Spring cache all elements in list separately

I'll self answer my question since no one gave any and could help others.

The problem I had when dealing with this issue was a problem of misconception of Cache usage. My need posted on this question was related to how to update members of a cached list (method response). This problem cannot be solved with cache, because the cached value was the list itself and we cannot update a cached value partially.

The way I wanted to tackle this problem is related to a "map" or a distributed map, but I wanted to use the @Cacheable annotation. By using a distributed map would have achieved what I asked in my question without using @Cacheable. So, the returned list could have been updated.

So, I had (wanted) to tackle this problem using @Cacheable from other angle. Anytime the cache needed to update I refreshed it with this code.

I used below code to fix my problem:

@Cacheable("users")List<User> list() {    return userRepository.findAll()}// Refresh cache any time the cache is modified@CacheEvict(value = "users", allEntries = true") void create(User user) {    userRepository.create(user)}@CacheEvict(value = "users", allEntries = true") void update(User user) {    userRepository.update(user)}@CacheEvict(value = "users", allEntries = true") void delete(User user) {    userRepository.delete(user)}

In addition, I have enabled the logging output for spring cache to ensure/learn how the cache is working:

# Log Spring Cache outputlogging.level.org.springframework.cache=TRACE

Not Sure if, using Spring's @Cacheable is a hard constraint for you, but this essentially worked for me.

I tried using Spring's RedisTemplate and Redis HasMap data-structure for storing the list elements.

Store a single User:

redisTemplate.opsForHash().put("usersRedisKey" ,user.id,user);

Storing List of Users:

Need to map this with user.id first

Map<Long, User> userMap = users.stream()                .collect(Collectors.toMap(User::getId, Function.identity()));    redisTemplate.opsForHash().putAll("usersRedisKey", userMap);

Get single user from Cache:

redisTemplate.opsForHash().get("usersRedisKey",user.id);

Get list of users:

redisTemplate.opsForHash().multiGet("usersRedisKey", userIds); //userIds is List of ids

Delete user from List:

redisTemplate.opsForHash().delete("usersRedisKey",user.id);

Similarly you could try using other operations from Redis HashMap to update individual objects based on ids.

I understand I am quite late to the party here, but do let me know if this works for you.

Try below given solution:

  @Caching(put = @CachePut(cacheNames = "product", key = "#result.id"),            evict = @CacheEvict(cacheNames = "products", allEntries = true))    public Product create(ProductCreateDTO dto) {        return repository.save(mapper.asProduct(dto));    }        @Caching(put = @CachePut(cacheNames = "product", key = "#result.id"),            evict = @CacheEvict(cacheNames = "products", allEntries = true))    public Product update(long id, ProductCreateDTO dto) {        return repository.save(mapper.merge(dto, get(id)));    }    @Caching(evict = {            @CacheEvict(cacheNames = "product", key = "#result.id"),            @CacheEvict(cacheNames = "products", allEntries = true)    })    public void delete(long id) {        repository.delete(get(id));    }    @Cacheable(cacheNames = "product", key = "#id")    public Product get(long id) {        return repository.findById(id).orElseThrow(() -> new RuntimeException("product not found"));    }    @Cacheable(cacheNames = "products", key = "#pageable")    public Page<Product> getAll(Pageable pageable) {        return repository.findAll(pageable);    }