Miguel A. Carrasco Miguel A. Carrasco - 4 months ago 321
Java Question

How do I convert from YAML to JSON in Java?

I just want to convert a string that contains a yaml into another string that contains the corrseponding converted json using Java.

For example supose that I have the content of this yaml

uuid: 8a8cbf60-e067-11e3-8b68-0800200c9a66
name: On formally undecidable propositions of Principia Mathematica and related systems I.
author: Kurt Gödel.
- tag:
uuid: 98fb0d90-e067-11e3-8b68-0800200c9a66
name: Mathematics
- tag:
uuid: 3f25f680-e068-11e3-8b68-0800200c9a66
name: Logic

in a String called yamlDoc:

String yamlDoc = "---\npaper:\n uuid: 8a... etc...";

I want some method that can convert the yaml String into another String with the corresponding json, i.e. the following code

String yamlDoc = "---\npaper:\n uuid: 8a... etc...";
String json = convertToJson(yamlDoc); // I want this method

should print:

"paper": {
"uuid": "8a8cbf60-e067-11e3-8b68-0800200c9a66",
"name": "On formally undecidable propositions of Principia Mathematica and related systems I.",
"author": "Kurt Gödel."
"tags": [
"tag": {
"uuid": "98fb0d90-e067-11e3-8b68-0800200c9a66",
"name": "Mathematics"
"tag": {
"uuid": "3f25f680-e068-11e3-8b68-0800200c9a66",
"name": "Logic"

I want to know if exists something similar to the convertToJson() method in this example.

I tried to achieve this using SnakeYAML, so this code

Yaml yaml = new Yaml();
Map<String,Object> map = (Map<String, Object>) yaml.load(yamlDoc);

constructs a map that contain the parsed YAML structure (using nested Maps). Then if there is a parser that can convert a map into a json String it will solve my problem, but I didn't find something like that neither.

Any response will be greatly appreciated.


Thanks to HotLicks tip (in the question comments) I finally achieve the conversion using the libraries org.json and SnakeYAML in this way:

private static String convertToJson(String yamlString) {
    Yaml yaml= new Yaml();
    Map<String,Object> map= (Map<String, Object>) yaml.load(yamlString);

    JSONObject jsonObject=new JSONObject(map);
    return jsonObject.toString();

I don't know if it's the best way to do it, but it works for me.