Caching with Spring and ehcache doesnt work as expected - spring

Question

I have a Product model object like this -
class ProductDTO {
int id;
String code;
String description;
//getters and setters go here
}
I am writing a service (code below) that looks up products by id or code and returns their description. I am using Spring 4 and ehcache to cache the results.
I have 2 methods - one for lookup by id and one for lookup by code - they are getProductByCode and getProductById. Both return the description as a string. They do so by calling getAllProducts() which returns a list of all products. The callers then search the list for a product matching the id or code and return the description.
getAllProducts() also calls 2 methods with #CachePut for each product - to save the description Strings in cache - by key code and id.
Caching works properly if the same arguments are passed for code or id to to the getProductByCode and getProductById methods. But if I pass a different argument, getAllProducts() is called again.
How do I achieve the desired behavior - where every time a call is made to getAllProducts(), all descriptions get cached and a subsequent call looks up the cache rather than going to the repository?
public class ProductServiceImpl implements ProductService {
#Autowired
ProductsRepository ProductRepo;
#Override
public List<ProductDTO> getAllProducts() {
List<ProductDTO> products = ProductRepo.getAllProducts();
for(ProductDTO prodDTO : products) {
String desc = prodDTO.getDescription();
String code = prodDTO.getCode();
int id = prodDTO.getId();
putDescriptionInCache(desc, code);
putDescriptionInCache(desc, id);
}
return products;
}
#CachePut(value = "products", key = "#id")
public String putDescriptionInCache(String description, int id){
return description;
}
#CachePut(value = "products", key = "#code")
public String putDescriptionInCache(String description, String code){
return description;
}
#Override
#Cacheable(value="products", key="#id")
public String getProductById(Integer id) throws NullPointerException {
String dtoDesc = null;
List<ProductDTO> products = getAllProducts();
for(ProductDTO currDTO : products) {
int currId = currDTO.getId();
if(id.equals(new Integer(currId))) {
dtoDesc = currDTO.getDescription();
}
}
return dtoDesc;
}
#Override
#Cacheable(value="products", key="#code")
public String getProductByCode(String code) throws NullPointerException {
String dtoDesc = null;
List<ProductDTO> products = getAllProducts();
for(ProductDTO currDTO : products) {
String currCode = currDTO.getCode();
if(currCode.equals(code)) {
dtoDesc = currDTO.getDescription();
}
}
return dtoDesc;
}
}

Answer 1

As it was commented by M. Deinum, the problem comes from the annotations, like CachePut or Cacheable, being transformed into an aspect at runtime. And the main limitation with that approach is that calls from the same class are not properly captured.
As you replied yourself in the comments section, moving the annotated methods to another type that is injected in the current one solves the problem.