How do I convert from YAML to JSON in Java?

Question

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

--- 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 

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 System.out.println(json); 

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.

Answer 1

Here is an implementation that uses Jackson:

String convertYamlToJson(String yaml) {     ObjectMapper yamlReader = new ObjectMapper(new YAMLFactory());     Object obj = yamlReader.readValue(yaml, Object.class);      ObjectMapper jsonWriter = new ObjectMapper();     return jsonWriter.writeValueAsString(obj); } 

Requires:

compile('com.fasterxml.jackson.dataformat:jackson-dataformat-yaml:2.7.4')