Experiences developing iViews with JSP tags

Question

Hi,
has anyone experiences in the development of iViews using JSPs and the JSP tags ? Especially the useBean tag... I think it should be no problem to store beans in the session. If I want to share the bean among iView is it enought to synchronized each method of the bean ?
Thanks

Answer 1

Hi O.,
please, before going on guessing around what synchronization means, read some tutorial, that's what the link was thaught for. It is no problem at all not to know this topic, it's definitely some more advanced topic within the language, but it doesn't help if you don't know it to guess how it <i>could</i> work/behave.
> if I declare all getters and setters of the bean with
> synchronize I avoid the issue of inconsistent data
Once again: For pure getters and setters this sentence is definitely wrong. As long as complex class members are not manipulated / accessed concurrently, there is no need for synchronization (within the class).
> thread 1 sets a value a concurrent thread 2
> could read the data and would get a not actual value...
> if I synchronize the get and set, thread 2 will be
> able to invoke the getter after thread 1 finished the
> setter.
Once again: You don't have it in your hands which thread comes first. And synchronizing a method only means that a thread calling this method will run through it as an atomic operation, no other thread will disturb. But getters and setters normally are atomic, you cannot reach more... If a thread calls two (synchronized) methods of the same object, between these two calls, "the race is open again...".
A good example is http://www-106.ibm.com/developerworks/java/library/j-threads1.html
See the example at the end of this link, that's somehow just what we are talking about. The solution would be to synchronize the <i>setFoo(getFoo() + 1)</i> itself (for example with the bean object as locker). Whereas the synchronization of the methods is superfluous (and time consuming).
Hope it helps
Detlev