RE: Can't connect to X11 window server using '0:0' as the value ofthe display and now java.awt.HeadlessException
Hi, I would say that Xvfb does _not_ connect to your display adapter - the v stands for virtual, ie it's not a real frame buffer as in a video card - it's a virtual one in your systems normal memory. It's specifically for taking the place of a display adapter when your server doesn't have one. We always used to use this on sun E250s without a display adapter, but now we use headless as it's more reliable. Andy > -Original Message- > From: p niemandt [mailto:[EMAIL PROTECTED] > Sent: 20 March 2003 21:47 > To: Tomcat Users List > Subject: Re: Can't connect to X11 window server using '0:0' as the value > ofthe display and now java.awt.HeadlessException > > > Yep: Done correctly, this is probably the more 'correct' solution, but, > and I'm probably opening myself to a lot of flamebait, but I do suspect > that using something like Xvfb might give some advantages that using > headless won't. For example, and I'm just guessing, but I think that > 'headless' is purely a software solution, while Xvfb might be connected > to your display adaptor, and therefor might be faster or less of a drain > on your system resources. > > { > But, like I said, I have no documentation to back up this statement, > this is purely a guess and based on my personal findings: If anybody > else knows differently, I would be very interested to know more, as I'm > doing a lot more graphics orientated servlets, that usually run on > headless boxes } > > > > On Thu, 2003-03-20 at 20:36, Micael wrote: > > For me the easiest thing was just to provide the right command > line options > > (java.awt.headless=true) when I started up Tomcat. > > > > At 02:27 PM 3/20/03 -0500, you wrote: > > >At 07:18 PM 3/20/2003 +, you wrote: > > >>ok: there is another solution to the headless thing: (I wrote a > > >>graphical servlet that runs on a linux box without X, and had the same > > >>problems: The headless seemed to work, well, kinda, but not to my > > >>liking): So I went the xvfb route: This is a virtual frame > buffer to can > > >>install on a linux box that emulates an X session, which then kinda > > >>solves all the graphical problems in one step. You set the xvfb to the > > >>resolution required and just start and forget about it. > > >> > > >>Worth I shot, I'd say, and might safe you hours of frustration [It did > > >>me ;-) ]. > > > I had tried xvfb and had some difficulties. Any pointers? > suggestions? > > > > > >Thanks, > > >Glenn > > > > > > > > > > > >- > > >To unsubscribe, e-mail: [EMAIL PROTECTED] > > >For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > > > > > > LEGAL NOTICE > > > > This electronic mail transmission and any accompanying > documents contain > > information belonging to the sender which may be confidential > and legally > > privileged. This information is intended only for the use of the > > individual or entity to whom this electronic mail transmission > was sent as > > indicated above. If you are not the intended recipient, any disclosure, > > copying, distribution, or action taken in reliance on the > contents of the > > information contained in this transmission is strictly > prohibited. If you > > have received this transmission in error, please delete the > message. Thank > > you > > > > > > > > - > > To unsubscribe, e-mail: [EMAIL PROTECTED] > > For additional commands, e-mail: [EMAIL PROTECTED] > -- > p niemandt <[EMAIL PROTECTED]> > > > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] > > - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Can't connect to X11 window server using '0:0' as the value ofthe display and now java.awt.HeadlessException
Yep: Done correctly, this is probably the more 'correct' solution, but, and I'm probably opening myself to a lot of flamebait, but I do suspect that using something like Xvfb might give some advantages that using headless won't. For example, and I'm just guessing, but I think that 'headless' is purely a software solution, while Xvfb might be connected to your display adaptor, and therefor might be faster or less of a drain on your system resources. { But, like I said, I have no documentation to back up this statement, this is purely a guess and based on my personal findings: If anybody else knows differently, I would be very interested to know more, as I'm doing a lot more graphics orientated servlets, that usually run on headless boxes } On Thu, 2003-03-20 at 20:36, Micael wrote: > For me the easiest thing was just to provide the right command line options > (java.awt.headless=true) when I started up Tomcat. > > At 02:27 PM 3/20/03 -0500, you wrote: > >At 07:18 PM 3/20/2003 +, you wrote: > >>ok: there is another solution to the headless thing: (I wrote a > >>graphical servlet that runs on a linux box without X, and had the same > >>problems: The headless seemed to work, well, kinda, but not to my > >>liking): So I went the xvfb route: This is a virtual frame buffer to can > >>install on a linux box that emulates an X session, which then kinda > >>solves all the graphical problems in one step. You set the xvfb to the > >>resolution required and just start and forget about it. > >> > >>Worth I shot, I'd say, and might safe you hours of frustration [It did > >>me ;-) ]. > > I had tried xvfb and had some difficulties. Any pointers? suggestions? > > > >Thanks, > >Glenn > > > > > > > >- > >To unsubscribe, e-mail: [EMAIL PROTECTED] > >For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > LEGAL NOTICE > > This electronic mail transmission and any accompanying documents contain > information belonging to the sender which may be confidential and legally > privileged. This information is intended only for the use of the > individual or entity to whom this electronic mail transmission was sent as > indicated above. If you are not the intended recipient, any disclosure, > copying, distribution, or action taken in reliance on the contents of the > information contained in this transmission is strictly prohibited. If you > have received this transmission in error, please delete the message. Thank > you > > > > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] -- p niemandt <[EMAIL PROTECTED]> - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
RE: Can't connect to X11 window server using '0:0' as the value ofthe display and now java.awt.HeadlessException
Hi, Another common (Java) solution is to install PJA Toolkit: PJA (Pure Java AWT) Toolkit is a JavaTM library for drawing graphics developed by eTeks. It is 100% Pure Java and doesn't use any native graphics resource of the system on which the Java Virtual Machine runs. java.awt.Graphics methods such as drawLine (), fillOval (), drawString (),... are implemented in the default JVM with native graphical functions (except in some cases for Java2D) : That means that drawLine () finally calls a GDI system function on Windows or X11 function on a X11/UNIX machine even if the drawing is done in an off-screen image using the class java.awt.Image. This ensures the best performance for drawing graphics with Java. But in a few cases, this default behavior can cause problems that PJA library improves : When no X11 Display is available on a UNIX machine (also called headless environment) or when GDI resources are low on Windows, it is impossible to compute off-screen images with java.awt.Graphics methods under a JDK version < 1.4, even if your program doesn't need to display these images. Typically, this situation happens for servlets returning dynamically generated images like pies, charts or web counters. With PJA, you don't need to change your Java programs that you expected to run : setting java.awt system property to com.eteks.awt.PJAToolkit is the only required modification to your program with Java 1.1 (see PJA FAQ and com.eteks.awt.PJAToolkit class documentation for more information). It is also impossible to compute off-screen images when the Java security manager forbids access to any Toolkit or the AWT library. In that case you can although create an instance of com.eteks.awt.PJAImage class which extends java.awt.Image, and draw into it with graphics methods. Drawing with native function doesn't give always the exact same results for each pixel on all platforms. For example, SansSerif font renders differently on MacOS, Windows and other systems : each letter of this font isn't drawn the same, and is different if font anti-aliasing is set or not on the system. On MacOS, circles aren't rendered as specified in Java documentation : fillArc () and drawArc () don't use the same base ellipse... Finally, PJA library available under GNU General Public License is supplied with its Java source files, and is a good exemple for studying : How pixels are drawn by graphics functions on a computer (com.eteks.awt.PJAGraphics uses Bresenham algorithms to draw lines and circles). How to use the Java paradigm for managing images specified by the ImageConsumer/ImageProducer/ImageObserver interfaces. How Java Toolkit works and what it needs to work (which abstract classes and interfaces to implement). Regards, Chris. -Original Message- From: p niemandt [mailto:[EMAIL PROTECTED] Sent: Friday, 21 March 2003 7:18 a.m. To: Tomcat Users List Subject: Re: Can't connect to X11 window server using '0:0' as the value ofthe display and now java.awt.HeadlessException ok: there is another solution to the headless thing: (I wrote a graphical servlet that runs on a linux box without X, and had the same problems: The headless seemed to work, well, kinda, but not to my liking): So I went the xvfb route: This is a virtual frame buffer to can install on a linux box that emulates an X session, which then kinda solves all the graphical problems in one step. You set the xvfb to the resolution required and just start and forget about it. Worth I shot, I'd say, and might safe you hours of frustration [It did me ;-) ]. On Thu, 2003-03-20 at 18:34, Micael wrote: > You using Linux? What is your environment? Anyway, setting the JVM is the > way to go if you are using Linux. > > At 06:09 PM 3/20/03 +0100, you wrote: > >Hi, > > > >I put System.setProperty("java.awt.headless", "true"); > >in my servlet init method it's ok, but now when I open a Frame, > >I get the exception HeadlessException: > > > >java.awt.HeadlessException > >at > > java.awt.GraphicsEnvironnement.checkHeadless(GraphicsEnvironement.java:121) > >at java.awt.window.(Window.java:226) > >at java.awt.Frame.(Frame.java:398) > >... > > > >What can I do? > > > >Georges > > > > > > > >Chad Johnson wrote: > > > >>If I had to wager a guess you'll need to run tomcat in a 'headless' JVM. > >>To do that add : > >> > >>-Djava.awt.headless=true > >> > >>To the : > >> > >>CATALINA_OPTS > >> > >>environment variable. > >> > >>-Chad Johnson > >> > >>-Original Message- > >>From: Georges Roux [mailto:[EMAIL PROTECTED] Sent: Tuesday, > >>March 18, 2003 5:32 PM > >>To: [EMAIL PR
Re: Can't connect to X11 window server using '0:0' as the value ofthe display and now java.awt.HeadlessException
Difficult to say: What kind of problems? I start mine using Xvfb :0 -screen 0 1600x1200x32 & {I just added it to rc.local } On Thu, 2003-03-20 at 19:27, Glenn Parsons wrote: > At 07:18 PM 3/20/2003 +, you wrote: > >ok: there is another solution to the headless thing: (I wrote a > >graphical servlet that runs on a linux box without X, and had the same > >problems: The headless seemed to work, well, kinda, but not to my > >liking): So I went the xvfb route: This is a virtual frame buffer to can > >install on a linux box that emulates an X session, which then kinda > >solves all the graphical problems in one step. You set the xvfb to the > >resolution required and just start and forget about it. > > > >Worth I shot, I'd say, and might safe you hours of frustration [It did > >me ;-) ]. > > > I had tried xvfb and had some difficulties. Any pointers? suggestions? > > Thanks, > Glenn > > > > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] -- p niemandt <[EMAIL PROTECTED]> - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Can't connect to X11 window server using '0:0' as the value ofthe display and now java.awt.HeadlessException
ok: there is another solution to the headless thing: (I wrote a graphical servlet that runs on a linux box without X, and had the same problems: The headless seemed to work, well, kinda, but not to my liking): So I went the xvfb route: This is a virtual frame buffer to can install on a linux box that emulates an X session, which then kinda solves all the graphical problems in one step. You set the xvfb to the resolution required and just start and forget about it. Worth I shot, I'd say, and might safe you hours of frustration [It did me ;-) ]. On Thu, 2003-03-20 at 18:34, Micael wrote: > You using Linux? What is your environment? Anyway, setting the JVM is the > way to go if you are using Linux. > > At 06:09 PM 3/20/03 +0100, you wrote: > >Hi, > > > >I put System.setProperty("java.awt.headless", "true"); > >in my servlet init method it's ok, but now when I open a Frame, > >I get the exception HeadlessException: > > > >java.awt.HeadlessException > >at > > java.awt.GraphicsEnvironnement.checkHeadless(GraphicsEnvironement.java:121) > >at java.awt.window.(Window.java:226) > >at java.awt.Frame.(Frame.java:398) > >... > > > >What can I do? > > > >Georges > > > > > > > >Chad Johnson wrote: > > > >>If I had to wager a guess you'll need to run tomcat in a 'headless' JVM. > >>To do that add : > >> > >>-Djava.awt.headless=true > >> > >>To the : > >> > >>CATALINA_OPTS > >> > >>environment variable. > >> > >>-Chad Johnson > >> > >>-Original Message- > >>From: Georges Roux [mailto:[EMAIL PROTECTED] Sent: Tuesday, > >>March 18, 2003 5:32 PM > >>To: [EMAIL PROTECTED] > >>Subject: Can't connect to X11 window server using '0:0' as the value of > >>the display > >> > >> > >>Hello everybody, > >> > >>Hi run Tomcat 4.1.18 Standalone on Linux debian(sid)and use > >>J2sdk1.4.1_01. > >> > >>I have a servlet which manipulate exif informations in jpg images. it > >>works well but when I try to run it on tomcat it fails (error 500) > >> > >>I have the following error: > >>"Can't connect to X11 window server using '0:0' as the value of the > >>display" > >> > >>What can I do? > >> > >>Georges > >> > >> > >>- > >>To unsubscribe, e-mail: [EMAIL PROTECTED] > >>For additional commands, e-mail: [EMAIL PROTECTED] > >> > >> > >> > >> > >>- > >>To unsubscribe, e-mail: [EMAIL PROTECTED] > >>For additional commands, e-mail: [EMAIL PROTECTED] > >> > >> > > > >-- > > > >18:54 18:54 connard > >18:55 18:54 t'as que ca a faire? ;) > >18:56 18:55 je m'ennuies ferme ouais ! encore 5mn avant la fin du taf, > > donc j'en profite pour passer dans les fortunes :) > > > > > >+==+ > >| | > >| Georges Roux| > >| URL : georgesroux.pacageek.org | > >| email : [EMAIL PROTECTED]| > >| mobile : +33 (0) 613977573 | > >+==+ > > > > > > > >- > >To unsubscribe, e-mail: [EMAIL PROTECTED] > >For additional commands, e-mail: [EMAIL PROTECTED] > > > > > > LEGAL NOTICE > > This electronic mail transmission and any accompanying documents contain > information belonging to the sender which may be confidential and legally > privileged. This information is intended only for the use of the > individual or entity to whom this electronic mail transmission was sent as > indicated above. If you are not the intended recipient, any disclosure, > copying, distribution, or action taken in reliance on the contents of the > information contained in this transmission is strictly prohibited. If you > have received this transmission in error, please delete the message. Thank > you > > > > - > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] -- p niemandt <[EMAIL PROTECTED]> - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
Re: Can't connect to X11 window server using '0:0' as the value ofthe display and now java.awt.HeadlessException
Hi, I put System.setProperty("java.awt.headless", "true"); in my servlet init method it's ok, but now when I open a Frame, I get the exception HeadlessException: java.awt.HeadlessException at java.awt.GraphicsEnvironnement.checkHeadless(GraphicsEnvironement.java:121) at java.awt.window.(Window.java:226) at java.awt.Frame.(Frame.java:398) ... What can I do? Georges Chad Johnson wrote: If I had to wager a guess you'll need to run tomcat in a 'headless' JVM. To do that add : -Djava.awt.headless=true To the : CATALINA_OPTS environment variable. -Chad Johnson -Original Message- From: Georges Roux [mailto:[EMAIL PROTECTED] Sent: Tuesday, March 18, 2003 5:32 PM To: [EMAIL PROTECTED] Subject: Can't connect to X11 window server using '0:0' as the value of the display Hello everybody, Hi run Tomcat 4.1.18 Standalone on Linux debian(sid)and use J2sdk1.4.1_01. I have a servlet which manipulate exif informations in jpg images. it works well but when I try to run it on tomcat it fails (error 500) I have the following error: "Can't connect to X11 window server using '0:0' as the value of the display" What can I do? Georges - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED] -- 18:54 18:54 connard 18:55 18:54 t'as que ca a faire? ;) 18:56 18:55 je m'ennuies ferme ouais ! encore 5mn avant la fin du taf, donc j'en profite pour passer dans les fortunes :) +==+ | | | Georges Roux| | URL : georgesroux.pacageek.org | | email : [EMAIL PROTECTED]| | mobile : +33 (0) 613977573 | +==+ - To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]