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Posted to users@tomcat.apache.org by "Christoph P.U. Kukulies" <ku...@kukulies.org> on 2015/01/11 12:24:47 UTC
-Djava.awt.headless=true JVM parameter
I'm installing OpenCms 9.5.0 (www.opencms.org) under tomcat 6.0.32 and
during setup I'm getting a warning saying that
"Your system uses components which have not been tested to work with
Alkacon OpenCms. It is possible that OpenCms will not run on your system.
|-Djava.awt.headless=true| JVM parameter or X-Server may be missing.
*You can continue the setup, but image processing will be disabled.*
"
Is this an issue that I can fix with setting Tomcats' startup parameters
(Service under Windows 7)?
--
Chris Christoph P. U. Kukulies kukulies (at) rwth-aachen.de
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Re: -Djava.awt.headless=true JVM parameter
Posted by Thad Humphries <th...@gmail.com>.
On Sun, Jan 11, 2015 at 10:18 AM, Felix Schumacher <
felix.schumacher@internetallee.de> wrote:
> Am 11.01.2015 um 12:24 schrieb Christoph P.U. Kukulies:
>
>> I'm installing OpenCms 9.5.0 (www.opencms.org) under tomcat 6.0.32 and
>> during setup I'm getting a warning saying that
>>
>>
>> "Your system uses components which have not been tested to work with
>> Alkacon OpenCms. It is possible that OpenCms will not run on your system.
>>
>> |-Djava.awt.headless=true| JVM parameter or X-Server may be missing.
>> *You can continue the setup, but image processing will be disabled.*
>>
>
This warning overstates the effect of setting headless to true. You can
still do a lot with AWT and other imaging software. My servlets can, for
example, create a BufferedImage, draw to it, and send the result as a PNG
to the browser. They can uncompress TIFFs with JAI, create TIFF and JPEG
images with Commons-Imaging, create PDFs with iText, and many other imaging
tasks. What they can't do is anything that requires the DISPLAY environment
variable, like get FontMetrics.
I set headless to true on development and test machines because we've found
systems where the Tomcat user does not always have access to the DISPLAY
variable. Other times Tomcat maybe installed on a truly headless server.
But there is still lots that can be done graphically.
> Is this an issue that I can fix with setting Tomcats' startup parameters
>> (Service under Windows 7)?
>>
>> You should be able to set the headless parameter in CATALINA_OPTS.
>
> Regards
> Felix
>
>
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--
"Hell hath no limits, nor is circumscrib'd In one self-place; but where we
are is hell, And where hell is, there must we ever be" --Christopher
Marlowe, *Doctor Faustus* (v. 121-24)
RE: -Djava.awt.headless=true JVM parameter
Posted by "Caldarale, Charles R" <Ch...@unisys.com>.
> From: Christoph P.U. Kukulies [mailto:kuku@kukulies.org]
> Subject: Re: -Djava.awt.headless=true JVM parameter
> Interesting would be though, what headless exactly means and what it has
> to do with graphics.
Basically, it means there is no graphics display on the same machine as the JVM. Setting headless does not inhibit the generation of graphics, dust the direct display of them.
http://www.oracle.com/technetwork/articles/javase/headless-136834.html
- Chuck
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Re: -Djava.awt.headless=true JVM parameter
Posted by "Christoph P.U. Kukulies" <ku...@kukulies.org>.
Thanks, I found it to set the parameter with the configurator.
Interesting would be though, what headless exactly means and what it has
to do with graphics.
I know "headerless" from threaded languages (headerless Forth for
example) and I was thinking
in the context of Java it would be a "headerless" java bytecode, but I
would not have thought it had to do something
with DISPLAY "heads" whatever that means.
--
Chris Christoph P. U. Kukulies kukulies (at) rwth-aachen.de
Am 11.01.2015 um 18:25 schrieb Caldarale, Charles R:
>> From: Felix Schumacher [mailto:felix.schumacher@internetallee.de]
>> Subject: Re: -Djava.awt.headless=true JVM parameter
>>> |-Djava.awt.headless=true| JVM parameter or X-Server may be missing.
>>> *You can continue the setup, but image processing will be disabled.*
>>>
>>> Is this an issue that I can fix with setting Tomcats' startup
>>> parameters (Service under Windows 7)?
>> You should be able to set the headless parameter in CATALINA_OPTS.
>
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RE: -Djava.awt.headless=true JVM parameter
Posted by "Caldarale, Charles R" <Ch...@unisys.com>.
> From: Felix Schumacher [mailto:felix.schumacher@internetallee.de]
> Subject: Re: -Djava.awt.headless=true JVM parameter
> > |-Djava.awt.headless=true| JVM parameter or X-Server may be missing.
> > *You can continue the setup, but image processing will be disabled.*
> >
> > Is this an issue that I can fix with setting Tomcats' startup
> > parameters (Service under Windows 7)?
> You should be able to set the headless parameter in CATALINA_OPTS.
The OP stated that it's running as a Windows service, so environment variables aren't useful. Use the tomcat6w.exe utility to set any necessary JVM options.
- Chuck
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Re: -Djava.awt.headless=true JVM parameter
Posted by Felix Schumacher <fe...@internetallee.de>.
Am 11.01.2015 um 12:24 schrieb Christoph P.U. Kukulies:
> I'm installing OpenCms 9.5.0 (www.opencms.org) under tomcat 6.0.32 and
> during setup I'm getting a warning saying that
>
>
> "Your system uses components which have not been tested to work with
> Alkacon OpenCms. It is possible that OpenCms will not run on your system.
>
> |-Djava.awt.headless=true| JVM parameter or X-Server may be missing.
> *You can continue the setup, but image processing will be disabled.*
>
> "
>
>
> Is this an issue that I can fix with setting Tomcats' startup
> parameters (Service under Windows 7)?
>
You should be able to set the headless parameter in CATALINA_OPTS.
Regards
Felix
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