title: See if field exists in class
body: <p>I have a class with various variables</p>
  
  <pre><code>public class myClass{
  
      public int id;
      public String category;
      public String description;
      public String start;
      public String end;
  }
  </code></pre>
  
  <p>Is there a way to check, either by creating an internal function or checking from the calling object, whether or not a variable exists?</p>
  
  <p>E.g.  To check whether myClass contains a variable called "category" (it does).  Or whether it contains a category called "foo" (it does not).</p>