[jCharts-users] RE: ChartProperties cp = new ChartProperties() throws exception (Unix)

[Steven M S. <sms...@us...>]

An answer to the question

RE:  exception Cannot connect to X11 window server
at  ChartProperties cp = new ChartProperties() throws exception (Unix)
when jCharts run from cron (disconnected virtual machine).

It is not unusual for chart image generation software to
require access to an XServer when run under Unix.  This is
because of Java, specifically graphical objects (i.e. charts).
In Unix, Java's graphics libraries (the Java AWT) are
implemented on top of XWindows/Motif graphics libraries.
These XWindows/Motif graphics libraries require an XServer.

The need to make charts on Unix machines that do
not have Xservers on them is common.  Some machines
are headless (a machine without a monitor/mouse/keyboard attached)
Or you may be wanting to generate charts automatically,
using cron, without haveing to specifically be logged-in.

A solution to this problem is to run a virtual X Server.
A virtual X server can run on a machine without any display
hardware.  It can also peacefully co-exist with other XServers
that may be running on the same computer.

One common XServer is Xvfb "a virtual frame buffer XServer" from
the X consortium.


Regards,
   Steven M Sombar/Austin/IBM@IBMUS       W5OHM
   smsombar@us.....
   Phone 512-838-3353