Detecting another JVM instance

I have developed a Java desktop application that works fine if there is only one instance of it running. When a second instance of it is opened, problems occur. Is there any way to detect that another instance of an application (or JVM) is currently running? If I could detect this, I could display a message informing the use that they already have an instance running and to close one of them...
Any guidance here would be greatly appreciated.

Traditionally done
-with a ServerSocket bound to a specific port
-with a lock file (on *nix often with the pid).

Similar Messages

Calling a method in another JVM instance

I know you can use RMI to call the methods from classes across the network, but if the class is on the same machine, just in another JVM instance, is there a way to bypass the network layer and have the JVMs communicate directly with each other?

Its not so much the overhead, as having the
flexibility, to not have to modify firewall rules
which disallow loop back traffic and most other non
http (port 80) traffic if the production server is
set up that way.You're coding to interfaces anyway, have a factory return either an RMI object which does the actual RMI work, or just a vanilla one if you're just running locally. As far as I know, there isn't a way to entirely circumvent the socket layer with RMI. Anyone know any different?

Certain application's JVM instance

Hello,
I didn't really know in what section to post this thread, so I figured this was the best one. If it is in the wrong section, notify me, and I will post it in the correct section.
I am making an application in C which requires getting the process ID of a specific JVM instance. The problem isn't getting the process ID, but it's differentiating a VM instance from another. How would I go upon doing this?
Thanks

Wow! Can't get much easier than that :)
Thanks alot!
EDIT: The application I am trying to get runs as an applet. So unfortunately, every applet prints: sun.plugin2.main.client.PluginMain
Any ideas?

How to Shutdown JVM Instance

I have a java program which I start(run) from console, the program acts as a listener so it never exits, however I want to be able to it shutdown by running a batch file or running a script which is basically in another console window, any ideas how can I shutdown a JVM instance from another console window.
*Note: Pressing <Ctrl+C> in the application console is not an option.

Maybe have a socket listener on a certain tcpip port.
Then send a message to that tcpip port... one which your original app will interpret as a "shutdown" signal.....
regards,
Owen

Possible to create a pool of JVM's from another JVM's ?

Hi all,
currently I'm researching on a small task where a native "black box" C++ library needs to be integrated into Java, developing some kind of JNI-based wrapper. I've done this already with SWIG two times before, worked quote well, but this time it's different: The wrapper will be used from a multiuser application (i.e. various parallel working calls) but the native library is not only not threadsafe, but it also utilises static variables at central places.
My idea is the follwing
1) The standard solution part: create a wrapper application in it's own JVM which exposes the native interfaces as Java interfaces
2) Instantiate multiple of these wrappers as separate processes (i.e.: separate JVMs, the "inside JVM") from another JVM ("outside JVM").
3) The outside JVM uses the multiple instances in a kind of "round-robin" or "next free" pattern to assign new calls to a set of "worker JVM".
The interesting part of this question is in 2): How can I instantiate a [set of] new JVM from inside another JVM so the inside JVM are really their own processes? Only by having the multiple instances as separate processes I can overcome the problem of the single-threaded native lib becoming "quasi-multithreading"?
The easiest approach would be likely to start new JVMs using the "Process" object and to start new JVMs with the usual shell scripts. But I'd like to have some more elegant ,-)) Is there any way to have this done in a better way?
Thanks a lot,
Soeren Gerlach

Presumbly locking wouldn't work?Not really: Locking would mean that only one client/person could use the library using the Java wrapper. That in fact is the shortcoming I'd like to overcome by instantiate multiple processes.
Thanks,
Soeren

Automatic Sales order creation from IDOC generated in another SAP instance?

Hi,
I have been trying to create Sales ordes in a seperate SAP instance, through the Purchase order generated in another Instance.
The Purchase order generated, passes the informtion through an IDOC to another SAP instance, I am getting the following error
" VKORG, VTWEG, SPART cannot be determined for customer 0000001000 ,Vendor000200038 "
It is Message No VG204 , Status Record 51
Please help to solve the problem.
Regards,
Chamandeep

SAP Xpert friends,
I really need help in figuring out this error I get when I send an IDoc from external system to SAP.
Here is what I do....
create empty idoc of type ORDERS01
idoc.MESTYP = "ORDERS";
idoc.SNDPRN = "1171";
idoc.SNDPRT = "KU";
idoc.MANDT = "400";
idoc.SNDPFC = "AG";
idoc.MESCOD = " ";
idoc.MESFCT = " ";
idoc.TEST = " ";
create segment of type E1EDK01
add field MENGE with a value
add segment e1edp01 to idoc
create segment of type E1EDP19
add field QUALF with a value to segment
add field IDTNR with a value to segment
add segment E1EDP19 to idoc
send idoc
When I check WE02 in SAP, I can see the idoc, but
get this error
Here are all the STATUS RECORDS
<b>50 IDoc added
64 IDoc ready to be transferred to application
62 IDoc passed to application
51 Error: Application document not posted
    <i>VKORG, VTWEG, SPART cannot be determined</i>
    for customer 0000001171 , vendor</b>
I checked on Internet and found that VOE2 can be used to setup ... this is what I have in VOE2
Customer    Vendor SOrg     DChl   Dv
1171        0000001171       1000   00
Thanks for help...

My iPhone's bluetooth is not able to detect another iPhone iOS 7.0.6. (latest)

my iPhone's bluetooth is not able to detect another iPhone iOS 7.0.6. (latest)

Speakers, keyboards, headsets, pulse monitors, pebble watches, cars with hands free systems, etc.
Are both phones signed into itunes under the same user?
are you trying to transfer purchased music to someone else in violation of itunes terms of service?

Multiple JVM instances

Dear all,
I am trying to create multiple JVM instances using createJavaVM(...) but I can't do it. When I try to create the second instance, the function returns an error.
Does anybody know about getting multiple JVM instances running??
Thanks in advance,

Hallo,
createJavaVM(...) trys to create a JVM in your current
process, so I am not surprised that you get an error
the second time round, because there is already a JVM
in the process. If you want multiple JVMs, each needs
to be in its own process.
Why do you want to create more than one JVM in your
process? The JVM is multithreadable, and you can start
more than one thread in the JVM. Would that do what
you want?I need multiple instances because my application needs nearly 2Gb of memory and the maximum heap I get is 1700 Mb. I think with multiple instances, I'll get it.
Do you know about getting a bigger heap??
>
David Singleton
[email protected]

Regarding code to call & control a JVM from another JVM

hi,
I need to communicate from one JVM to another JVM. I know it can be done using RMI. But, i don't to write in code.If any one had tried it, please reply me with the code.
Satchi

Hi Satchi,
In my opinion, RMI is complex enough that I don't think you can learn it through a forum. So please allow me to direct you to some Internet resources that I used in order to learn RMI, and I hope will help you to as well.
[Note: Not in any particular order.]
http://java.sun.com/docs/books/tutorial/rmi/index.html
http://developer.java.sun.com/developer/onlineTraining/rmi/
http://java.sun.com/products/jdk/rmi/
http://www.dickbaldwin.com/tocadv.htm
http://mindprod.com/jglossrmi.html#RMI
http://jinx.swiki.net/263
Hope this helps.
Good Luck,
Avi.

Import data backup into another DB instance

Hello all.
I need to import a Data Backup into Another Database instance. MaxDb version 7.3.
On higher versions of MaxDb I performed this operation without any problems (http://help.sap.com/erp2005_ehp_04/helpdata/EN/43/d5ebc2c9ed3ab3e10000000a422035/frameset.htm).
For this version of MaxDB I have such problem:
the commands don't coincide with help description, I define backup template, transfer DB instance to admin state, open utility session and try to srart recovery (there is no command db_activate RECOVER <template>)
dbmcli on Q46>util_connect
OK
dbmcli on Q46>recover_start DEMO
ERR
-24988,ERR_SQL: sql error
-903,Message not available,blockcount mismatch
What I can do? How can I start recover from data backup from another DB on this version of MaxDB?

I have tried to perform backup of original system and recovery to another database one more time.
There is the another error:
dbmcli on Q46>recover_start DemoD46_recover
ERR
-24988,ERR_SQL: sql error
-3014,Invalid end of SQL statement

Multiple JVm instances error in iplanet 4.1

the error message is :
info ( 1184): JVM instance has already been created within the process, numVMs=1
I have an NSAPI filter which uses JNI and will create an individual JavaVM.
I understand in the process no more than 1 JavaVM shall be initialized yet I can't find a way to attach my NSAPI filter to the JavaVM created by the iplanet server.
Does anybody has any idea how to solve this?

Thanks for your reply. It seems odd though that IWS 4.1 seems to work fine w/sdk1.4.1 on my WinNT machine???

Chang system userid/password for another server instance

It it possible to change the system userid/password for another server
instance. If so , how ?
I would like to allow certain groups to be able to start and stop ONLY their
server without giving out the system account.
Thanks in advance!

the relationship between the infrastructure nodes and the application server nodes is a one to many relationship. The infrastructure home should be the only home that the EMWebsite service has been started for.
the user to log in to em console is ias_admin/<password> if it does not accept the password that you set for this user then try it with caps lock on as you may have had it one when setting the password.
As 9ias release 2 has been designed with a multiple machine install in mind, if you install more than one instance (multiple oracle homes) on the server then you will end up with multiple apache processes and oc4j processes. This means you will be able to connect to 2 apache server homepages under different ports. That is why you get the same page.

Trying to reinstall Acrobat Pro X from disc onto win 8.1 system. (Previous installation got corrupted) Continually getting message 'Acrobat has detected another process which has not yet completed-'. Have now closed system both cold (full shutdown) and wa

Trying to reinstall Acrobat Pro X from disc onto win 8.1 system. (Previous installation got corrupted) Continually getting message ‘Acrobat has detected another process which has not yet completed…’. Have now closed system both cold (full shutdown) and warm (restart) over 10 times. Every time I go to reinstall I get message.

I would run http://labs.adobe.com/downloads/acrobatcleaner.html and delete any Acrobat folders that have been created, then try again. Be sure to log in as the administrator and disable anti-virus when you have problems like this.

Launching another VM instance using Runtime.exec()

Hi,
I have two separate Swing applications, say A and B. I need to launch B from A using Runtime.exec() - essentially I am launching another VM instance from one VM. I am encountering strange problems - B's main window comes up, but GUI doesn't update; sometimes B comes up and GUI updates, but huge memory leaks happen. All the problems with B go away once A is shut down. It almost looks like both the instances of VM are sharing (or competing for) the event thread. Any comments will be of great help. Thanks.
note: There is no problem launching B if A is a console java application (i.e. no Swing GUI).

I have recently had the same problem, especially with the part where it seems like the two applications are sharing or competing for the same event thread. Sometimes my application B hangs like it is stuck waiting for an event. Sometimes I can get it to unhang by moving the app window around or minimizing it. If it does break free, all the queued events occur in rapid succession. Anybody have any clue what's going on here? It's pretty annoying.

DBMS_DATAPUMP import into another database instance

Hi there,
i have a quick question as i didn't find an answer in my oracle documentations...
I use a PL/SQL program in a Oracle Application Express (APEX) application to import a dumpfile via the dbms_datapump API. It`s no problem to import it into the database on which APEX runs and i'm connected to in my application, but now i want to start an import of the dumpfile into another database. I know that it is possible in the commandline interface of the data pump tool to import a dumpfile from one database instance to another with a connect identifier in the connect string.
Could someone tell me where i have to put these information in the datapump API?
Fennek

Hi,
thx for the replies...
I think damorgan is right, in the meantime i read somewhere else that you appearantly cant start an import into another databse instance out of PL/SQL...
Well, maybe i will try to use dbms_scheduler to start an external script which starts the import tool like apex_disco wrote...
Fennek

Detecting another JVM instance

Similar Messages

Maybe you are looking for