When running Java Servlets in headless mode, errors similar to the following may be received:

java.awt.HeadlessException at java.applet.Applet.<init>

This issue was corrected in the June 2004 release of IDAutomation Java Barcode Products. If an active Priority Support and Upgrade Subscription through RegNow is in effect, please contact IDAutomation with the order ID number to receive the updated download link. If an active support agreement is in effect through the IDAutomation online store, please go back to the store and go to “My Account”. Enter the user name, which is the email address and the password that created at the time of order. Then when logging in, the invoice should appear on the screen and in the upper right hand corner. There will be a link to “My Downloads,” which is where the update can be downloaded. To reactivate the Priority Support and Upgrade Subscription, please visit: http://www.idautomation.com/extended/about.html

If this error occurs, it may be that the JDK being used does not allow instantiation of an Applet in a headless environment. While the applet is not visible in the browser when creating barcodes with the servlet, the IDAutomation Java barcode servlet uses the applet for several processing functions.

There are 4 solutions:

1. Obtain the latest product as described above.
2. Use the IDAutomation secure servlet to create the barcodes without using applet. There is a working example in the Linear Source Code.zip file, which is in the Linear Java Barcode Package. The file name is IDAutomationSecureServlet.java.
3. Obtain an update to the JDK that will allow instantiation of an applet.
4. Run the servlet on another system that does not have this problem.