[OpenJDK 2D-Dev] [PATCH FOR REVIEW] fix for fontmanager when no fonts are installed - RHBZ#862355,

Phil Race philip.race at oracle.com
Mon Nov 12 20:43:38 UTC 2012

Well this seems like a really narrow use case for an extremely rare system
misconfiguration. It wouldn't help the 99.999% of apps which expect to
kick off AWT or Swing.

And can you ensure that nothing in the app, or in the implementation makes
the (reasonable) expectation that there are other fonts installed ?
The most you could do is render to a BufferedImage or similar using the 
loaded font. The default logical font installed on a SG2D will be backed 
by a non-existent
physical font, so you'd need to swap that in sooner rather than later.

At some point you have to say that if JRE or system components are missing,
then the source of the problem is what you should fix rather than make the
JRE work around it.

If you do want to try something, then in this case you get a much more 
runtime by providing a default font that the JRE can ensure is available so
that the other 99.999% of apps can get by.

The "Oracle" JDK gets by in this case precisely because it has a real 
physical font
to fall back on.


On 11/12/2012 12:29 PM, Mario Torre wrote:
> Hi Phil,
> I believe that the underlying problem here is that it should be legal 
> to create a font from a file, even if the FontManager doesn't have any 
> fonts installed.
> So, code like the one in the example:
> public class Test {
>      public static void main(String[] args) throws Exception {
>          Font.createFont(Font.TRUETYPE_FONT, new File("example.ttf"));
>      }
> }
> When passed a real, valid font (example.ttf in this case) would still 
> fail with the old code, and instead would work with the given patch 
> (at least, I think this is the idea here, Jiri can probably explain in 
> more details his intentions?).
> Cheers,
> Mario
> 2012/11/12 Phil Race <philip.race at oracle.com 
> <mailto:philip.race at oracle.com>>
>     Hello Jiri,
>     Doesn't this just move the point of failure to a bit later ?
>     I can't see how having zero fonts on the system is survivable for an
>     app that uses fonts. That's the principal reason we haven't tried
>     to do something like this already.
>     When facing system configuration issues maybe we just need to
>     print a better message for the exception such as
>     throw new InternalError("Can't find any fonts installed on this
>     system.");
>     Or make the default font more configurable and distros could ship
>     one in jre/lib/fonts.
>     BTW it appears you are only trying to solve the problem for
>     Linux/Unix.
>     Nothing for Windows or OS X.
>     -phil.
>     On 11/12/2012 10:07 AM, Jiri Vanek wrote:
>         Hi!
>         This is attempt to fix
>         https://bugzilla.redhat.com/show_bug.cgi?id=862355
>         The patch is introducing new exception
>         src/share/classes/sun/font/NoFontsFoundException.java, which
>         is thrown from
>         /src/solaris/classes/sun/awt/X11FontManager.java    instead of
>         null pointer exception when no fonts are found on system.
>         Exception is then catch in
>         src/share/classes/sun/font/FontManagerFactory.java, and in
>         this case it returns (and not caching the instance of it)
>         dummy font manager instead of continue in failure.
>         the dummy manager do nothing, except that it is able to create
>         java.awt.Font in same way as SunFontManager is doing, but is
>         not doing any caching.
>         To avoid duplicate code with
>         src/share/classes/sun/font/SunFontManager.java, i have
>         extracted code from method createFont2D to new method here -
>         prepareFont2D - which is responsible for creating font until
>         caching..
>         Best regards,
>           J.
>         webrev
>         http://jvanek.fedorapeople.org/oracle/jdk8/webrevs/fontProperties/
>         with test  (although it will probably need some tuning and I'm
>         not sure where is the best place for it)
>         http://jvanek.fedorapeople.org/oracle/jdk8/webrevs/fontProperties/test/src/nofontsreproducer/
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