How to write custom interceptor for spring cache(#cachable) - spring-boot

Question

I am caching data using spring cache. Now i want to encrypt few data before writing into cache and decrypt data while reading. So is there any way i can write custom interceptor/aop for #cachable annotation

Answer 1

Instead of using AOP you can simply use a decorator for your Cache and CacheResolver.
public class EncodingCacheResolver implements CacheResolver {
private final CacheResolver delegate;
public EncodingCacheResolver(CacheResolver delegate) {
this.delegate=delegate;
}
#Override
public Collection<? extends Cache> resolveCaches(CacheOperationInvocationContext<?> context) {
Collection<Cache> result = delegate.resolveCaches(context);
return result.stream().map(EncodingCache::new).collect(Collectors.toLlist());
}
}
The cache implementation
public class EncodingCache implements Cache {
private final Cache delegate;
public EncodingCache(Cache delegate) {
this.delegate=delegate;
}
public String getName() {
return delegate.getName();
}
public Object getNativeCache() {
return delegate.getNativeCache();
}
public void evict(Object key) {
delegate.evict(key)
}
public void put(Object key, Object value) {
Object encodedValue = encode(value);
this.delegate.put(key, encodedValue);
}
public <T> T get(Object key, Class<T> type) {
Object encodedValue = delegate.get(key, type);
return decode(encodedValue);
}
// Other Cache methods omitted but the pattern is the same
private Object encode(Object value) {
// encoding logic here
}
private Object decode(Object value) {
// decoding logic here
}
}
Then some configuration
#Configuration
#EnableCache
public void CacheConfiguration {
#Bean
public CacheResolver cacheResolver(CacheManager cacheManager) {
return new EncodingCacheResolver(SimpleCache.of(cacheManager));
}
}
Haven't tested the implementation, typed it from the top of my head. But this should more or less be what you need. You don't really need AOP for this.