No Spring WebApplicationInitializer types detected on classpath

Question

My Eclipse project is suddenly no longer deploying properly. I can\'t trace it to any particular change I\'ve made to the environment.

I have tested with multiple s

Answer 1

Watch out if you are using Maven. Your folder's structure must be right.

When using Maven, the WEB-INF directory must be inside webapp:

src/main/webapp/WEB-INF

Answer 2

In my case it also turned into a multi-hour debugging session. Trying to set up a more verbose logging turned out to be completely futile because the problem was that my application did not even start. Here's my context.xml:

<?xml version='1.0' encoding='utf-8'?>
<Context path="/rc2" docBase="rc2" antiResourceLocking="false" >
    <JarScanner>
        <JarScanFilter
            tldScan="spring-webmvc*.jar, spring-security-taglibs*.jar, jakarta.servlet.jsp.jstl*.jar"
            tldSkip="*.jar"
            <!-- my-own-app*.jar on the following line was missing! -->
            pluggabilityScan="${tomcat.util.scan.StandardJarScanFilter.jarsToScan}, my-own-app*.jar"
            pluggabilitySkip="*.jar"/>
    </JarScanner>
</Context>

The problem was that to speed up the application startup, I started skipping scanning of many JARs, unfortunately including my own application.

Answer 3

I spent hours on this, and the solution was:

• Stop Tomcat
• "Project" menu -> Clean -> Clean all projects
• Servers tab -> Tomcat -> Right click -> Clean...
• Right click on project -> Run as -> Run on server

Answer 4

WebApplicationInitializer is an interface you can implement in one of your classes. At startup Spring is scanning for this classes, as long as you are using servlet spec 3 and have a metadata-complete="false" attribute in your web.xml. But that doesn't seem to be the problem. The only error I can figure out is the missing slf4j-log4j12.jar.

Answer 5

xml was not in the WEB-INF folder, thats why i was getting this error, make sure that web.xml and xxx-servlet.xml is inside WEB_INF folder and not in the webapp folder .

Answer 6

I spent my whole day today investigating this problem and none of the answers helped. Here is my scenario. The WebApplicationInitializer types in my case are inside jar files. we have a multi-module gradle web project where each module is packaged as a jar and included in the web artifact. The problem is that Apache tomcat's classloader is not looking for the implementations of WebApplicationIntializer in WEB-INF/lib instead its looking for those types directly under WEB-INF/classes folder.

Here is what I ended up doing for anyone who faces this problem in future.

I implemented a ServletContainerInitializer myself and added that class name to META-INF/services/javax.servlet.ServletContainerInitializer

In the implementation, I copied the code from SpringServletContainerIntializer and used reflections to find the classes implementing a CustomWebApplicationInitializer interface, I did not make use of spring's WebApplicationInitializer interface to avoid any conflicts. Basically I have the same contract as WebApplicationInitializer with a different name. Now on startup, my container initializer is called and I delegated the call to all my CustomWebApplicationInitializers.

Based on my search I also found that the loader used for tomcat can be updated to have it search in WEB-INF/lib but I have little control over the tomcat I deploy my app to so went with the above solution. Hope this helps someone.