Servlet giving error java.lang.NoClassDefFoundError

java servlets classnotfound
Sangeet Menon picture Sangeet Menon · Apr 7, 2011 · Viewed 15.9k times · Source

I am using the following code in a servlet of my app

java.awt.Image awtImg = java.awt.Toolkit.getDefaultToolkit().createImage(str1);

When I run the application and call the servlet I get the following error

java.lang.NoClassDefFoundError: Could not initialize class sun.awt.X11.XToolkit
java.lang.Class.forName0(Native Method)
java.lang.Class.forName(Class.java:169)
java.awt.Toolkit$2.run(Toolkit.java:834)
java.security.AccessController.doPrivileged(Native Method)
java.awt.Toolkit.getDefaultToolkit(Toolkit.java:826)
noticeandreports.pdf.appendFiles.PdfFunctionsClass.addSealSpace(PdfFunctionsClass.java:198)
OJ.NoticesandReports.generate_151_OJNotice.execute(generate_151_OJNotice.java:768)
org.apache.struts.action.RequestProcessor.processActionPerform(RequestProcessor.java:425)
org.apache.struts.action.RequestProcessor.process(RequestProcessor.java:228)
org.apache.struts.action.ActionServlet.process(ActionServlet.java:1913)
org.apache.struts.action.ActionServlet.doPost(ActionServlet.java:462)
javax.servlet.http.HttpServlet.service(HttpServlet.java:637)
javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

I have hosted the app on a Linux machine with Java version JDK 1.6.20..

What might be causing the issue...

noticeandreports.pdf.appendFiles.PdfFunctionsClass is the class where the code is written and OJ.NoticesandReports.generate_151_OJNotice is the servlet that calls the method inside the above class...

Answer

Jon Skeet picture Jon Skeet · Apr 7, 2011

To use AWT classes in a server side application, I believe you need to run in "headless" mode. Change your servlet container's startup to include:

-Djava.awt.headless=true

(Or set the system property within your own code if you really have to.)

You might also want to consider using an alternative imaging library - either a third-party one or the javax.imageio package.

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