Nice little library to do this is located at http://www.barcodelib.com/java_barcode/main.html…
import com.barcodelib.barcode.*; public class MyBarCode { public static void main (String args[]) throws Exception { Linear barcode = new Linear(); barcode.setType(Linear.UPCA); java.util.Random r = new java.util.Random(); String str = new Integer(Math.abs(r.nextInt())).toString(); StringBuilder sb = new StringBuilder(); for (int toPrepend=11-str.length(); toPrepend>0; toPrepend--) { sb.append('0'); } sb.append(str); String s = sb.toString(); System.out.println(s); barcode.setData(s); barcode.renderBarcode("c://barcode.gif"); } }