App Engine java.lang.NoClassDefFoundError: com/google/api/server/spi/guice/GuiceSystemServiceServletModule

Question

I wanted to change some small things to my App engine backend but I could not upload it anymore to the Appengine Google Cloud. So I updated the version of the appengine sdk to version 1.9.21 (like in another project which still updates).

Now I get the following error while running the project:

java.lang.NoClassDefFoundError: com/google/api/server/spi/guice/GuiceSystemServiceServletModule

When I deploy it I allways get this error:

java.lang.NoClassDefFoundError: nl/mynamespace/guice/FDGuiceSystemServiceServletModule

This class should be included in com.google.appengine:appengine-endpoints:1.9.22 What can be wrong?

The strange thing is that I changed nothing on the Guice part and in another project it is working the same way...

FDGuiceServletContextListener.java:

public class FDGuiceServletContextListener extends GuiceServletContextListener {

    @Override
    protected Injector getInjector() {
        return Guice.createInjector(new     FDGuiceSystemServiceServletModule());
    }
}

FDGuiceSystemServiceServletModule.java

public class FDGuiceSystemServiceServletModule extends GuiceSystemServiceServletModule {

    @Override
    protected void configureServlets() {
        super.configureServlets();

        Set<Class<?>> serviceClasses = new HashSet<>();
        serviceClasses.add(DashboardApi.class);
        serviceClasses.add(SalesAPI.class);
        serviceClasses.add(LeadsApi.class);

        serveGuiceSystemServiceServlet("/_ah/spi/*", serviceClasses);
    }
}

web.xml

[..] <filter> <filter-name>guiceFilter</filter-name> <filter-class>com.google.inject.servlet.GuiceFilter</filter-class> </filter> <filter-mapping> <filter-name>guiceFilter</filter-name> <url-pattern>/_ah/spi/*</url-pattern> <url-pattern>/*</url-pattern> </filter-mapping> <listener> <listener-class>nl.mynamespace.guice.FDGuiceServletContextListener</listener-class> </listener> [..]

Roel Roel · Accepted Answer · 2016-06-10T12:06:19

Sorry i'm new to the build system of Intellj / Maven. I had to delete the libs from Project Structure --> Artifacts --> Output Layout --> WEB-INF\lib and add them again.

I'm used to Gradle and Android development where I only have to change gradle file.

I still don't understand why this has to be configured at 2 places but now I will never forget this.

App Engine java.lang.NoClassDefFoundError: com/google/api/server/spi/guice/GuiceSystemServiceServletModule

1 Answers