You cannot print barcode directly. What you can do it to develop a small application to retrieve barcode from backend database and then print it with the help of application you develop.

Java Barcode Generator(www.keepautomation.com/products/java_barcode/) compatible with 1.4.0 and above version can succeeded in generating and printing barcode images with Code 39, Code 128, Code 2 of 5, QR Code, Data Matrix, etc. no extra extension to print the barcodes you need.

I have ever been running in to the same problems as you, and I chose to use a specific printer to print barcode labels and still have problems on altering the intensity. I have kept trying to find the settings for it but to no avail. Could someone please explain exactly where the settings are?

I am using this Java QR Code barcode genrator SDK (www.onbarcode.com/.../qrcode.html). It provides detailed settings in the tutorial of creating barcode in Java (www.onbarcode.com/.../java-barcode-generation.html). You may take a look at the tutorial of your barcode generator.

Image Barcode creating and scanning in ASP .NET, C# .NET, VB .NET, you can created any common linear and 2d barcode type by using the barcode add on applicatin.
www.rasteredge.com/.../

I prefer to 1D & 2D barcode SDK with specific tutorial for barcode generation because I am a beginner (like one offered by www.barcodelib.com/.../barcode_symbologies.html)

I use a barcode generator driver found on the internet . Install it and it becomes a selectable option.Then you can generate barcodes in many formats in any program at all, including Adobe Acrobat . Just open the sdk, select barcode, and choice a form you want, then you can generate barcode in c#, vb, asp ,etc ,the task will be finished in several seconds. if you haven't found a good choice , you can have a try. best wishes.
www.rasteredge.com/.../

As there are so many barcode symbologies, have you chosen a target barcode? I have ever used a barcode generation control that supports most common linear and 2D barcodes, including Data Matrix, QR Code, Code 39, etc. And I have referred to this Code 39 barcode generation tutorial:
www.rasteredge.com/.../

You can follow these steps to create and print Barcodes label using JDK 4.0.
1:Install Java with JDK 4.0 and make sure the Java executables are included in the search path.
2:Download the Java Barcode Generation Package such as(www.keepautomation.com/.../...rcode_generator.html) for the purpose type with linear, QR Code, PDF 417 or Data Matrix and extract the file.
3:Copy .jar file in the Java Barcode Generation package into the Java class path and the barcode library is enabled here for Java development.
4:Then the Java Barcode Generator is installed and you can create and print Barcodes label using JDK 4.0 with it.