Cannot load web page when running Struts2 v6.3.0.2 - ran java.lang.NoClassDefFoundError

Question

I'm having trouble running a web application when using Struts2 v6.3.0.2. When I tried to load a page on a web browser, I received this error below.

Uncaught exception thrown by filter struts2: java.lang.NoClassDefFoundError: org.apache.struts2.RequestUtils

Please, can anyone assist?

The tools I'm using are eclipse IDE, Java 8, and WebSphere v9 as an application server. I'm using Maven for getting all the dependencies.

Here is my pom.xml below.

    <dependencies>
    <dependency>
        <groupId>org.apache.struts</groupId>
        <artifactId>struts2-core</artifactId>
        <version>6.3.0.2</version>
        <scope>compile</scope>
    </dependency>

    <dependency>
        <groupId>com.jgeppert.struts2.bootstrap</groupId>
        <artifactId>struts2-bootstrap-plugin</artifactId>
        <version>4.0.0</version>
        <scope>compile</scope>
    </dependency>
    <dependency>
        <groupId>org.apache.struts</groupId>
        <artifactId>struts2-convention-plugin</artifactId>
        <version>6.3.0.2</version>
        <scope>compile</scope>
    </dependency>
<dependency>
    <groupId>com.opencsv</groupId>
    <artifactId>opencsv</artifactId>
    <version>5.9</version>
</dependency>
<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
    <scope>provided</scope>
</dependency>
<dependency>
    <groupId>org.apache.clerezza.ext</groupId>
    <artifactId>org.json.simple</artifactId>
    <version>0.4</version>
</dependency>
</dependencies>  
  <build>
    <sourceDirectory>src</sourceDirectory>
    <resources>
      <resource>
        <directory>resources</directory>
        <excludes>
          <exclude>**/*.java</exclude>
        </excludes>
      </resource>
    </resources>
    <plugins>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-compiler-plugin</artifactId>
        <version>3.8.1</version>
        <configuration>
          <source>1.8</source>
          <target>1.8</target>
        </configuration>
      </plugin>
      <plugin>
        <artifactId>maven-war-plugin</artifactId>
        <version>3.2.3</version>
        <configuration>
          <warSourceDirectory>WebContent</warSourceDirectory>
        </configuration>
      </plugin>
    </plugins>
  </build>

Also here is my web.xml below.

<?xml version="1.0" encoding="UTF-8"?>
<web-app xmlns="http://xmlns.jcp.org/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/javaee http://xmlns.jcp.org/xml/ns/javaee/web-app_3_1.xsd" version="3.1">
    <display-name>mysite</display-name>
     <welcome-file-list>
        <welcome-file>index.jsp</welcome-file>
    </welcome-file-list> 
    
     <filter>
        <filter-name>struts2</filter-name>
        <filter-class>
            org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter
        </filter-class>
    </filter>
    
      <filter-mapping>
        <filter-name>struts2</filter-name>
        <url-pattern>/*</url-pattern>
        <!-- <url-pattern>results.jsp</url-pattern> -->
    </filter-mapping>
</web-app>

When I changed the Struts2 version to 2.5.33 and Struts2-convention-plugin to 2.5.33 in the pom.xml, it works and I see my index.jsp page. It doesn't work when I use the current version of struts2. I tried Maven Clean, Project Clean, rebuild the project, remove target folder contents, view that struts2 is in the buildpath, and verified that the class 'org.apache.struts2.RequestUtils' existed in struts2 package and I still received the error. I tried debugging the class 'StrutsPrepareAndExecuteFilter' when loading my index.jsp, and when it reaches to run a class 'org.apache.struts2.RequestUtils', it throws and error. Error from console log below:

000000c9 filter        E com.ibm.ws.webcontainer.filter.FilterInstanceWrapper doFilter SRVE8109W: Uncaught exception thrown by filter struts2: java.lang.NoClassDefFoundError: org.apache.struts2.RequestUtils (initialization failure)
at java.lang.J9VMInternals.initializationAlreadyFailed(J9VMInternals.java:91)
at org.apache.struts2.dispatcher.filter.StrutsPrepareAndExecuteFilter.doFilter(StrutsPrepareAndExecuteFilter.java:123)
at com.ibm.ws.webcontainer.filter.FilterInstanceWrapper.doFilter(FilterInstanceWrapper.java:197)
at com.ibm.ws.webcontainer.filter.WebAppFilterChain.doFilter(WebAppFilterChain.java:90)
at com.ibm.ws.webcontainer.filter.WebAppFilterManager.doFilter(WebAppFilterManager.java:969)
at com.ibm.ws.webcontainer.filter.WebAppFilterManager.invokeFilters(WebAppFilterManager.java:1109)
at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:4112)
at com.ibm.ws.webcontainer.webapp.WebAppImpl.handleRequest(WebAppImpl.java:2171)
at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:304)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:1028)
at com.ibm.ws.webcontainer.WSWebContainer.handleRequest(WSWebContainer.java:1817)
at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:294)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:465)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewRequest(HttpInboundLink.java:532)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.processRequest(HttpInboundLink.java:318)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.ready(HttpInboundLink.java:289)
at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.sendToDiscriminators(NewConnectionInitialReadCallback.java:214)
at com.ibm.ws.tcp.channel.impl.NewConnectionInitialReadCallback.complete(NewConnectionInitialReadCallback.java:113)
at com.ibm.ws.tcp.channel.impl.AioReadCompletionListener.futureCompleted(AioReadCompletionListener.java:175)
at com.ibm.io.async.AbstractAsyncFuture.invokeCallback(AbstractAsyncFuture.java:217)
at com.ibm.io.async.AsyncChannelFuture.fireCompletionActions(AsyncChannelFuture.java:161)
at com.ibm.io.async.AsyncFuture.completed(AsyncFuture.java:138)
at com.ibm.io.async.ResultHandler.complete(ResultHandler.java:204)
at com.ibm.io.async.ResultHandler.runEventProcessingLoop(ResultHandler.java:775)
at com.ibm.io.async.ResultHandler$2.run(ResultHandler.java:905)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1892)

My goal is to upgrade my application to run struts2 latest version. Please insist? let me know if you need more details.

Answer 1

Going from 2.5x to 6x requires some tweaks to your application... Take a look at the migration guide for more info. https://cwiki.apache.org/confluence/display/WW/Struts+2.5+to+6.0.0+migration