String jsonString = "{ \"key\": \"value\" }"; JSONObject jsonObject = JSON.parseObject(jsonString); String value = jsonObject.getString("key"); System.out.println(value); ParserConfig.getGlobalInstance().addAccept("com.example.model."); String jsonString = "{'name': 'John', 'age': 25}"; if (jsonString.matches("[a-zA-Z0-9]*")) { } else { } Feature.SortFeidFastMatch.getMask(); ~Feature.AllowSingleQuotes.getMask();