostSignificantBytes() >> 32)
          >& 0xFFFF +
          ><br>>                 
          >(getMostSignificantBytes()      ) & 0xFFFF
          >+
          ><br>>                 
          >(getLeastSignificantBytes() >> 32 ) & 0xFFFF +
          ><br>>                 
          >(getLeastSignificantBytes()       ) &
          >0xFFFF);
          ><br>>}
          ><br>>
          ><br>>public long getMoSignificantBytes() {
          ><br>>    long mb;
          ><br>>    mb=(((long)byteArray[15])&0xFF)<<56
          >|
          ><br>>        (((long)byteArray[14])&0xFF)<<48
          >|
          ><br>>        (((long)byteArray[13])&0xFF)<<40
          >|
          ><br>>        (((long)byteArray[12])&0xFF)<<32
          >|
          ><br>>        (((long)byteArray[11])&0xFF)<<24
          >|
          ><br>>        (((long)byteArray[10])&0xFF)<<16
          >|
          ><br>>        (((long)byteArray[9])&0xFF)<<
          >8 |
          ><br>>        (((long)byteArray[8])&0xFF);
          ><br>>    return mb;
          ><br>>}
          ><br>>
          ><br>>public long getLeastSignificantBytes() {
          ><br>>    long lsb;
          ><br>>    lsb=(((long)byteArray[7])&0xFF)<<56
          >|
          ><br>>        (((long)byteArray[6])&0xFF)<<48
          >|
          ><br>>        (((long)byteArray[5])&0xFF)<<40
          >|
          ><br>>        (((long)byteArray[4])&0xFF)<<32
          >|
          ><br>>        (((long)byteArray[3])&0xFF)<<24
          >|
          ><br>>        (((long)byteArray[2])&0xFF)<<16
          >|
          ><br>>        (((long)byteArray[1])&0xFF)<<
          >8 |
          ><br>>        (((long)byteArray[0])&0xFF);
          ><br>>    return lsb;
          ><br>>}
          ><br>>
          ><br>>public boolean equals( Object obj ) {
          ><br>>    boolean equality = false;
          ><br>>    if( obj == this )
          ><br>>    {
          ><br>>       equality = true;
          ><br>>    }
          ><br>>    else if( obj != null && obj instanceof
          >OID )
          ><br>>    {
          ><br>>        OID other = (OID) obj;
          ><br>>        equality = ( (other.getLeastSignificantBytes()
          >==
          ><br>>                       
          >getLeastSignificantBytes() ) &&
          ><br>>                    
          >(other.getMostSignificantBytes() ==
          ><br>>                       
          >getMostSignificantBytes() ) );
          ><br>>    }
          ><br>>    return equality;
          ><br>>}
          ><br>>
          ><br>>
          ><br>>Rob Woollen <[email protected]> wrote:
          ><br>>>
          ><br>>>
          ><br>>>Can you show me the equals and hashCode implementations for your
          >pk
          ><br>>class?
          ><br>>>
          ><br>>>-- Rob
          ><br>>>
          ><br>>>Matt Clark wrote:
          ><br>>>
          ><br>>>> Rob,
          ><br>>>>
          ><br>>>> My BasePK implements Serializable, and contains one public member
          ><br>>variable
          ><br>>>of
          ><br>>>> type OID, which is a guid (or close to it anyway :) ) byte string.
          ><br>>>>
          ><br>>>> When I put in debugs to print out the balance and the System.identity(hashcode)
          ><br>>>> inside the callbacks, here is the sequence I see: (I've left
          >out
          >the
          ><br>>>primary key
          ><br>>>> because it is somewhat long, but I've verified that it is the
          >same
          ><br>>>for all calls
          ><br>>>> represented here )
          ><br>>>>
          ><br>>>> //Client creates account
          ><br>>>> ejbCreate: Balance 100 Hashcode 3452225
          ><br>>>> getAccountVO: Balance 100 Hashcode 3452225
          ><br>>>> ejbStore: Balance 100 Hashcode 3452225
          ><br>>>>
          ><br>>>> //Client calls depositAndGetNewBalance on remote interface
          ><br>>>>   //Container starts transaction
          ><br>>>>     // Container calls depositAndGetNewBalance
          >on bean
          ><br>>>>       //enter BankTransactionService.deposit
          ><br>>>>         findByPrimaryKey:
          >Hashcode: 721349
          ><br>>>>         ejbLoad: Balance
          >100 Hashcode 721349
          ><br>>>>         getAccountVO:
          >Balance
          >100 Hashcode 721349
          ><br>>>>         setAccountVO:
          >Balance
          >150 Hashcode 721349
          ><br>>>>       //exit BankTransactionService.deposit
          ><br>>>>
          ><br>>>>       //enter BalanceService.getBalance
          ><br>>>>         findByPrimaryKey:
          >Hashcode 2748333
          ><br>>>>         ejbLoad: 
          >Balance 100 Hashcode 2748333
          ><br>>>>       //exit BankTellerService.getBalance
          ><br>>>>     //exit depositAndGetNewBalance on bean
          ><br>>>>
          ><br>>>>     ejbStore: Balance 150 Hashcode 721349
          ><br>>>>     ejbStore: Balance 100 Hashcode 2748333
          ><br>>>>   //Transaction done
          ><br>>>> //Client deposit done
          ><br>>>>
          ><br>>>> //Client removes account
          ><br>>>> findByPrimaryKey: Hashcode 5932239
          ><br>>>> ejbLoad: Balance 100 Hashcode 5932239
          ><br>>>> ejbRemove: Balance 100 Hashcode 5932239
          ><br>>>> //Client done
          ><br>>>>
          ><br>>>> Let me know if you need any mroe detail...
          ><br>>>>
          ><br>>>> Matt
          ><br>>>> Rob Woollen <[email protected]> wrote:
          ><br>>>> >
          ><br>>>> >
          ><br>>>> >You're going to have to provide some more info for me to know
          >what's
          ><br>>>> >going on.
          ><br>>>> >
          ><br>>>> >I'd suggest that you add print messages like this to the callbacks:
          ><br>>>> >
          ><br>>>> >System.out.println("ejbLoad called in id: "+System.identityHashCode(this)+
          ><br>>>> >                                     
          >" with pk: "+ctx.getPrimaryKey());
          ><br>>>> >
          ><br>>>> >Put a message like this in ejbLoad, ejbStore, ejbFindByPrimaryKey
          ><br>>>(also
          ><br>>>> >any other finders that
          ><br>>>> >you're using), and the business methods.
          ><br>>>> >
          ><br>>>> >Show me the output, and I'll have a look.
          ><br>>>> >
          ><br>>>> >Also, what class are you using for the primary key of the Account
          ><br>>>bean?
          ><br>>>> >
          ><br>>>> >-- Rob
          ><br>>>> >
          ><br>>>> >Matt Clark wrote:
          ><br>>>> >
          ><br>>>> >> Correction to step 5 in the email.  BalanceService returns
          >the
          ><br>>balance
          ><br>>>> >of AccountA,
          ><br>>>> >> not the AccountBean itself...
          ><br>>>> >>
          ><br>>>> >> "Matt Clark" <[email protected]> wrote:
          ><br>>>> >> >
          ><br>>>> >> >We're having a problem in our app which I've been able to
          >duplicate
          ><br>>>> >using
          ><br>>>> >> >a simple
          ><br>>>> >> >bank account example.  In this example we're using BMP,
          >Container
          ><br>>>> >managed
          ><br>>>> >> >tx's,
          ><br>>>> >> >and all methods are marked as required. All session beans
          >are
          ><br>>stateless.
          ><br>>>> >> >
          ><br>>>> >> >State prior to client call: Account A has a balance of $100.
          ><br>>>> >> >
          ><br>>>> >> >(1) Client makes a call to BankTellerService to deposit $50
          >into
          ><br>>>Account
          ><br>>>> >> >A:
          ><br>>>> >> >    long  depositAndGetBalance( accountId,
          >amountToDeposit ).
          ><br>>>> >> >
          ><br>>>> >> >All of the following are in the transaction started by the
          >call
          ><br>>>in
          ><br>>>> >(1).
          ><br>>>> >> >
          ><br>>>> >> >(2) BankTellerService calls:
          ><br>>>> >> >     void BankTransactionService.deposit(
          >amountToDeposit )
          ><br>>>> >> >
          ><br>>>> >> >3) BankTransactionService looks up AccountBean and increases
          >it's
          ><br>>>> >balance
          ><br>>>> >> >by amountToDeposit
          ><br>>>> >> >
          ><br>>>> >> >4) BankTellerSevice calls BalanceService to get the balance
          >of
          ><br>>>Account
          ><br>>>> >> >A:
          ><br>>>> >> >     long BalanceService.getBalance(
          >accountId
          >)
          ><br>>>> >> >
          ><br>>>> >> >5) BalanceService looks up the AccountBean for account A
          >and
          >returns
          ><br>>>> >> >it
          ><br>>>> >> >
          ><br>>>> >> >6) BankTellerService returns the balance to the client
          ><br>>>> >> >
          ><br>>>> >> >The balance returned is $100, which is identical to the initial
          ><br>>>state
          ><br>>>> >> >and does
          ><br>>