title: Retrieving values from nested JSON Object
body: <p>I've got JSON file, which I want to parse.
  The JSON file ("myfile") has format as follows:</p>
  
  <pre><code>{
      "LanguageLevels": {
          "1": "Początkujący",
          "2": "ŚrednioZaawansowany",
          "3": "Zaawansowany",
          "4": "Ekspert"
      }
  }
  </code></pre>
  
  <p>I want to retrieve value (ŚrednioZaawansowany) of Key 2 from Language Levels.</p>
  
  <pre><code>import java.io.FileNotFoundException;
  import java.io.FileReader;
  import java.io.IOException;
  import java.util.Iterator;
  import org.json.simple.JSONArray;
  import org.json.simple.JSONObject;
  import org.json.simple.parser.JSONParser;
  import org.json.simple.parser.ParseException;
  
  public class JsonSimpleExample {
  public static void main(String[] args) {
  
  JSONParser parser = new JSONParser();
  
  try {
  
      Object obj = parser.parse(new FileReader("myfile"); 
      JSONObject jsonObject = (JSONObject) obj;
      JSONObject jsonChildObject = (JSONObject)jsonObject.get("LanguageLevels");
  </code></pre>
  
  <p>What to do next? How I can iterate over it?</p>