java - 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'

Answer 1

该方法没有参数，因此无法使用参数/参数作为默认键，并且您不能使用“静态文本”作为键，您可以执行以下操作：

声明以下内容

public static final String KEY = "cacheKey";

• 一定是public
• 必须是static和final

然后

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

完毕

Answer 2

在简单的情况下，您可以使用更简单的方法：@Cacheable(key = "#root.methodName")，并且键将等于注释方法的名称

Answer 3

请看一下这个春季文档。

关键是指您的方法的参数，SpelEvaluationException因为cachekey不在您的方法参数中。

Answer 4

您可以使用键中的单引号将其再次变为 String 来解决此问题。

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