Because of the requirement of a supplier, I had to produce a datamatrix inside a document (a paying-in slip) which needed to be of a specific size and shape. I had no problems with the shape, but I could not set the size limits.
The newer version of barcode4j (2.1.0) supports the properties I need (with the name of min and max symbol size), while the version currently boundled with jasperreports 4.0.2 does not. For now I'm able to produce what I need because I recompiled barcode4j with some modifications to allow me to print the datamatrix with the right shape and size limits and forcing the procedure to use a jasperreports jar with the modified library inside it. That was easier than haking inside the code of jasperreports given that I had to be quick and I didn't want to produce a "dirty" jrxml.
Are there any plans to support the new barcode4j and it's new properties in a future jasperreports release?