Program Auto Restart

[pointertowhat]

How do you make a java application shutdown and automatically restart itself?

The reason for this is I have an application I maintain - it's run from a network drive and sometimes the users leave an instance running for months at a time. When I release an update I would like each instance to display a dialog letting the user know the app must be restarted, and just to make sure they do I want the app to shutdown and restart itself automatically.

 

[Diancecht]

That will strongly depend on how the application works and what do you mean with restart. The problem is a non-trivial one and can have a lot os sollutions:

- Make the application run as a windows service
- Implement a change listener and clear the app



Cheers,
Dian

 

[pointertowhat]

Dian,

The windows service solution wouldn't be practical and also it's unfamiliar territory for me.

What do you mean by "Implement a change listener and clear the app" - I can see how I can use a change listener and shut down the app when needed - it's the restart part that gets me.

 

[Diancecht]

If you're planning to reload jar files, you cannot do it (AFAIK) inside the Java application, you will need to use something external to shutdown and lauch a new instance.

I'm not sure what will happend if you use a Runtime.exec() call to run a bat program and then a System.exit() to close current instance ...

Cheers,
Dian

 

[TonHu]

You could run the from a batchfile or shellscript, returning an errorlevel to indocate it should loop and restart the app, like in runthisapp.bat

@echo off
:loop
echo Starting thisapp...
java -jar thisapp.jar
if errorlevel 5 echo Update-restart...
if errorlevel 5 goto loop
if errorlevel 1 echo Something bad happened, code: %ERRORLEVEL%
echo Done.

HTH
TonHu

 

[stefanwagner]

I don't know what a windowsservice is, but on linux, you can start it as a linuxserice.

with nohup, you can start it in a way it get's automatically restarted after shutdown, which is a very easy solution, but needs a different approach on windows, maybe not on solaris, and I don't know for mac.

An OS-agnostic approach would be a wrapperapplication with an own ClassLoader, because the normal classloader will not load a second, updated instance from a file.

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