SEVERE: Exception springSecurityFilterChain... ClassCastException... DelegatingFilterProxy cannot be cast

Question

can anyone help me resolve my tomcat run error, I get the following error when i run tomcat:

SEVERE: Exception starting filter springSecurityFilterChain
java.lang.ClassCastException: org.springframework.web.filter.DelegatingFilterProxy cannot be cast to javax.servlet.Filter
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:275)
    at org.apache.catalina.core.ApplicationFilterConfig.setFilterDef(ApplicationFilterConfig.java:422)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:115)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4001)
    at org.apache.catalina.core.StandardContext.start(StandardContext.java:4651)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
    at org.apache.catalina.core.StandardHost.start(StandardHost.java:785)
    at org.apache.catalina.core.ContainerBase.start(ContainerBase.java:1045)
    at org.apache.catalina.core.StandardEngine.start(StandardEngine.java:445)
    at org.apache.catalina.startup.Embedded.start(Embedded.java:825)
    at org.codehaus.mojo.tomcat.AbstractRunMojo.startContainer(AbstractRunMojo.java:533)
    at org.codehaus.mojo.tomcat.AbstractRunMojo.execute(AbstractRunMojo.java:239)
    at org.apache.maven.plugin.DefaultPluginManager.executeMojo(DefaultPluginManager.java:490)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoals(DefaultLifecycleExecutor.java:694)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeStandaloneGoal(DefaultLifecycleExecutor.java:569)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoal(DefaultLifecycleExecutor.java:539)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeGoalAndHandleFailures(DefaultLifecycleExecutor.java:387)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.executeTaskSegments(DefaultLifecycleExecutor.java:348)
    at org.apache.maven.lifecycle.DefaultLifecycleExecutor.execute(DefaultLifecycleExecutor.java:180)
    at org.apache.maven.DefaultMaven.doExecute(DefaultMaven.java:328)
    at org.apache.maven.DefaultMaven.execute(DefaultMaven.java:138)
    at org.apache.maven.cli.MavenCli.main(MavenCli.java:362)
    at org.apache.maven.cli.compat.CompatibleMain.main(CompatibleMain.java:60)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39)
    at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)
    at java.lang.reflect.Method.invoke(Method.java:597)
    at org.codehaus.classworlds.Launcher.launchEnhanced(Launcher.java:315)
    at org.codehaus.classworlds.Launcher.launch(Launcher.java:255)
    at org.codehaus.classworlds.Launcher.mainWithExitCode(Launcher.java:430)
    at org.codehaus.classworlds.Launcher.main(Launcher.java:375)

Answer 1

One of your dependencies are including a servlet-api into your war file which causes that behavior. Using mvn dependency:tree, you can find out which of your dependency is that. After that you need to exclude the servlet-api as follows:

<dependency>
  <groupId>[VALUE]</groupId>
  <artifactId>[VALUE]</artifactId>
  <version>[VALUE]</version>
  <exclusions>
    <exclusion>
      <groupId>javax.servlet</groupId>
      <artifactId>servlet-api</artifactId>
    </exclusion>
  </exclusions>
</dependency>

You need to do this for other servlet-api's (e.g. org.mortbay.jetty:servlet-api, ..) as well.

Answer 2

I could fix this by removing servlet-api.jar from my deployment assembly (in eclipse)

my-web-project-> properties -> Deployment Assembly

and removing it. Others state that on maven projects the scope of the servlet-api dependency must be set to 'provided'