Tomcat 5.5; 503 error; Image processing; Apache 2.2; Fedora Core 5.

elprawn · 09-22-2008, 03:26 PM

Hello.

I have a Java Class with the following code...

Code:

import java.awt.image.BufferedImage;
import javax.imageio.*;
import java.io.File;
import java.awt.Color;

public class ProduceVerifyImage {
	
	public static String getVerifyURI (String form, String code) {
		
		if (form != null && code != null && form.length() > 1 && code.length() == 4) {
			
			code = code.toLowerCase();
			BufferedImage b = new BufferedImage(120, 30, BufferedImage.TYPE_4BYTE_ABGR);
			BufferedImage[] chars = new BufferedImage[4];
			BufferedImage[] masks = new BufferedImage[4];
			BufferedImage[] mixed = new BufferedImage[4];
			
			for (int i=0; i < 4; i++) {
			
				try {
					chars[i] = ImageIO.read(new File("/var/www/dynamic/pics/site/verify/" + code.charAt(i) + ".gif"));
					masks[i] = ImageIO.read(new File("/var/www/dynamic/pics/site/verify/mask" + (int)Math.ceil(Math.random() * 40) + ".gif"));
					mixed[i] = new BufferedImage(30, 30, BufferedImage.TYPE_4BYTE_ABGR);
				} catch (Exception e) {
					
				}
				
			}
			
			for (int h = 0; h < 4; h++) {
			
				for (int i = 0; i < 30; i++ ) {
				
					for (int j = 0; j < 30; j++) {
					
						Color charscolor = new Color(chars[h].getRGB(i, j));
						Color maskscolor = new Color(masks[h].getRGB(i, j));
					
						int red = (int)((charscolor.getRed() + maskscolor.getRed()) / 2);
						int green = (int)((charscolor.getGreen() + maskscolor.getGreen()) / 2);
						int blue = (int)((charscolor.getBlue() + maskscolor.getBlue()) / 2);
					
						Color mixedcolor = new Color(red, green, blue);
					
						mixed[h].setRGB(i, j, mixedcolor.getRGB());
					}
				
				}
			
			}
			
			b.setRGB(0, 0, 30, 30, mixed[0].getRGB(0, 0, 30, 30, null, 0, 30), 0, 30);
			b.setRGB(30, 0, 30, 30, mixed[1].getRGB(0, 0, 30, 30, null, 0, 30), 0, 30);
			b.setRGB(60, 0, 30, 30, mixed[2].getRGB(0, 0, 30, 30, null, 0, 30), 0, 30);
			b.setRGB(90, 0, 30, 30, mixed[3].getRGB(0, 0, 30, 30, null, 0, 30), 0, 30);
			
			File outputfile = new File("/var/www/dynamic/pics/site/verify/codes/" + form + "-" + code + ".png");
			
			try {
				outputfile.delete();
				ImageIO.write(b, "png", outputfile);
				
			} catch (Exception e) {
				
			}
			
			return "/var/www/dynamic/pics/site/verify/codes/" + form + "-" + code + ".png";
		
		}
		
		return "";
		
	}
	
}

The function getVerifyURI is called by my servlet as follows...

Code:

String imguri = ProduceVerifyImage.getVerifyURI("Register", verifyCode);

The error I get is shown as...

Code:

Service Temporarily Unavailable

The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.

Apache/2.2.2 (Fedora) Server at 192.168.2.91 Port 80

Commenting the line out of my servlet stops the error, but I'd like to get it working. I've tried adding a main(String[] args) function to the ProduceVerifyImage class that calls the getVerifyURI function and it works as expected but the servlet throws up that 503 error when I include a call to it in my servlet code.

Thanks for your help.

elprawn · 09-23-2008, 02:59 AM

OK, well I managed to find the code which causes the error. I get the error if I leave in either of the following two lines...

Code:

chars[i] = ImageIO.read(new File("/var/www/dynamic/pics/site/verify/" + code.charAt(i) + ".gif"));
masks[i] = ImageIO.read(new File("/var/www/dynamic/pics/site/verify/mask" + (int)Math.ceil(Math.random() * 40) + ".gif"));

Any ideas?

elprawn · 09-23-2008, 03:11 AM

Specifically it seems to be ImageIO.read() and ImageIO.write() that are upsetting the server. Anyone know what the problem might be?

elprawn · 09-23-2008, 05:10 AM

Turns out any calls to any ImageIO functions will cause the error. What could be causing this?

elprawn · 09-23-2008, 06:17 AM

The last thing I have in my Catalina.out file is...

Code:

(.:5000): Gtk-WARNING **: cannot open display:

elprawn · 09-23-2008, 08:03 AM

OK, so I found out that the JAVA_HOME in my tomcat5.conf points to some lame version of java. Editing it to point to the Sun version yields the following...

Code:

Starting tomcat5: /usr/bin/rebuild-jar-repository: error: Could not find jdbc-stdext Java extension for this JVM
/usr/bin/rebuild-jar-repository: error: Could not find jndi Java extension for this JVM
/usr/bin/rebuild-jar-repository: error: Some detected jars were not found for this jvm
/usr/bin/rebuild-jar-repository: error: Could not find jaas Java extension for this JVM
/usr/bin/rebuild-jar-repository: error: Some detected jars were not found for this jvm
find: warning: you have specified the -mindepth option after a non-option argument -type, but options are not positional (-mindepth affects tests specified before it as well as those specified after it).  Please specify options before other arguments.

find: warning: you have specified the -maxdepth option after a non-option argument -type, but options are not positional (-maxdepth affects tests specified before it as well as those specified after it).  Please specify options before other arguments.

Using CATALINA_BASE:   /usr/share/tomcat5
Using CATALINA_HOME:   /usr/share/tomcat5
Using CATALINA_TMPDIR: /usr/share/tomcat5/temp
Using JRE_HOME:
                                                           [  OK  ]

Which basically translates as jndi.jar and jaas.jar not being in my $JAVA_HOME/jre/lib folder (the sun version).

Is there a painless way of fixing this?

elprawn · 09-23-2008, 11:51 AM

Right, well I finally got it seeing those jar files and made my JAVA_HOME one which was outside the /root folder and... it works!!!

Hope this has helped someone

jnojr · 06-25-2009, 01:35 PM

How did you get it to "see" those jars?

I'm using RHEL5.2 and I installed java 1.6.0u13 This error cropped up, but the only jndi.jar and jaas.jar I se are the ones that ship with the awful gcj-java-1.4.2 packages. Where do the current, modern, Sun JARs come from?

elprawn · 06-26-2009, 04:58 AM

To be honest, I can't remember. Sorry I haven't been much help. Try this, though...

Extract the folders from the sun jar files and copy them or symbolic link them into the tomcat5/common/classes, tomcat5/server/classes and tomcat5/shared/classes folders. I'm not sure which one they're meant to be in, but it'll be one of them and I'm pretty sure this should fix your problem.