Preamble: Since Spring-Security 3.2 there is a nice annotation @AuthenticationPrincipal described at the end of this answer. This is the best way to go when you use Spring-Security >= 3.2.
When you:
- use an older version of Spring-Security,
- need to load your custom User Object from the Database by some information (like the login or id) stored in the principal or
- want to learn how a
HandlerMethodArgumentResolver or WebArgumentResolver can solve this in an elegant way, or just want to an learn the background behind @AuthenticationPrincipal and AuthenticationPrincipalArgumentResolver (because it is based on a HandlerMethodArgumentResolver)
then keep on reading — else just use @AuthenticationPrincipal and thank to Rob Winch (Author of @AuthenticationPrincipal) and Lukas Schmelzeisen (for his answer).
(BTW: My answer is a bit older (January 2012), so it was Lukas Schmelzeisen that come up as the first one with the @AuthenticationPrincipal annotation solution base on Spring Security 3.2.)
Then you can use in your controller
public ModelAndView someRequestHandler(Principal principal) {
User activeUser = (User) ((Authentication) principal).getPrincipal();
...
}
That is ok if you need it once. But if you need it several times its ugly because it pollutes your controller with infrastructure details, that normally should be hidden by the framework.
So what you may really want is to have a controller like this:
public ModelAndView someRequestHandler(@ActiveUser User activeUser) {
...
}
Therefore you only need to implement a WebArgumentResolver. It has a method
Object resolveArgument(MethodParameter methodParameter,
NativeWebRequest webRequest)
throws Exception
That gets the web request (second parameter) and must return the User if its feels responsible for the method argument (the first parameter).
Since Spring 3.1 there is a new concept called HandlerMethodArgumentResolver. If you use Spring 3.1+ then you should use it. (It is described in the next section of this answer))
public class CurrentUserWebArgumentResolver implements WebArgumentResolver{
Object resolveArgument(MethodParameter methodParameter, NativeWebRequest webRequest) {
if(methodParameter is for type User && methodParameter is annotated with @ActiveUser) {
Principal principal = webRequest.getUserPrincipal();
return (User) ((Authentication) principal).getPrincipal();
} else {
return WebArgumentResolver.UNRESOLVED;
}
}
}
You need to define the Custom Annotation -- You can skip it if every instance of User should always be taken from the security context, but is never a command object.
@Target(ElementType.PARAMETER)
@Retention(RetentionPolicy.RUNTIME)
@Documented
public @interface ActiveUser {}
In the configuration you only need to add this:
<bean class="org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter"
id="applicationConversionService">
<property name="customArgumentResolver">
<bean class="CurrentUserWebArgumentResolver"/>
</property>
</bean>
@See: Learn to customize Spring MVC @Controller method arguments
It should be noted that if you're using Spring 3.1, they recommend HandlerMethodArgumentResolver over WebArgumentResolver. - see comment by Jay
The same with HandlerMethodArgumentResolver for Spring 3.1+
public class CurrentUserHandlerMethodArgumentResolver
implements HandlerMethodArgumentResolver {
@Override
public boolean supportsParameter(MethodParameter methodParameter) {
return
methodParameter.getParameterAnnotation(ActiveUser.class) != null
&& methodParameter.getParameterType().equals(User.class);
}
@Override
public Object resolveArgument(MethodParameter methodParameter,
ModelAndViewContainer mavContainer,
NativeWebRequest webRequest,
WebDataBinderFactory binderFactory) throws Exception {
if (this.supportsParameter(methodParameter)) {
Principal principal = webRequest.getUserPrincipal();
return (User) ((Authentication) principal).getPrincipal();
} else {
return WebArgumentResolver.UNRESOLVED;
}
}
}
In the configuration, you need to add this
<mvc:annotation-driven>
<mvc:argument-resolvers>
<bean class="CurrentUserHandlerMethodArgumentResolver"/>
</mvc:argument-resolvers>
</mvc:annotation-driven>
@See Leveraging the Spring MVC 3.1 HandlerMethodArgumentResolver interface
Spring-Security 3.2 Solution
Spring Security 3.2 (do not confuse with Spring 3.2) has own build in solution: @AuthenticationPrincipal (org.springframework.security.web.bind.annotation.AuthenticationPrincipal) . This is nicely described in Lukas Schmelzeisen`s answer
It is just writing
ModelAndView someRequestHandler(@AuthenticationPrincipal User activeUser) {
...
}
To get this working you need to register the AuthenticationPrincipalArgumentResolver (org.springframework.security.web.bind.support.AuthenticationPrincipalArgumentResolver) : either by "activating" @EnableWebMvcSecurity or by registering this bean within mvc:argument-resolvers - the same way I described it with may Spring 3.1 solution above.
@See Spring Security 3.2 Reference, Chapter 11.2. @AuthenticationPrincipal
Spring-Security 4.0 Solution
It works like the Spring 3.2 solution, but in Spring 4.0 the @AuthenticationPrincipal and AuthenticationPrincipalArgumentResolver was "moved" to an other package:
(But the old classes in its old packges still exists, so do not mix them!)
It is just writing
import org.springframework.security.core.annotation.AuthenticationPrincipal;
ModelAndView someRequestHandler(@AuthenticationPrincipal User activeUser) {
...
}
To get this working you need to register the (org.springframework.security.web.method.annotation.) AuthenticationPrincipalArgumentResolver : either by "activating" @EnableWebMvcSecurity or by registering this bean within mvc:argument-resolvers - the same way I described it with may Spring 3.1 solution above.
<mvc:annotation-driven>
<mvc:argument-resolvers>
<bean class="org.springframework.security.web.method.annotation.AuthenticationPrincipalArgumentResolver" />
</mvc:argument-resolvers>
</mvc:annotation-driven>
@See Spring Security 5.0 Reference, Chapter 39.3 @AuthenticationPrincipal
