引用Maven库：

        <!-- Jackson -->          <dependency>              <groupId>com.fasterxml.jackson.core</groupId>              <artifactId>jackson-core</artifactId>              <version>2.4.3</version>          </dependency>          <dependency>              <groupId>com.fasterxml.jackson.core</groupId>              <artifactId>jackson-databind</artifactId>              <version>2.4.3</version>          </dependency>

代码细节：

public class JacksonUtil {        private static final Logger logger = LoggerFactory.getLogger(JacksonUtil.class);        private static final ObjectMapper objectMapper = new ObjectMapper();        static {          /**           * 默认非空不输出，时间格式           */          objectMapper.setSerializationInclusion(JsonInclude.Include.NON_NULL);          objectMapper.setDateFormat(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));      }        /**       * 将 Java 对象转为 JSON 字符串       */      public static <T> String toJSON(T obj) {          String jsonStr;          try {              jsonStr = objectMapper.writeValueAsString(obj);          } catch (Exception e) {              logger.error("Java 转 JSON 出错！", e);              throw new RuntimeException(e);          }          return jsonStr;      }        /**       * 将 JSON 字符串转为 Java 对象       */      public static <T> T fromJSON(String json, Class<T> type) {          T obj;          try {              obj = objectMapper.readValue(json, type);          } catch (Exception e) {              logger.error("JSON 转 Java 出错！", e);              throw new RuntimeException(e);          }          return obj;      }  }