Cache not refreshing when being called from a asynchrounous function in Spring

Question

I am calling a function which has CacheEvict annotation on it. This is being called from a function that is itself executed asynchronously.

It seems that the cache is not being evicted after the function has been executed.

Here is sample code

@Async("executor1")
public void function1()
{
    // do something

    anotherFunction("name", 123, 12);

   // do something more

}

@CacheEvict(cacheNames = {"cache1", "cache2", "cache3"}, key = "#testId")
public List<Integer> anotherFunction(String name, int testId, int packageId)
{
  // some code here
}

What I want is that entries corresponding to testId should be cleared from all the caches. However, in another call, I can see old entries of cache1. function1 is being called from the controller. Both these functions are present inside the service. Now, Is this configuration correct? If yes, What may be the possible reasons that cache is not being cleared?

Any help appreciated. Thanks in advance.

Answer 1

I think your problem is that Spring proxies are not reentrant. To implement Async and CacheEvict, Spring creates a proxy. So, in your example, the call stack will be:

A -> B$$proxy.function1() -> B.function1() -> B.anotherFunction()

B$$proxy contains the logic for async and eviction. Which won't apply when calling directly anotherFunction. In fact, even if you remove the @Async, it will still don't work.

A trick you can use is to inject the proxied bean into the class. To delegate to the proxy of the class instead this.

public class MyClass {    
  private MyClass meWithAProxy;

  @Autowired
  ApplicationContext applicationContext;

  @PostConstruct
  public void init() {
    meWithAProxy = applicationContext.getBean(MyClass.class);
  }

  @Async("executor1")
  public void function1() {
    meWithAProxy.anotherFunction("name", 123, 12);
  }

  @CacheEvict(cacheNames = "cache1", key = "#testId")
  public List<Integer> anotherFunction(String name, int testId, int packageId) {
    return Collections.emptyList();
  }

}

It works. But there's a catch. If you now call anotherFunction directly, it won't work. I consider this to be a Spring bug and will file it as is.