title: Can not find a (Map) Key deserializer for type [simple type, class ...]
body: <p>I have a domain object that has a Map:</p>
  <pre><code>private Map&lt;AutoHandlingSlotKey, LinkedHashSet&lt;AutoFunction&gt;&gt; autoHandling;
  </code></pre>
  <p>When I serialize the object, I get this:</p>
  <pre><code>&quot;autoHandling&quot; : [ &quot;java.util.HashMap&quot;, {
  } ],
  </code></pre>
  <p>This Map's key is a custom Object:</p>
  <pre><code>public class AutoHandlingSlotKey implements Serializable {
      private FunctionalArea slot; // ENUM
      private String returnView;   // ENUM
  </code></pre>
  <p>So, I am not sure how to correct this exception I keep getting when I deserialize the object:</p>
  <pre><code>org.codehaus.jackson.map.JsonMappingException: Can not find a (Map) Key deserializer for type [simple type, class com.comcast.ivr.core.domain.AutoHandlingSlotKey]
  </code></pre>
  <p>How to correct this issue? I do <em>not</em> have access to the domain object to modify.</p>