The following code illustrates how to create a Data Matrix barcode in a java.awt.Image object:
DataMatrix barcode = new DataMatrix();
barcode.setSize(400,200);
// create image
java.awt.image.BufferedImage image = new java.awt.image.BufferedImage(
barcode.getSize().width,barcode.getSize().height,
java.awt.image.BufferedImage.TYPE_BYTE_INDEXED );
// get graphic context of image
java.awt.Graphics imgGraphics = image.createGraphics();
// paint barcode in graphics context of image
barcode.paint(imgGraphics );