<dependencies> <dependency> <groupId>org.json</groupId> <artifactId>json</artifactId> <version>20210307</version> </dependency> </dependencies> import org.json.JSONObject; JSONObject jsonObject = new JSONObject(); jsonObject.put("age", 25); String jsonString = jsonObject.toString(); JSONObject jsonObject = new JSONObject(jsonString); String name = jsonObject.getString("name"); int age = jsonObject.getInt("age"); String gender = jsonObject.getString("gender"); boolean containsName = jsonObject.has("name"); boolean containsAddress = jsonObject.has("address"); boolean isString = jsonObject.get("name") instanceof String; boolean isNumber = jsonObject.get("age") instanceof Number;