Getting Spring Error "Bean named 'x' must be of type [y], but was actually of type [$Proxy]" in Jenkins

Excerpt from question comments above:

Are you running Cobertura, Sonar or other code-instrumenting tool on Jenkins? Note that mvn site might also be configured to include Cobertura report in generated site.

The problem with Cobertura is that it performs pretty heavy byte-code instrumentation including the addition of some custom interfaces. When Spring starts up it generates proxies for beans. If bean has at least one interface, it uses standard Java proxy. Otherwise it tries to create class-based proxy.

I guess in your case the CGLIB class proxy was used but after Cobertura instrumentation Spring fall back to java proxies. This caused startup error because dependency injection expected class (or CGLIB subclass).

To cut long story short, force CGLIB class proxies and you'll be fine:

<aop:config proxy-target-class="true"/>