java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/catalina/loader/WebappClassLoader)

Question

Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[/projectname]]

Caused by: java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/catalina/loader/WebappClassLoader) previously initiated loading for a different type with name "javax/servlet/ServletContext"

org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost]]

In print stack trace it is not giving any ClassNotFoundException :HttpServletRequest also.

I have added tomcat maven plug-in in pom.xml file. I want to run some Integration Tests, so I added plug-in to run before integration starts. Here is my plug-in

<plugin>
    <groupId>org.apache.tomcat.maven</groupId>
    <artifactId>tomcat7-maven-plugin</artifactId>
    <version>2.2</version>
    <configuration>
        <port>8989</port>
        <systemProperties>
            <archaius.deployment.environment>test</archaius.deployment.environment>
        </systemProperties>
        <path>/${project.name}</path>
    </configuration>
    <executions>
        <execution>
            <id>tomcat-run</id>
            <goals>
                <goal>run</goal>
            </goals>
            <phase>pre-integration-test</phase>
            <configuration>
                <systemProperties>
                    <!-- We want test configuration for running integration tests. -->
                    <archaius.deployment.environment>test</archaius.deployment.environment>
                    <logback-lib.env>filesystem</logback-lib.env>
                </systemProperties>
                <fork>true</fork>
            </configuration>
        </execution>
        <execution>
            <id>tomcat-shutdown</id>
            <goals>
                <goal>shutdown</goal>
            </goals>
            <phase>post-integration-test</phase>
        </execution>
    </executions>
</plugin>

this plug-in I added in pom.xml file.

I also added servlet dependency and provided scope as provided only.

<dependency>
    <groupId>javax.servlet</groupId>
    <artifactId>javax.servlet-api</artifactId>
    <version>3.1.0</version>
    <scope>provided</scope>
</dependency>

When I do mvn clean install its giving following exception

SEVERE: A child container failed during start java.util.concurrent.ExecutionException: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[/projectpath]] 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:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) Caused by: org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Tomcat].StandardHost[localhost].StandardContext[/projectpath]] at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154) ... 6 more Caused by: java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/catalina/loader/WebappClassLoader) previously initiated loading for a different type with name "javax/servlet/ServletContext" at java.lang.ClassLoader.defineClass1(Native Method) at java.lang.ClassLoader.defineClass(ClassLoader.java:763) at java.security.SecureClassLoader.defineClass(SecureClassLoader.java:142) at java.net.URLClassLoader.defineClass(URLClassLoader.java:467) at java.net.URLClassLoader.access$100(URLClassLoader.java:73) at java.net.URLClassLoader$1.run(URLClassLoader.java:368) at java.net.URLClassLoader$1.run(URLClassLoader.java:362) at java.security.AccessController.doPrivileged(Native Method) at java.net.URLClassLoader.findClass(URLClassLoader.java:361) at org.apache.catalina.loader.WebappClassLoader.findClass(WebappClassLoader.java:1191) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1669) at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1547) at java.lang.Class.getDeclaredMethods0(Native Method) at java.lang.Class.privateGetDeclaredMethods(Class.java:2701) at java.lang.Class.getDeclaredMethods(Class.java:1975) at org.apache.catalina.util.Introspection.getDeclaredMethods(Introspection.java:127) at org.apache.catalina.startup.WebAnnotationSet.loadMethodsAnnotation(WebAnnotationSet.java:281) at org.apache.catalina.startup.WebAnnotationSet.loadApplicationFilterAnnotations(WebAnnotationSet.java:113) at org.apache.catalina.startup.WebAnnotationSet.loadApplicationAnnotations(WebAnnotationSet.java:66) at org.apache.catalina.startup.ContextConfig.applicationAnnotationsConfig(ContextConfig.java:405) at org.apache.catalina.startup.ContextConfig.configureStart(ContextConfig.java:881) 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

Sep 28, 2016 12:29:26 PM org.apache.catalina.core.ContainerBase startInternal SEVERE: 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:134) at org.apache.maven.lifecycle.internal.MojoExecutor.execute(MojoExecutor.java:207) 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:128) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:307) at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:193) at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:106) at org.apache.maven.cli.MavenCli.execute(MavenCli.java:863) at org.apache.maven.cli.MavenCli.doMain(MavenCli.java:288) at org.apache.maven.cli.MavenCli.main(MavenCli.java:199) 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:1142) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617) at java.lang.Thread.run(Thread.java:745) 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

Possible duplicate of java.lang.ClassNotFoundException: HttpServletRequest — amdev
But there is no java.lang.ClassNotFoundException: HttpServletRequest in stack trace, I also added servlet dependency, how is it CLassNotFoundException? — Sat
For me it sound like a conflict with your servlet-api and the servlet-api provided by tomcat. What's your container tomcat 7 or 8 ? try 8 with your servlet-api 3.1 and set project facet Dynamic web module to 3.1. Or try to downgrade to 3.0.1 with tomcat 7.0.72 and facet 3.0. And the title of the duplicate question is wrong, the root cause of his problem was the same than you. I assume if you comment "tomcat7-maven-plugin" it works ? — amdev
externally I am not using any tomcat server, here I am using tomcat7 plug-In in pom.xml file. — Sat
I up you, edit your question with your environment I guess that could help. — amdev

Sat Sat · Accepted Answer · 2016-09-29T06:55:11

I solved this issue, actually javax.servlet was internally invlolved by other dependencies http-lib and commons-util.

I used

<exclusions>
    <exclusion>
         <artifactId>servlet-api</artifactId>
        <groupId>javax.servlet</groupId>
    </exclusion>
</exclusions>

In both the dependencies. Then the problem was solved

java.lang.LinkageError: loader constraint violation: loader (instance of org/apache/catalina/loader/WebappClassLoader)

1 Answers