I recently researched barcode solutions for my project. I could not use barbecue because I needed it to run under JRE 1.4 and the iReport classes that render barbecue required JRE 1.5.
Products I tried (free and licensed) were:
JBars, a free (MPL licensed) java barcode generation tool.
http://jbars.sourceforge.net/
This ran locally on my PC well, but deployed to OAS it ran very slow. Trial and error showed that performance was dependent upon the JRE it ran under. The speed was seconds under JRE 1.5 and minutes running under JRE 1.4.
Barcode for Java is a barcode Java SDK to be used in J2EE, J2SE environment and Java Reporting (JasperReports).
http://www.barcodelib.com
This commercial product runs works very well on all platforms I have tried on. It has JasperReports support and runs under JRE 1.4.2 and later versions. This is the Singapore based company. Not open source. Requires license.
IDAutomation Java Barcode Package
http://www.idautomation.com/java/
All I was able to reproduce was a solid black rectangle where I wanted barcodes. I wrote a paragraph to their tech support explaining what I was trying to accomplish. The response I got back was: "Thanks for your interest in our products. Unfortunately, we do not support JasperReports". Not open source. Requires license.
J4L RBarcode. http://java4less.com/barcodes/barcodes.php
They have JasperReports support, and I could get to work somewhat. Had many issues with clipping, getting barcode to show in correct frame, stretching, and having text of code show under barcode. Did not work great out of the box like the barcodelib.com product. Not open source. Requires license.
In the end, I found a workaround to run my OC4J container under Oracle App Server in a new JDK and am using barbecue with JRE 1.6.