[SOLVED] my api sometimes need cache data sometimes and sometimes not required?

my api sometimes need cache data sometimes and sometimes not required?

my service sometimes need cache data sometimes and sometimes not required , so i would like to write an method that could clear cache when not needed AND #could someone help me creating a restful, java 8 spring boot#

Solution

Spring provides annotations that can help you with that purpose. If you conditionally need caching, you could for example use the condition parameter of the @Cacheable annotation, for example:

@Cacheable(cacheNames="stuff", condition="#cached")
public List<Stuff> findAll(boolean cached) {
    // ...
}

In this case, if you call findAll(true), it will return the cached result, while if you call findAll(false), it will act as if the annotation isn't there.

Creating a REST API from it isn't that difficult, since your cached parameter could come from a request parameter as well:

@GetMapping("/api/stuff")
@Cacheable(cacheNames="stuff", condition="#cached")
public List<Stuff> findAll(@RequestParam boolean cached) {
    // ...
}

Additionally, if you want to clear the cache, you can use the @CacheEvict annotation:

@CacheEvict("stuff")
public void clearCache() {
}

And just like before, you can turn this is an endpoint:

 @DeleteMapping("/api/stuff/cache")
 @CacheEvict("stuff")
 @ResponseStatus(HttpStatus.NO_CONTENT)
 public void clearCache() {

 }