how to write a java program, which can excute a jar file

[kai2005]

hi all,

I have finished a java program, now someone give me an executable jar file with source code, and want integrate this jar file in my java program.

My Idea is I write a JDialog Object as ProgramChooser, which has some some radio button. When someone choosed an item and clicke OK button, then a choosed program will be actived. For example 3 radio buttons: 1) program1 2) program2(for a jar file) 3) program3

when someone choosed 2. radio button and click OK, then run this jar file.

But which java api?

 

[sedj]

If you have the jar file and source code, why execute it ?
I would have thought you could just call whatever code your wanted to by invoking the desired class.

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[kai2005]

Hello sedj,

I am not sure, whether you have understand me.

You should know, I have finished Programm 1, and then was told, that in Programm 1 will an another Programm be integrated.

Now I have two Choices. One is rewrite Programm1 with using the source code of Programm 2. Another Choice is just invoke the jar file of Program 2. And I think the second choice will be simple.

So I want to know, which api I can use to invoke a jar file.

 

[sedj]

I do understand you - I'm just saying I don't thing it is the right thing to do.

In any case, you don't use an API to run an executable jar file - you just execute it using :

java -jar myjar.jar MyMainClass

You can run system command like this :

Process p = Runtime.getRuntime().exec("java -jar myjar.jar MyMainClass");
p.waitFor();

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[stefanwagner]

Well, but if the jar-file is already part of the classpath, you would just call

MyMainClass.main ();

to start it.

seeking a job as java-programmer in Berlin:

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[sedj]

That's what I suggested in the first reply

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[stefanwagner]

Sorry - I see.
But I don't understand what the advantage could be to call Runtime.
I only see a lot of drawbacks.

seeking a job as java-programmer in Berlin:

http://home.arcor.de/hirnstrom/bewerbung

 

[sedj]

Well I agree with that !

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[kai2005]

Hello sedj,
Hello stefanwagner,

thank you all for the reply.
It do work now.

The jar file will be actived after the statements
Process p = Runtime.getRuntime().exec("java -jar myjar.jar MyMainClass");
p.waitFor(); executed. But after I close the jar file, I can not direct back to the last Program, that mean, only when I click it on the windows ProgramSymbolBar.

How can it be automaticly reactived without clicking it on SymbolBar.