### Question:
JSONUtils { public static boolean checkJsonValid(String json) { if (StringUtils.isEmpty(json)) { return false; } try { objectMapper.readTree(json); return true; } catch (IOException e) { logger.error("check json object valid exception!", e); } return false; } private  JSONUtils(); static ArrayNode createArrayNode(); static ObjectNode createObjectNode(); static JsonNode toJsonNode(Object obj); static String toJsonString(Object object, SerializationFeature feature); static T parseObject(String json, Class<T> clazz); static List<T> toList(String json, Class<T> clazz); static boolean checkJsonValid(String json); static String findValue(JsonNode jsonNode, String fieldName); static Map<String, String> toMap(String json); static Map<K, V> toMap(String json, Class<K> classK, Class<V> classV); static String toJsonString(Object object); static ObjectNode parseObject(String text); static ArrayNode parseArray(String text);  }### Answer:
@Test public void testCheckJsonValid() { Assert.assertTrue(JSONUtils.checkJsonValid("3")); Assert.assertFalse(JSONUtils.checkJsonValid("")); }