only one instance

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Chameleon - 30 Oct 2005 12:11 GMT

I want only one running instance of my app.

There are 2 methods:

1. sockets
2. locking files (I prefer this)

But my big problem is this:

When I run the 2nd instance of App with a file parameter:

my_app.jar a_file.txt

I want to pass "a_file.txt" to 1st instance for opening and then 2nd
instance terminate.

How can I do this?

sorry for my english
and thanks

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Thomas Hawtin - 30 Oct 2005 12:48 GMT

> I want only one running instance of my app.

> 1. sockets
> 2. locking files (I prefer this)

> When I run the 2nd instance of App with a file parameter:
>
> my_app.jar a_file.txt
>
> I want to pass "a_file.txt" to 1st instance for opening and then 2nd
> instance terminate.

The obvious solution is to use the socket method of running a single
instance of the app. The second app then connects to the socket and
transfers the filename.

Tom Hawtin

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Unemployed English Java programmer
http://jroller.com/page/tackline/

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steve - 30 Oct 2005 22:15 GMT

>> I want only one running instance of my app.
>
[quoted text clipped - 13 lines]
>
> Tom Hawtin

I sometimes get problems with the socket approach, if the main app shuts down
for some reason (and does not kill the signaller),the socket app ( running in
another thread) holds the jvm open ,and requires a 3 finger salute.
otherwise it prevents the user from re-starting a new app.

the another way is to get the program to write a java "temp" file to a
directory with no other file in.

then when you start the app, count the files in that directory.
( i have not yet seen java NOT clean up it's temp files)

Do not create a "Normal user file", but a Java TEMP file.

Steve

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only one instance

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