title: arbitrary parameters in a Spring-boot request
body: <p>Apologies up front. This should be a 100% google-able question, but I seem to be using the wrong vocabulary.</p>
  
  <p>On an http query, parameters are passed as part of the url string:</p>
  
  <pre><code>curl http://my.host.com/controllerName/actionName?a=b&amp;c=d&amp;e=f&amp;param1=apple&amp;param2=oran
  </code></pre>
  
  <p>The application specifies a few parameters, and those could be optional:</p>
  
  <pre><code>public HttpEntity&lt;MyResults&gt; actionName(
          @RequestParam(value = "param1", required = true, defaultValue = "Electric Bulb") String param1,
          @RequestParam(value = "param2", required = false ) String param2
          ) throws SomeException { etc}
  </code></pre>
  
  <p>What I want is if the user passes in some set of params <em>other than what was specified</em>, to capture that in one or more strings to pass downstream. For example, in some languages the 'leftover' query parameters would be a map {param, value}.</p>
  
  <p>Is this possible in Java's type system? If so, how? And what is the right name for them?</p>