Cups4J Server

JEE 7 print service implementation for JBoss/Wildfly 11 (http://wildfly.org).

Features

• Web Service accepting print jobs and queries for job status
• Print job creation in database
• Signal new print jobs via JMS
• Retry print jobs that could not be printed because of recoverable errors (network connection refused etc.)
• Automatic print job maintenance (update job state in database)
• Take actions when print jobs complete (f.ex. remove from database)
• Simple Java web service client to print from command line or to be included in client apps

Get ready to run

First run Wildfly 11 with full profile. This is necessary in order to be able to use message driven beans.

set WILDFLY_HOME to {your installation directory}/wildfly-11.0.0.Final

set JAVA_HOME to your Java 8 or later installation (JDK)

Change to {your installation directory}/wildfly-11.0.0.Final/bin and run from there:

on UNIX/Linux:

  ./standalone.sh -c standalone-full.xml

or Windows:

  standalone.bat -c standalone-full.xml

Deploy the application to Wildfly

Change to cups4jserver directory and run:

mvn clean install wildfly:deploy 

Test your installation

Try to print a PDF or Postscript file run

java -jar client/target/server-client-1.0.0-SNAPSHOT.one-jar.jar

to get help on command line parameters possible.

For a quick print on localhost running Wildfly and CUPS with a Printer named "PDF" you can try to print the test pdf file this way:

java -jar client/target/server-client-1.0.0-SNAPSHOT.one-jar.jar -w localhost -h localhost -P PDF -f client/pdf.pdf

Cups4J Server will go through the following steps:

• persist the print job in database and return the primary key as jobID to the client
• send a JMS message to the print job queue to signal the existence of a new print job
• message receiver will fetch this print job from the database and print it via Cups4J on the printer "PDF". Dependent on print success the print job in the database will be updated with status spooled, error or recoverable_error.
• every 30 seconds the print job maintenance will start and check the print job database
  • check all jobs that are "spooled" and update status in database as long as job state is NOT completed
  • completed jobs are removed from database
  • try to reprint jobs with recoverable errors (connection errors while trying to print to CUPS server and similar errors)
• if the database table of print jobs is empty every printed job has completed

Conclusion

The current implementation is a quick shot that shows how a smart print server could work. There is in general no need to use JMS in a print server like this, but it can be of good use in complex situations with more wildfly servers or a dedicated print server. At least it is impressive to see how easy it is today to make use of messaging without the need to change a single configuration file or deployment descriptor.

Anyway, at this time this is demonstration code not intended to be used in production environments.