Spring AOP pointcut that matches annotation on interface
- by seanizer
Hello,
this is my first post here, so I apologize in advance for any stupidity on my side.
I have a service class implemented in Java 6 / Spring 3 that needs an annotation to restrict access by role.
I have defined an annotation called RequiredPermission that has as its value attribute one or more values from an enum called OperationType:
public @interface RequiredPermission {
/**
* One or more {@link OperationType}s that map to the permissions required
* to execute this method.
*
* @return
*/
OperationType[] value();}
public enum OperationType {
TYPE1,
TYPE2;
}
package com.mycompany.myservice;
public interface MyService{
@RequiredPermission(OperationType.TYPE1)
void myMethod( MyParameterObject obj );
}
package com.mycompany.myserviceimpl;
public class MyServiceImpl implements MyService{
public myMethod( MyParameterObject obj ){
// do stuff here
}
}
I also have the following aspect definition:
/**
* Security advice around methods that are annotated with
* {@link RequiredPermission}.
*
* @param pjp
* @param param
* @param requiredPermission
* @return
* @throws Throwable
*/
@Around(value = "execution(public *"
+ " com.mycompany.myserviceimpl.*(..))"
+ " && args(param)" + // parameter object
" && @annotation( requiredPermission )" // permission annotation
, argNames = "param,requiredPermission")
public Object processRequest(final ProceedingJoinPoint pjp,
final MyParameterObject param,
final RequiredPermission requiredPermission) throws Throwable {
if(userService.userHasRoles(param.getUsername(),requiredPermission.values()){
return pjp.proceed();
}else{
throw new SorryButYouAreNotAllowedToDoThatException(
param.getUsername(),requiredPermission.value());
}
}
The parameter object contains a user name and I want to look up the required role for the user before allowing access to the method.
When I put the annotation on the method in MyServiceImpl, everything works just fine, the pointcut is matched and the aspect kicks in. However, I believe the annotation is part of the service contract and should be published with the interface in a separate API package. And obviously, I would not like to put the annotation on both service definition and implementation (DRY).
I know there are cases in Spring AOP where aspects are triggered by annotations one interface methods (e.g. Transactional). Is there a special syntax here or is it just plain impossible out of the box.
PS: I have not posted my spring config, as it seems to be working just fine. And no, those are neither my original class nor method names.
Thanks in advance, Sean
PPS: Actually, here is the relevant part of my spring config:
<aop:aspectj-autoproxy proxy-target-class="false" />
<bean class="com.mycompany.aspect.MyAspect">
<property name="userService" ref="userService" />
</bean>
