NoClassDefFoundError when trying to reference external jar files

Question

I have some 3rd party jar files that I want to reference in my tomcat web application. I added this line to catalina.properties:

shared.loader=/home/ollie/dev/java/googleapi_samples/gdata/java/lib/*.jar

but I'm still getting this error:

org.apache.jasper.JasperException: javax.servlet.ServletException: java.lang.NoClassDefFoundError: com/google/gdata/util/ServiceException
    org.apache.jasper.servlet.JspServletWrapper.handleJspException(JspServletWrapper.java:491)
    org.apache.jasper.servlet.JspServletWrapper.service(JspServletWrapper.java:401)
    org.apache.jasper.servlet.JspServlet.serviceJspFile(JspServlet.java:313)
    org.apache.jasper.servlet.JspServlet.service(JspServlet.java:260)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:717)

I verified that the com.google.gdata.util.ServiceException is in the gdata-core-1.0.jar file which is in the directory:

/home/ollie/dev/java/googleapi_samples/gdata/java/lib

I did bounce tomcat after I modified catalina.properties.

Update 1: I tried copying the gdata-core-1.0.jar file into /var/lib/tomcat6/webapp/examples/WEB-INF/lib as a test but that didn't fix the problem either.

Update 2: It actually does work when I copy the jar file directly into the WEB-INF/lib directory. There was a permissions issue that I had to resolve. But it's still not working when I use the shared.loader setting. I reconfirmed that the path is correct.

Might be permission issue. Check in which user Tomcat service is running. try chmod to grant the permission. — Madhu

BalusC BalusC · Accepted Answer · 2011-02-10T15:23:13

I'm not sure about this one, but there are two potential causes:

There's a file permission issue in path as specified in shared.loader, probably the same as you had when fiddling with /WEB-INF/lib.
You aren't editing the catalina.properties file of the Tomcat instance you think you're using. For example, if you're running Tomcat from inside Eclipse, you need to ensure that you've configured Eclipse to take over Tomcat rather than using workspace metadata (where Eclispe actually runs based on a copy of Tomcat conf files). To do this, undeploy/remove all projects, doubleclick Tomcat entry and select Use Tomcat installation in Server locations section. Then the config files in Tomcat's own /conf folder will be used. Otherwise you need to edit it in Servers project of Eclipse workspace.

NoClassDefFoundError when trying to reference external jar files

2 Answers