The target class does not match the specified target type

Question

I am getting the below error in logs in SDL. This is related with ADF, I am not able to find the way to sort this out.

14-Feb-2017 13:59:45.253 INFO [localhost-startStop-1] org.apache.catalina.core.ApplicationContext.log Closing Spring root WebApplicationContext
14-Feb-2017 13:59:49.156 INFO [localhost-startStop-1] org.apache.catalina.core.ApplicationContext.log Spring WebApplicationInitializers detected on classpath: [com.ceair.dxa.WebAppConfiguration@5a3a8603, com.sdl.dxa.modules.smarttarget.SmartTargetWebInitializer@7c1585b5]
14-Feb-2017 13:59:49.655 INFO [localhost-startStop-1] org.apache.catalina.core.ApplicationContext.log Initializing Spring root WebApplicationContext
14-Feb-2017 13:59:54.668 SEVERE [localhost-startStop-1] org.apache.catalina.core.StandardContext.filterStart Exception starting filter Ambient Data Framework
 java.lang.ClassCastException: The target class does not match the specified target type
    at com.tridion.util.ReflectionUtil.loadClassInstanceWithTypes(ReflectionUtil.java:81)
    at com.tridion.util.ReflectionUtil.loadClassInstance(ReflectionUtil.java:103)
    at com.tridion.ambientdata.web.RequestValidatorFactory.newRequestValidator(RequestValidatorFactory.java:27)
    at com.tridion.ambientdata.web.AmbientDataServletFilter.init(AmbientDataServletFilter.java:116)
    at org.apache.catalina.core.ApplicationFilterConfig.initFilter(ApplicationFilterConfig.java:279)
    at org.apache.catalina.core.ApplicationFilterConfig.getFilter(ApplicationFilterConfig.java:260)
    at org.apache.catalina.core.ApplicationFilterConfig.<init>(ApplicationFilterConfig.java:105)
    at org.apache.catalina.core.StandardContext.filterStart(StandardContext.java:4700)
    at org.apache.catalina.core.StandardContext.startInternal(StandardContext.java:5340)
    at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:145)
    at org.apache.catalina.core.ContainerBase.addChildInternal(ContainerBase.java:753)
    at org.apache.catalina.core.ContainerBase.addChild(ContainerBase.java:729)
    at org.apache.catalina.core.StandardHost.addChild(StandardHost.java:717)
    at org.apache.catalina.startup.HostConfig.deployWAR(HostConfig.java:940)
    at org.apache.catalina.startup.HostConfig$DeployWar.run(HostConfig.java:1816)
    at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source)
    at java.util.concurrent.FutureTask.run(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
    at java.lang.Thread.run(Unknown Source)

Answer 1

A ClassCastException happens when you try to cast objects of one type to a different type and the two aren't compatible.

I would guess that either you accidentally installed the wrong version of a JAR file, or that you have a cartridge configured that is built against an older, incompatible version of the ADF (although I don't think there's been any breaking changes so it seems unlikely). Or perhaps the cartridge itself refers to some third-party libraries that now have a newer version installed.

To find the cause, I would start by disabling all cartridges and re-enabling them one by one. If it happens without any cartridges configured, the problem is likely with your ADF installation/configuration. If it happens when a particular cartridge is used, you'll want to look into the specifics of that cartridge to find the cause.