This post is about running the XPay client provided by SecureTrading for on-line e-commerce payment processing, but it might also be useful for anyone trying to run a java application on a Debian server, particularly if they require it to be 32-bit compatible, such as running a JRE 1.4.2, or to start-up on boot.

SecureTrading’s payment processing solution provides a Java application responsible for all the encryption and secure communication with their payment gateways, leaving the application developer only responsible for forming an XML document and transmitting it on an unsecured, local socket. I have recently completed an integration using Ruby on Rails, and things were going too smoothly; something had to be problematic!

And it was this: I was running Debian Etch on a 64-bit server, and the XPay client requires Java runtime 1.4.2, which is no longer supported by Sun and only has a 32-bit linux version (unless you’re running Intel). I thought I was stuck: SecureTrading even offered to refund me at one point. I was certain there had to be solution other than getting hold of another 32-bit box, and it was, thanks to the excellent Debian o/s.

Some boffin has packaged the libraries necessary to run 32-bit apps in the ia32-libs package, so that older 32-bit applications can run alongside up-to-date 64-bit ones. It is installed in one command:
apt-get install ia32-libs
I could then download and run the binary installer for the Java runtime environment. I could then follow the instructions to setup the client certificate in the keystore and run xpay.
/usr/local/java/j2re1.4.2_19/bin/keytool -import -alias xpay -file /var/whereever/xpay/securetradingxpay.cer \
-keystore /usr/local/java/j2re1.4.2_19/lib/security/cacerts
This leaves the task of having XPay run at startup, as an init.d script. Typically, Java doesn’t play nice with init.d scripts, but I managed to get it running with Debian’s start-stop-daemon script. Starting from the /etc/init.d/skeleton file, I trimmed most of it away to end up with:
#! /bin/sh
# Author: Dan Garland <dan@dangarland.co.uk>
# Do NOT “set -e”
# PATH should only include /usr/* if it runs after the mountnfs.sh script
JAVA_HOME=/usr/local/java/j2re1.4.2_19
CLASSPATH=/var/whereever/xpay/XPay.jar
PATH=$JAVA_HOME/bin:/sbin:/usr/sbin:/bin:/usr/bin
DESC=”Xpay Client”
NAME=XPay
DAEMON=$JAVA_HOME/bin/java
DAEMON_ARGS=”-classpath $CLASSPATH -Djava.security.manager -Djava.security.policy=/var/whereever/xpay/xpaypolicy XPay ”
PIDFILE=/var/run/$NAME.pid
SCRIPTNAME=/etc/init.d/$NAME

# Read configuration variable file if it is present
&& . /etc/default/$NAME

# Load the VERBOSE setting and other rcS variables
. /lib/init/vars.sh

# Define LSB log_* functions.
# Depend on lsb-base (>= 3.0-6) to ensure that this file is present.
. /lib/lsb/init-functions

#
# Function that starts the daemon/service
#
do_start()
{
  start-stop-daemon –start –background -p $PIDFILE -m –exec $DAEMON — $DAEMON_ARGS
  echo “$NAME started…”
}

#
# Function that stops the daemon/service
#
do_stop()
{
  start-stop-daemon –stop -p $PIDFILE
  echo “$NAME stopped…”
}

#
# Function that sends a SIGHUP to the daemon/service
#
do_reload() {
        #
        # If the daemon can reload its configuration without
        # restarting (for example, when it is sent a SIGHUP),
        # then implement that here.
        #
        start-stop-daemon –stop –signal 1 –quiet –pidfile $PIDFILE –name $NAME
        return 0
}

case “$1″ in
  start)
        && log_daemon_msg “Starting $DESC” “$NAME”
        do_start
        case “$?” in
                0|1) && log_end_msg 0 ;;
                2) && log_end_msg 1 ;;
        esac
        ;;
  stop)
        && log_daemon_msg “Stopping $DESC” “$NAME”
        do_stop
        case “$?” in
                0|1) && log_end_msg 0 ;;
                2) && log_end_msg 1 ;;
        esac
        ;;
  #reload|force-reload)
        #
        # If do_reload() is not implemented then leave this commented out
        # and leave ‘force-reload’ as an alias for ‘restart’.
        #
        #log_daemon_msg “Reloading $DESC” “$NAME”
        #do_reload
        #log_end_msg $?
        #;;
  restart|force-reload)
        #
        # If the “reload” option is implemented then remove the
        # ‘force-reload’ alias
        #
        log_daemon_msg “Restarting $DESC” “$NAME”
        do_stop
        case “$?” in
          0|1)
                do_start
                case “$?” in
                        0) log_end_msg 0 ;;
                        1) log_end_msg 1 ;; # Old process is still running
                        *) log_end_msg 1 ;; # Failed to start
                esac
                ;;
          *)
                # Failed to stop
                log_end_msg 1
                ;;
        esac
        ;;
  *)
        #echo “Usage: $SCRIPTNAME {start|stop|restart|reload|force-reload}” >&2
        echo “Usage: $SCRIPTNAME {start|stop|restart|force-reload}” >&2
        exit 3
        ;;
esac

:
This script then runs XPay on boot. Make sure that the paths to the jar and the policy files are correct, and that the policy file has the correct path to the Java 1.4.2 installation directory.