Question

How to manually authenticate user by adding ManualUserDetails extends org.springframework.security.core.userdetails.UserDetails into SecurityContextHolder.setAuthentication(..) ?

Answer 1

I hope you have created a custom authentication provider (called myAuthenticationProvider below) as follows:

<authentication-manager>
    <authentication-provider ref='myAuthenticationProvider'/>
</authentication-manager>

In the bean myAuthenticationProvider you need to provide a userDetails service, that would load the your ManualUserDetails.