Images are not displayed: java.lang.NoClassDefFoundError

When you request an image from your CQ instance, the error.log contains an error similar to the following:

*ERROR* Component: Error in cqImage java.lang.NoClassDefFoundError at java.lang.Class.forName0(Native Method) at java.lang.Class.forName(Class.java:141) at java.awt.GraphicsEnvironment.getLocalGraphicsEnvironment(GraphicsEnvironment.java:62) at java.awt.image.BufferedImage.createGraphics(BufferedImage.java:1041) at com.day.image.Layer.initBaseImage(Layer.java:2862) at com.day.image.Layer.init(Layer.java:2852) at com.day.image.Layer.<init>(Layer.java:535)

Or, during instance startup you have an error in your error.log similar to the following:

08.05.2007 13:40:28 *ERROR* graphics: hasGraphics: getLocalGraphicsEnvironment throws java.lang.InternalError: Can't connect to X11 window server using ':0.0' as the value of the DISPLAY variable.

Solution

Set a special JVM parameter to tell Java that the system does not have a graphical subsystem. Add the following line in your JVM parameters:

-Djava.awt.headless=true

Additional information

These errors can occur when the server does not have a graphical subsystem (UNIX without X).