Launch an application in using Tomcat Embedded with Maven

Question

I'd like to launch a web application in using an embedded tomcat instead of the standalone version. In order to do that, I've declared the tomcat maven plugin in my pom.xml. When I tried to launch that, I got this error :

Exception in thread "Thread-2" java.lang.NoClassDefFoundError: org/apache/commons/io/FileUtils
at org.apache.tomcat.maven.plugin.tomcat7.run.RunMojo$2.run(RunMojo.java:295)
Caused by: java.lang.ClassNotFoundException: org.apache.commons.io.FileUtils
at  org.codehaus.plexus.classworlds.strategy.SelfFirstStrategy.loadClass(SelfFirstStrategy.java:50)
at org.codehaus.plexus.classworlds.realm.ClassRealm.unsynchronizedLoadClass(ClassRealm.java:271)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:247)
at org.codehaus.plexus.classworlds.realm.ClassRealm.loadClass(ClassRealm.java:239)
... 1 more

This is my POM.xml's configuration :

    <build>
  <plugins>
    <plugin>
      <groupId>org.apache.tomcat.maven</groupId>
      <artifactId>tomcat7-maven-plugin</artifactId>
      <version>${tomcat-maven-plugin.version}</version>
      <configuration>
        <port>8080</port>
        <path>/ppc-v2.webapp</path>
      </configuration>
      <dependencies>
        <dependency>
          <groupId>upgrade.karavel.framework</groupId>
          <artifactId>framework.integration.camel.extension</artifactId>
          <version>${framework.camel.extension.version}</version>
          <exclusions>
            <exclusion>
              <groupId>org.apache.geronimo.specs</groupId>
              <artifactId>geronimo-servlet_2.5_spec</artifactId>
            </exclusion>
          </exclusions>
        </dependency>
        <dependency>
          <groupId>upgrade.karavel.framework</groupId>
          <artifactId>framework.frontend.web</artifactId>
          <version>${framework.frontend.web.version}</version>
          <exclusions>
            <exclusion>
              <groupId>org.springframework.webflow</groupId>
              <artifactId>spring-webflow</artifactId>
            </exclusion>
            <exclusion>
              <groupId>javax.servlet</groupId>
              <artifactId>servlet-api</artifactId>
            </exclusion>
          </exclusions>
        </dependency>
      </dependencies>
    </plugin>
  </plugins>
</build>

EDIT: I've the following stacktrace at the top of the log :

GRAVE: A child container failed during start java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[/ppc-v2.webapp]] at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:192) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:800) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[/ppc-v2.webapp]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) ... 6 more Caused by: java.lang.ClassCastException: org.springframework.web.SpringServletContainerInitializer cannot be cast to javax.servlet.ServletContainerInitializer at org.apache.catalina.startup.ContextConfig.getServletContainerInitializer(ContextConfig.java:1670) at org.apache.catalina.startup.ContextConfig.getServletContainerInitializers(ContextConfig.java:1652) at org.apache.catalina.startup.ContextConfig.processServletContainerInitializers(ContextConfig.java:1562) at org.apache.catalina.startup.ContextConfig.webConfig(ContextConfig.java:1270) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:878) at org.apache.catalina.startup.ContextConfig.lifecycleEvent(ContextConfig.java:376) at org.apache.catalina.util.LifecycleSupport.fireLifecycleEvent(LifecycleSupport.java:119) at org.apache.catalina.util.LifecycleBase.fireLifecycleEvent(LifecycleBase.java:90) at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5322) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ... 6 more sept. 03, 2018 12:34:07 PM org.apache.catalina.core.ContainerBase startInternal GRAVE: A child container failed during start java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost]] at java.util.concurrent.FutureTask.report(FutureTask.java:122) at java.util.concurrent.FutureTask.get(FutureTask.java:192) at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1123) at org.apache.catalina.core.StandardEngine.startInternal(StandardEngine.java:302) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.StandardService.startInternal(StandardService.java:443) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.core.StandardServer.startInternal(StandardServer.java:732) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) at org.apache.catalina.startup.Tomcat.start(Tomcat.java:341) at org.apache.tomcat.maven.plugin.tomcat7.run.AbstractRunMojo.startContainer(AbstractRunMojo.java:1238) at org.apache.tomcat.maven.plugin.tomcat7.run.AbstractRunMojo.execute(AbstractRunMojo.java:592) at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo(DefaultBuildPluginManager.java:132) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:208) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:153) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:145) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:116) at org.apache.maven.lifecycle.internal.LifecycleModuleBuilder.buildProject(LifecycleModuleBuilder.java:80) at org.apache.maven.lifecycle.internal.builder.singlethreaded.SingleThreadedBuilder.build(SingleThreadedBuilder.java:51) at org.apache.maven.lifecycle.internal.LifecycleStarter.execute(LifecycleStarter.java:120) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:347) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:154) at org.apache.maven.cli.MavenCli.execute(MavenCli.java:582) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:214) at org.apache.maven.cli.MavenCli.main(MavenCli.java:158) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62) at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43) at java.lang.reflect.Method.invoke(Method.java:498) at org.codehaus.plexus.classworlds.launcher.Launcher.launchEnhanced(Launcher.java:289) at org.codehaus.plexus.classworlds.launcher.Launcher.launch(Launcher.java:229) at org.codehaus.plexus.classworlds.launcher.Launcher.mainWithExitCode(Launcher.java:415) at org.codehaus.plexus.classworlds.launcher.Launcher.main(Launcher.java:356) Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1559) at org.apache.catalina.core.ContainerBase$StartChild.call(ContainerBase.java:1549) at java.util.concurrent.FutureTask.run(FutureTask.java:266) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) Caused by: org.apache.catalina.LifecycleException: A child container failed during start at org.apache.catalina.core.ContainerBase.startInternal(ContainerBase.java:1131) at org.apache.catalina.core.StandardHost.startInternal(StandardHost.java:800) at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:150) ... 6 more

Answer 1

You can include Apache commons-io jar by adding this dependency in pom.xml

<!-- https://mvnrepository.com/artifact/commons-io/commons-io -->
<dependency>
    <groupId>commons-io</groupId>
    <artifactId>commons-io</artifactId>
    <version>2.4</version>
</dependency>

If you want to add the jar file in tomcat lib all you can do is download the jar file from https://commons.apache.org/proper/commons-io/download_io.cgi and go to the location where you have installed tomcat and go to lib folder and copy paste the jar. In my case my location is

C:\Program Files\Apache Software Foundation\Tomcat 9.0\lib

You can similarly check in your local system.

Answer 2

Thanks everyone, but you couldn't resolve my problems :D I noticed I still use the jetty plugin, and one of the dependency named jetty-jndi, which include servlet-api had a conflict with the servlet-api of the embedded tomcat. For some unknown reason, i couldn't see this jar in the maven dependency:tree of Eclipse.

Thats the reason why I got this error.

Thanks all.

Best Regards