jackson

常用方法

@Slf4j
public class JsonUtils {

    private static final ObjectMapper MAPPER = defaultObjectMapper(new ObjectMapper());

    private JsonUtils() {
    }

    /**
     * 将Map对象序列化为json字符串
     *
     * @param map
     * @return
     */
    public static String toJsonExcludeByteAry(Map<String, Object> map) {
        try {
            Map<String, Object> newMap = new HashMap<>();
            for (String key : map.keySet()) {
                Object val = map.get(key);
                if (!(val instanceof byte[])) {
                    newMap.put(key, val);
                }
            }
            return MAPPER.writeValueAsString(newMap);
        } catch (JsonProcessingException e) {
            // 使用spring的异常类
            throw new JsonParseException(e);
        }
    }

    /**
     * 序列化：将对象序列化为json字符串
     *
     * @param object
     * @param <T>
     * @return
     */
    public static <T> String toJson(T object) {
        try {
            return MAPPER.writeValueAsString(object);
        } catch (JsonProcessingException e) {
            // 使用spring的异常类
            throw new JsonParseException(e);
        }
    }


    /**
     * 反序列化：json字符串反序列化为对象
     *
     * @param json
     * @param tClass
     * @param <T>
     * @return
     */
    public static <T> T fromJson(String json, Class<T> tClass) {
        try {
            return (T) MAPPER.readValue(json, tClass);
        } catch (JsonProcessingException e) {
            // 使用spring的异常类
            throw new JsonParseException(e);
        }
    }

    /**
     * 反序列化：处理泛型
     *
     * @param jsonString
     * @param typeReference
     * @param <T>
     * @return
     */
    public static <T> T fromJson(String jsonString, TypeReference<T> typeReference) {
        try {
            return MAPPER.readValue(jsonString, typeReference);
        } catch (JsonProcessingException e) {
            // 使用spring的异常类
            log.error("json:{}", jsonString, e);
            throw new JsonParseException(e);
        }
    }

　　public static ObjectMapper defaultObjectMapper(ObjectMapper objectMapper) {
        objectMapper.findAndRegisterModules();
        // 日期序列化为数字
        objectMapper.disable(SerializationFeature.WRITE_DATE_TIMESTAMPS_AS_NANOSECONDS);
        objectMapper.disable(DeserializationFeature.READ_DATE_TIMESTAMPS_AS_NANOSECONDS);
        // 序列化不支持的类型不报错
        objectMapper.disable(SerializationFeature.FAIL_ON_EMPTY_BEANS);
        objectMapper.disable(SerializationFeature.FAIL_ON_SELF_REFERENCES);
        objectMapper.disable(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES);
        // 仅序列化非空字段
        //objectMapper.setSerializationInclusion(JsonInclude.Include.NON_EMPTY);
        // 时间设置系统默认时区
        objectMapper.setTimeZone(TimeZone.getDefault());
        // 默认的filter
        objectMapper.setFilterProvider(new SimpleFilterProvider().setDefaultFilter(SimpleBeanPropertyFilter.serializeAll()));

        return objectMapper;
    }

}