What is the best way of defining key for @Cacheable annotation for Spring

Question

If I am defining a ehcache for a method which doesn't have any parameter.

But in my use case I needs to access the my built cache through it's key.

So please provide me the better way of assigning key on it.

Follow is my code:

@Override
@Cacheable(value = "cacheName", key = "cacheKey")
public List<String> getCacheMethod() throws Exception{

P.S. I am getting the following error when I am trying to access this method from somewhere else.

org.springframework.expression.spel.SpelEvaluationException: EL1008E:(pos 0): Field or property 'cacheKey' cannot be found on object of type 'org.springframework.cache.interceptor.CacheExpressionRootObject'

Well, there are no parameters in your method signature, so even if `key="cacheKey"` *was* a valid SpEL ([it isn't](http://docs.spring.io/spring-framework/docs/4.0.x/spring-framework-reference/html/cache.html#cache-annotations-cacheable-key)) it wouldn't work since there's no such parameter. Hard to tell what you're hoping to achieve since it isn't how `@Cacheable` works - it *does* need method paramaters to use as keys, otherwise the cache will have the capacity of one item. — kryger, Aug 02 '14 at 12:52
you are absolutely correct with the @Cacheable annotation, when i try to access the cache programmatically it's returning the correct object and also if i am trying to access from same class it's working fine, but when i try to access the method from another class its throw the error "EL1008E:(pos 0): Field or property 'cacheKey' cannot be found on object of type 'org.springframework.cache.interceptor.CacheExpressionRootObject'" — BITSSANDESH, Aug 02 '14 at 13:01
It's not clear what you're asking (you seem to have changed the direction of your question three times), sounds like it could be related to THIS problem → http://stackoverflow.com/q/12115996/1240557 ? — kryger, Aug 02 '14 at 13:05
Kryger you almost get it what i am asking, i have solved the problem of proxies by accessing the cache programmatically Cache cache = cacheManager.getCache("cacheName"); if (cache.get("cacheKey") != null) { return (List) cache.get("cacheKey").get(); } and its work fine in same class but when it comes for accessing the cached method from different class it throws the spring spel exception — BITSSANDESH, Aug 02 '14 at 13:11
Have you tried removing `key` from the annotation configuration? As per my first comment it's incorrect for more than one reason. However, it's not clear what's the meaning of the `"cacheKey"` string in the snippet you included in your comment above and how you expect it to be related to the `@Cacheable` annotation. Are you *sure* you read the documentation? — kryger, Aug 02 '14 at 13:28
kryger i think you might be correct, but as can in my previous comment i have to access the cached List from cache object, there i am trying to get the cache object without key then i am getting only null. — BITSSANDESH, Aug 02 '14 at 13:33

score 24 · Accepted Answer · edited Jun 14 '18 at 04:19

24

The method has no parameter, therefore there is no a way to use a parameter/argument as a default key, and you can't use "static text" as a Key, you could do the following:

Declare the following

public static final String KEY = "cacheKey";

must be public
must be static and final

Then

@Override
@Cacheable(value = "cacheName", key = "#root.target.KEY")
public List<String> getCacheMethod() throws Exception{

Done

edited Jun 14 '18 at 04:19

iamprem

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answered Aug 02 '14 at 14:28

Manuel Jordan

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any impact of adding key to cacheable annotation ? – StackOverFlow Jul 02 '20 at 09:52

score 7 · Answer 2 · answered Jun 14 '18 at 06:11

7

In simple cases you can use an easier way: @Cacheable(key = "#root.methodName"), and the key would be equal to annotated method's name

answered Jun 14 '18 at 06:11

Nikolai Shevchenko

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score 4 · Answer 3 · answered Jun 13 '20 at 06:50

You can solve this using a single quote in the key that makes it String again.

@Cacheable(value= CACHE_NAME.PRODUCT_CATLOG, key=" 'products' ")
    public List<Product> findAll() {
        return StreamSupport.stream(productRepository.findAll().spliterator(),false).collect(Collectors.toList());
    }

score 2 · Answer 4 · edited Aug 02 '14 at 13:01

2

Please take a look at this spring doc.

the key refers to the arguments of your method, you are having SpelEvaluationException because cachekey isn't among your method arguments.

edited Aug 02 '14 at 13:01

kryger

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answered Aug 02 '14 at 12:56

Rafik BELDI

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ShadowRay i want to create a key when there is no argument, Can we do it? Or not – BITSSANDESH Aug 02 '14 at 13:04

What is the best way of defining key for @Cacheable annotation for Spring

4 Answers4