YAMLReader reader = new YAMLReader(new FileReader("data.yaml")); Map<String, Object> data = reader.read(); String value = (String) data.get("key"); System.out.println(value); YAMLWriter writer = new YAMLWriter(new FileWriter("data.yaml")); Map<String, Object> data = new HashMap<>(); data.put("key", "value"); writer.write(data); writer.close(); YAMLConfiguration config = new YAMLConfiguration("config.yaml"); String value = config.getString("key"); System.out.println(value); config.setProperty("key", "new value"); config.save();