title: how to binding exchange to exchange for Rabbitmq in spring via xml
body: <p>I know how to binding queues to exchange in spring like this:</p>
  
  <pre><code> &lt;!-- exchange queue binging key --&gt;
       &lt;rabbit:direct-exchange name="skyrim-mq-exchange"
           durable="true" auto-delete="false" id="skyrim-mq-exchange"&gt;
           &lt;rabbit:bindings&gt;
               &lt;rabbit:binding queue="skyrim_queue_one" key="skyrim_queue_one" /&gt;
               &lt;rabbit:binding queue="skyrim_queue_two" key="skyrim_queue_two" /&gt;
           &lt;/rabbit:bindings&gt;
       &lt;/rabbit:direct-exchange&gt;
  </code></pre>
  
  <p>But I can't find some useful demo about Exchange to Exchange bindings via xml.So I really want to know how to config in spring Xml ? Thanks in advance</p>