title: Will Spring's @CachePut annotation work with a void return type?
body: <p>I am attempting to implement caching in my application using Ehcache and the Spring 3.1 built in caching annotations (@Cacheable, @CacheEvict, and @CachePut).  </p>
  
  <p>I have created a cache as follows:</p>
  
  <pre><code>@Cacheable(value = "userCache", key = "#user.id")
  public List&lt;User&gt; getAllUsers() {
  ...
  }
  </code></pre>
  
  <p>I am attempting to update this cache with a new value using the @CachePut annotation as below:</p>
  
  <pre><code>@CachePut(value = "userCache", key = "#user.id")
  public void addUser(User user) {
  ...
  }
  </code></pre>
  
  <p>However, the new "User" is not being added to the cache.  Is this because of the void return type?</p>