title: Mapping optional query params in WSO2 ESB API resource
body: <p>I have to mapping query params to send request to endpoint in API resource in WSO2 ESB.</p>
  
  <p>Those query params are optional. For example, the following are examples of calls to resource:</p>
  
  <pre><code>http://server:port/service?q1={q1}
  http://server:port/service?q2={q2}&amp;q3={q3}
  </code></pre>
  
  <p>I need to have a single resource to do this.</p>
  
  <p>How can I do this?</p>
  
  <p>Basically, I have to read query params in request and put it in the call to endpoint uri.</p>