title: Setting a default value for empty json field
body: <p>I have to parse a json whom a field can be empty:</p>
  
  <pre><code>{"fullField":"ok","canBeEmpty":""}
  </code></pre>
  
  <p>if I try to parse this string overall parsing fails with a "no value for canBeEmpty".
  For each json item I execute:</p>
  
  <pre><code>json_data.getString("field"); //throws exception if empty
  </code></pre>
  
  <p>I'd like to still keep the parsing, setting the canBeEmpty value to a default string...is it possibile?</p>