java - how to convert json string to map dynamically

Question

I have a json ouput like this -

  {"menu": {
   "id": "12",
   "value": "File",
   "popup": {
       "menuitem": [
                  {"op1": "New", "op11": "CreateNewDoc()"},
                  {"op2": "Open", "op21": "OpenDoc()"},
                  {"op3": "Close", "op31": "CloseDoc()"}
                   ]
            }
      }}

I want whatever is the key and order, it should return the key-value pair in a map like this and I do not want to harcode any key-

      id=12
      value=File
      op1=New
      op11=CreateNewDoc()
      op2=Open
      op21=OpenDoc()
      op3=Close
      op31=CloseDoc()

how will I do it?

Answer 1

Using the standard Java JSON Stream APIs, this will produce the java.util.Map you want:

Map<String, String> values = new HashMap<>();
String keyName = null;

JsonParser jsonParser = Json.createParser(new StringReader(json));

while (jsonParser.hasNext())
{
  JsonParser.Event event = jsonParser.next();

  if (JsonParser.Event.KEY_NAME.equals(event))
  {
    keyName = jsonParser.getString();
  }
  else if (JsonParser.Event.VALUE_STRING.equals(event))
  {
    values.put(keyName, jsonParser.getString());
  }
}