CODEWITHSUNDEEP
spring-cache
Ramesh BS
Ramesh BS

Reputation: 21

Refresh Cache in Spring

How I can refresh spring cache when I inserted data into Database through my services and when I added data directly into database.Can we achieve this?.

Note:

I am using following libs 1)net.sf.json-lib 2)spring-support-context

Upvotes: 2

Views: 7613

Answers (1)

John Blum
John Blum

Reputation: 7981

through my services

This is typically achieved in your application's services (e.g. @Service application components) using the Spring @Cacheable, @CachePut annotations, for example...

@Service
class BookService {

  @Cacheable("Books")
  Book findBook(ISBN isbn) {
    ...
    return booksRepository().find(isbn);
  }

  @CachePut(cacheNames = "Books", key = "#book.isbn")
  Book update(Book book) {
    ...
    return booksRepository.save(book);
  }
}

Both @Cacheable and @CachePut will update the cache provider as the underlying method may callback through to the underlying database.

and when I added data directly into database

This is typically achieved by the underlying cache store. For example, in GemFire, you can use a CacheLoader to "read-through" (to your underlying database perhaps) on "cache misses". See GemFire's user guide documentation on "How Data Loaders Work" as an example and more details.

So, back to our example, if the "Book (Store)" database was updated independent of the application (using Spring's Caching Annotation support and infrastructure), then a developer just needs to define a strategy on cache misses. And, in GemFire that could be a CacheLoader, and when...

bookService.find(<some isbn>);

is called resulting in a "cache miss", GemFire's CacheLoader will kick in, load the cache with that book and Spring will see it as a "cache hit".

Of course, our implementation of bookService.find(..) went to the underlying database anyway, but it only retrieves a "single" book. A loader could be implemented to populate an entire set (or range) of books based on some criteria (such as popularity), where the application service expects those particular set of books to be searched for by potential customers, using the application, first, and pre-cache them.

So, while Spring's Cache annotations typically work per entry, a cache store specific strategy can be used to prefetch and, in-a-way, "refresh" the cache, lazily, on the first cache miss.

In summary, while the former can be handled by Spring, the "refresh" per say is typically handled by the caching provider (e.g. GemFire).

Hopefully this gives you some ideas.

Cheers, John

Upvotes: 1

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