I want to restrict instantiation of a class to one time only.

I am developing a java application. The requirement is that only one instance of a class/application should run. Any attempt to load application twice be restricted displaying some warning message.
Please help me on this problem.

There are several ways to do this, I believe. One is
to create a specific temporary file in the file
system. as soon as the application starts. First
thing to do when the app runs (in the main method)
would be to check if that file exists. If it does,
exit the app. If not, create it then continue with
the rest of the application.
there is a second method by opening up a port or
socket. I am not familiar with this, but if you
search the forum you should find an answer...I would use ports. When an process stops it's guaranteed to release port resources. "temporary" files
can be left behind, to confuse your app the next time you run.
And just to be clear: OP, you wanted at most one copy of the app running on a given machine,
or one copying running anywhere on a network of machines?

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How to restrict user marking same events in multiple times.

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Now in my application if any user goes back to the question displaying page after submitting same questions, he can change the answer selected in first attempt and submitting again the test, the result are stored in final table. I.e. for same question no. user is now able to answer in two times. I want to restrict user for answering test in second times.
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Hi Hari,
with you suggested logic can i restrict user marking one question in multiple times,
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Edited by: HARSHAL_GURAV on Aug 20, 2008 12:15 AM

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I have one Webi report which has 3 @prompts for Purchase order number, Serial number and Sales order number, User is supposed to enter any one value as these prompts are on OR condition. For example, I enter Serial number and rest as '*'.
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How to apply this functionality at Report level?

Hi,
when you say disable the prompts when user selects one of the Purchase order number, Serial number and Sales order number. what did u want? say user selects the serial number do u want to pull all records pertaining to selected serial number along with all the records related to the other fields((Purchase order number,Sales order number)) or when the user selects the serial number did u want the report to run only for the serial number selected but ignore the remaining prompts by not fetching any records for those prompts ?
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My Client wants to restrict appearing used PO Line items in MIRO

Hi Gurus
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Hi
Even if I set Final Invoice Indicator in MIRO and booked invoice against the PO systems is showing blank line items (Amt & Qty are blank) in MIRO agaisnt the PO.
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Hi Experts,
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There is no solution for you in standard you have to develop something yourself.
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thanks in advance.

Dear Friend,
Just go through the Sample code of that BADI.
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With Regards,
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Want to restrict user form putting any value in condition in po

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ply help on this matter.
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Hi,
To restrict any manual entries for a Condition type, In that condition type under Changes which can be made maintain 'D' for Manual entries option.
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Want to restrict data in T.code MD4C

hi friends,
i want to restrict output of T.Code MD4C in which it displays all materials
for one SO but i want to display only FERT HAlB and RAW materals. how should
i do it. there is one badi MD_ADD_COL_OVERVIEW (Display of Additional
Columns in the Material Overview ) . is it write place to do it if yes i
never use BADI so kindly can u send some information about badi and how to
use it.
thanks in advance.

hi,
BADI you mentioned is not present in Definition view ie se18.
To implement BADI using se19 you need to check 1st wether it is present in definition view.
Once you find appropiate BADI you will have to write code in its interface method.
For this purpose you should be aware of ABAP OOPs concept.
Regards,
SUDHIR

N00b query: Why would anyone ever want to define their own Exception class?

I've been reading thru my Java textbook for the past couple hours.
Exceptions are a wonderful thing. I already found several instances where I could've implemented try/cacth in my earlier programs.
Anyway, getting back to the point. My question is, can someone give me a realistic situation/example where a custom Expcetion class is REQUIRED? (the key word here is "required"!)
I can see why someone would want to have his own Exception class..... e.getMessage() as custom error messages are SO DAMN COOL!!!!!! :P
hehe
But seriously, if you are making intermidiate/advanced Java programs, would you ever REQUIRE to make your own Exception class? Afterall, even a custom made Exception class always "extends" from a pre-defined Java class, right?
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try{
throw new CustomException;
catch (IOException e) { }
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I know I know, I am so naive. Enlighten me >.<

Sure. Say you want to have a system where you want to include a custom error code which maps to some internationalized error messages. You would create an Exception subclass with a field to hold that value separate from the normal "default" message. Then you could throw that exception in all your code. Other code can catch it as a plain Exception if they want and use the "default" message, which is okay if they don't really care about the error code.
I don't think you are ever "required" to make your own exceptions. I have done so, but I don't often. It depends. See, there are plenty of Exception subclasses in the standard packages, and most of them cover many of the things you need. So more often if I'm throwing an exception, I'll be using the already existing ones, like IllegalArgumentException or IOException (whatever is relevant to the code).
Yes, you can do what you did below with CustomException. However the reason you might do that is cuz you really want to do this:
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} catch (CustomException ce) {
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} catch (IOException ioe) {
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Usually when you use an exception class it's a named class that relates to some condition. It may hold additional information besides the standard message, but I think most of the time it's just the class name which describes the problem. And if there isn't one that describes the problem that you're code might encounter, then create a subclass.

I have a problem how can I solve it I want give permissions to groupA to edit the people picker and I want to restrict groupB to edit the people picker what is the solution boss.. in InfoPath form is it possible..

i have a problem how can I solve it I want give permissions to groupA to edit the people picker and I want to restrict groupB to edit the people picker what is the solution boss.. in InfoPath form is it possible..

Hi,
To hide/disable controls based on user group in an InfoPath form, a solution is that we can call User Profile Service to check the group of current user, then hide/disable
specific controls by setting some rules in form.
Here is a demo with steps in details would be helpful to you:
http://blog.symprogress.com/2011/05/infopath-list-form-hidedisable-fields-based-on-sharepoint-group-membership/
More information about checking if a user is a member in a SharePoint group within web InfoPath 2010 forms:
http://www.hishamqaddomi.ca/spg/index.php/sharepoint-2010/infopath-2010/65-checking-if-a-user-is-a-member-in-a-sharepoint-group-within-web-infopath-2010-forms
Thanks
TechNet Community Support
Please remember to mark the replies as answers if they help, and unmark the answers if they provide no help. If you have feedback for TechNet Support, contact
[email protected]

Want to restrict infotype maintainance 9(Bank Detail) for withdrawn emp

Hi Experts,
I want to restrict the maintainance of infotype 9 for withdrwan employee, either this has to be done through configuration or writing code in module pool of infotype 9.
Thanks in Advance.
Regards,
IFF

hi,
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Regards,
Kapil

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Hi all
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Ex:
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Dear Siddharth
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I want to restrict instantiation of a class to one time only.

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