Get current authenticated user from security context as key for Spring Cache

Question

I have method without parameters and I want to cache return value. As cache key I want to use current authenticated user from security context

@Cacheable(value = "resultCache", key="#userPrincipal.id")
    public result getResult() {}

Is it possible or my idea is wrong.

Answer 1

You have four options to achieve this:

1. Send the Authentication object as a method parameter:

   @Cacheable(value = "resultCache", key="#authentication.name")
   public Result getResult(Authentication authentication) {}
   

2. Create a custom KeyGenerator and use it in your @Cacheable annotation

   public class CustomKeyGenerator implements KeyGenerator {
       @Override
       public Object generate(Object target, Method method, Object... params) {
           return SecurityContextHolder.getContext().getAuthentication().getName();
       }
   }
   
   @Configuration
   @EnableCaching
   public class CacheConfiguration {
   
       @Bean("customKeyGenerator")
       public KeyGenerator customKeyGenerator() {
           return new CustomKeyGenerator();
       }
   }
   
   @Cacheable(value = "resultCache", keyGenerator="customKeyGenerator")
   public Result getResult() {}
   

3. Create a bean that provides you the key and references it via SPeL in the key property. I would recommend you going for this approach since it allows you to change the value later more easily.

   @Component
   public class CacheKeyProvider {
   
       public String getUsernameKey() {
           return SecurityContextHolder.getContext().getAuthentication().getName();
       }
   }
   
   @Cacheable(value = "resultCache", key="@cacheKeyProvider.getUsernameKey()")
   public Result getResult() {}
   

4. Use the Type SpEL expression

   @Cacheable(value = "resultCache", key="T(org.springframework.security.core.context.SecurityContextHolder.getContext()?.authentication?.name)")
   public Result getResult() {}
   

Note that I used the name property from the Principal in the examples. But if you have a custom Principal object you can cast it and return any property you want.