The ResourceConfig instance does not contain any root resource classes

Have you tried adding

<init-param>
  <param-name>com.sun.jersey.config.property.packages</param-name>
  <param-value>my.package.name</param-value>
</init-param>

to your SpringServlet definition? Obviously replace my.package.name with the package that AdminUiResource is in and make sure it is in the classpath.