title: What does Spring's @Cacheable do when placed on a method returning a list?
body: <p>I've looked everywhere online for a simple answer to the above question, and just can't find it. I have a method like:</p>
  
  <pre><code>@Cacheable(cacheNames = "objects")
  public List&lt;Object&gt; get() { .. }
  </code></pre>
  
  <p>I'm using EhCache 2.10.0 with Spring Framework 4.2.1, and I can see the following output for this method:</p>
  
  <pre><code>Adding cacheable method 'get' with attribute: [CacheableOperation[public java.util.List com.example.DAO.get()] caches=[objects] | key='' ...
  </code></pre>
  
  <p>also (in later logging)</p>
  
  <pre><code>Computed cache key 'SimpleKey []' for operation ...
  </code></pre>
  
  <p>What is the @Cacheable annotation <em>supposed</em> to do in this situation? Place each object in the cache keyed by hashCode (as hinted at elsewhere)? Or just plonk the whole list as-is into the cache under some list-based hashCode?</p>