title: How do I use the key, in a condition in Cacheable annotation
body: <p>I'm caching the results of a function using the @cacheable annotation.
  I have 3 different caches and the key for each one is the user id of the currently logged in user concatenated with an argument in the method .
  On a certain event I want to evict all the cache entries which have the key that starts with that particular user id.
  For example :</p>
  
  <pre><code>@Cacheable(value = "testCache1", key = "'abcdef'")
  </code></pre>
  
  <p>I want the cache evict annotation to be something like :</p>
  
  <pre><code>@CacheEvict(value = "getSimilarVendors", condition = "key.startsWith('abc')")
  </code></pre>
  
  <p>But when I try to implement this it gives me an error :</p>
  
  <pre><code>Property or field 'key' cannot be found on object of type'org.springframework.cache.interceptor.CacheExpressionRootObject' - maybe not      public?
  </code></pre>
  
  <p>What is the correct way to implement this?</p>