hi! will do :)
back when i started with castor, about a month ago i guess, i skipped that part. Now that i am able to work properly with castor, its about time i take a look a that. thanks again :) regards, noc2 Ralf Joachim-2 wrote: > > Hi Noc2, > > take a look at: http://castor.codehaus.org/key-generator.html about the > options you have with keygenerators. > > Regards > Ralf > > > Noc2 schrieb: >> hello Ralf! >> >> Thanks for you reply! I understand the problem now. Thanks for the >> explanation. >> >> While i was busy with the problem i noticed something else as well. I >> mentioned something about mysql doing an auto-incrementation of the ID in >> the Performance table. >> >> With the knowledge of your reply, i changed the code yesterday. I made a >> new >> field in the database called "Date" of the type date, and the start and >> stop >> have become bigint in the database. When i need to display time, the >> bigints >> are turned into longs, and the longs are then used in the Timeconstructor >> in >> java. >> >> Anyway, i decided to disable the auto-incrementation. I had to write >> something to generate keys then, and i needed to test it. But my testcode >> of >> performance, and the testdatabase hadnt been changed yet, so i there was >> no >> bigint or separate "date" field yet, and you know what? With the >> auto-increment disabled, the code did work. >> >> Are there perhaps any known bugs with the auto-increment? i performed a >> quick search, but on behalf of my job, i cant spend too much time on >> googling for problems that have been resolved already. >> >> Again, thank you very much for your reply, i learned something from it. >> >> regards, >> noc2 >> >> >> >> Ralf Joachim-2 wrote: >>> Hi Noc2, >>> >>> according to your description I can not see anything that you may be >>> doing wrong. But there is one problem that I faced myself sometime ago. >>> >>> Let's assume you set your start timestamp as follows: >>> >>> perf.setStart(new Date()); >>> >>> The start timestamp then holds a value that has millisecond resolution. >>> If you store this value to a database column that has only second >>> resolution the milliseconds will not be contained in the database. If >>> you try to update this object in another transaction Castor will load >>> the object from the database and compares it with the cached one. At >>> this time Castor recognizes that the start timestamp form the database >>> is not the same as the one of the object in cache because the >>> milliseconds are missing. This will lead to a ObjectModifiedException as >>> seen by you. >>> >>> Having said that this may also happen with other datatypes (e.g. if you >>> store a 30 char string into a database field with only 25 chars). >>> >>> Regards >>> Ralf >>> >>> >>> Noc2 schrieb: >>>> Hello everybody, >>>> >>>> I am back with a new problem, a real mindcracker for me. As usual, it >>>> is >>>> possible that this problem is as easy as cake, then i will feel stupid >>>> again, but as it is now (with my limited knowledge) i cant seem to find >>>> a >>>> solution. >>>> >>>> The situation is as following: >>>> >>>> check the next piece of mapping: >>>> >>>> <<<<<<<<<<<<<<<<<<<mapping>>>>>>>>>>>>>>>> >>>> >>>> <field name="start" type="date"> >>>> <sql name="start" type="timestamp" /> >>>> </field> >>>> >>>> <field name="stop" type="date"> >>>> <sql name="stop" type="timestamp" /> >>>> </field> >>>> >>>> <<<<<<<<<<<<<<<<<< end of mapping >>>>>>>>>>> >>>> >>>> As you can see, i am trying to "convert" java date obj into a timestamp >>>> object. >>>> This piece of mapping tries to map a Performance Object, the code >>>> following >>>> here: >>>> >>>> *********************** start of code ************************** >>>> >>>> public class Performance implements TimeStampable { >>>> >>>> private int performanceID; >>>> private int userID; >>>> private int activityID; >>>> private Date start; >>>> private Date stop; >>>> >>>> private long timestamp = 0; >>>> >>>> public long jdoGetTimeStamp(){ >>>> return timestamp; >>>> } >>>> >>>> public void jdoSetTimeStamp(long timestamp){ >>>> this.timestamp = timestamp; >>>> } >>>> >>>> >>>> public int getUserID() { >>>> return userID; >>>> } >>>> public void setUserID(int userID) { >>>> this.userID = userID; >>>> } >>>> public int getActivityID() { >>>> return activityID; >>>> } >>>> public void setActivityID(int activityID) { >>>> this.activityID = activityID; >>>> } >>>> public Date getStart() { >>>> return start; >>>> } >>>> public void setStart(Date start) { >>>> this.start = start; >>>> } >>>> public Date getStop() { >>>> return stop; >>>> } >>>> public void setStop(Date stop) { >>>> this.stop = stop; >>>> } >>>> public int getPerformanceID() { >>>> return performanceID; >>>> } >>>> public void setPerformanceID(int performanceID) { >>>> this.performanceID = performanceID; >>>> } >>>> } >>>> >>>> ************************** end of code *************************** >>>> >>>> As you all can see, not much about it. >>>> >>>> I recently solved the problems i had with caching and long >>>> transactions, >>>> everything worked perfectly, until i tried to create and update >>>> Performance >>>> objects in long transactions. >>>> >>>> The scenario is as following: i create a performance object to track >>>> the >>>> start of some activity. Due to database restrictions (mysql), it is >>>> impossible to have a timestamp entry that is null (this might have >>>> nothing >>>> to do with the problem but i think its better to just tell everything). >>>> >>>> Ofcourse i also need to know when the activity stops, so i perform an >>>> update >>>> on the Performance object when the activity stops, and i would then >>>> like >>>> to >>>> create a new Performance object for the next Activity. >>>> >>>> But on the update, i get the following Exception and errormessage: >>>> >>>> org.exolab.castor.jdo.ObjectModifiedException: Invalid object timestamp >>>> detected. >>>> >>>> Now, to me, this looks very strange. ObjectModifiedException is thrown >>>> when >>>> there is a concurrency problem, more accurate, when one transaction is >>>> modifying an entry used by another transaction. >>>> In my case, this is not really possible, because every single operation >>>> i >>>> perform on the database is a transaction that has been committed. To >>>> prove >>>> this, i ll give the code i use to update. >>>> >>>> ************** start of code ************* >>>> public void update(Object updatedObject) { >>>> try { >>>> db.begin(); >>>> >>>> db.update(updatedObject); >>>> >>>> logger.info("UPDATE COMPLETED"); >>>> >>>> db.commit(); >>>> >>>> } catch (PersistenceException e) { >>>> logger.fatal("PersistanceException : " + >>>> e.getMessage()); >>>> e.printStackTrace(); >>>> } >>>> } >>>> ********************* end of code ************** >>>> In the application, when i create the currentPerformanceObject, it has >>>> no >>>> ID. I let MySql create an auto increasing number for that. So i figured >>>> i >>>> might be making my own object a dirty one, because castor isnt aware of >>>> the >>>> change in the database. So logically i tried to set the the dirty >>>> attribute >>>> in the mappingfile to ingnore, but with no effect (this also means that >>>> my >>>> theory about the ID is not correct as well). >>>> >>>> I dont have a clue what could be wrong. To complete this post, i ll add >>>> the >>>> pieces of code where all this stuff happens. >>>> >>>> ********************** start of code ********************* >>>> >>>> activityList.getList().addSelectionListener(new >>>> SelectionListener(){ >>>> public void widgetSelected(SelectionEvent event){ >>>> MessageBox msgbox = new >>>> MessageBox(site.getShell(),SWT.ICON_INFORMATION|SWT.YES|SWT.NO); >>>> msgbox.setMessage("Are you sure you wish to >>>> start this activity?"); >>>> int msg = msgbox.open(); >>>> if(msg == SWT.YES){ >>>> >>>> if(currentPerformance != null){ >>>> endCurrentPerformance(); >>>> } >>>> currentActivity = >>>> (Activity)activityList.getElementAt(activityList.getList().getSelectionIndex()); >>>> >>>> status.setText(statusText+currentActivity.getName()); >>>> >>>> logActivity(); >>>> >>>> } >>>> } >>>> >>>> >>>> private void logActivity(){ >>>> currentPerformance = new Performance(); >>>> >>>> currentPerformance.setActivityID(currentActivity.getActivityID()); >>>> currentPerformance.setUserID(Application.conn.getCurrentUser()); >>>> currentPerformance.setStart(new Date()); >>>> currentPerformance.setStop(null); >>>> >>>> >>>> Application.conn.getAccess().createPerformance(currentPerformance); >>>> >>>> System.out.println("THE TIMESTAMP OF THE PERFORMANCE OBJECT: >>>> "+currentPerformance.jdoGetTimeStamp()); >>>> } >>>> >>>> private void endCurrentPerformance(){ >>>> currentPerformance.setStop(new Date()); >>>> >>>> System.out.println("THE TIMESTAMP OF THE PERFORMANCE OBJECT WHEN >>>> UPDATING: >>>> "+currentPerformance.jdoGetTimeStamp()); >>>> >>>> >>>> Application.conn.getAccess().updatePerformance(currentPerformance); >>>> >>>> System.out.println("UPDATE COMPLETED"); >>>> } >>>> >>>> ******************** end of code ********************** >>>> >>>> As you can see, all the activities are contained in a listviewer. When >>>> i >>>> click an activity, i want to make sure that the user didnt accidently >>>> clicked it, so i ask to confirm with a dialogbox. If there is a >>>> currentPerformance, i update it in 'endCurrentPerformance', if not, i >>>> just >>>> create a new Performance in 'logActivity'. >>>> >>>> In my opinion this is a very strange situation. The errormessage >>>> indicates >>>> that there is an invalid object timestamp. I know that when i create a >>>> new >>>> object, the timestamp has to be 0, as an indication that the object is >>>> a >>>> new >>>> one. Castor changes the timestamp, so the object will not be forgotten. >>>> >>>> I compare the timestamp value with the original one just before >>>> updating, >>>> and they are exactly the same. >>>> >>>> In my application i use the same variable name to instantiate a new >>>> Performance. But since instantiating means assigning a new reference to >>>> the >>>> variable, it can not be that the new object has the timestamp of the >>>> object >>>> that was previously referenced by the same variable. >>>> >>>> Any help on this matter would be very much appreciated. >>>> >>>> greetings, >>>> >>>> Noc2 >>> -- >>> >>> Syscon Ingenieurbüro für Meß- und Datentechnik GmbH >>> Ralf Joachim >>> Raiffeisenstraße 11 >>> 72127 Kusterdingen >>> Germany >>> >>> Tel. +49 7071 3690 52 >>> Mobil: +49 173 9630135 >>> Fax +49 7071 3690 98 >>> >>> Internet: www.syscon.eu >>> E-Mail: [EMAIL PROTECTED] >>> >>> Sitz der Gesellschaft: D-72127 Kusterdingen >>> Registereintrag: Amtsgericht Stuttgart, HRB 382295 >>> Geschäftsleitung: Jens Joachim, Ralf Joachim >>> >>> --------------------------------------------------------------------- >>> To unsubscribe from this list please visit: >>> >>> http://xircles.codehaus.org/manage_email >>> >>> >>> >> > > --------------------------------------------------------------------- > To unsubscribe from this list please visit: > > http://xircles.codehaus.org/manage_email > > > -- View this message in context: http://www.nabble.com/Sql-timestamp-type-and-the-castor-cache-timestamp-tp14370195p14414251.html Sent from the Castor - User mailing list archive at Nabble.com. --------------------------------------------------------------------- To unsubscribe from this list please visit: http://xircles.codehaus.org/manage_email
