日期类型，我们需要统一它在被序列化后的格式，序列化是指把java类型通过网络系统或者IO进行持久化，如把一个java对象保存到txt文件里，或者把java对象保存到redis里，又或者把java对象通过网络以JSON的格式输出到浏览器上。

jackson的日期序列化

    public class JacksonDateSerializerModifier extends BeanSerializerModifier {         @Override         public List<BeanPropertyWriter> changeProperties(SerializationConfig config, BeanDescription beanDesc, List<BeanPropertyWriter> beanProperties) {             for (Object beanProperty : beanProperties) {                 BeanPropertyWriter writer = (BeanPropertyWriter) beanProperty;                 Class<?> clazz = writer.getType().getRawClass();                 if (clazz.equals(Date.class)) {                     writer.assignSerializer(new DateSerializer());                 }             }             return beanProperties;         }              /**          * 格式化日期          */         public class DateSerializer extends JsonSerializer<Object> {             @Override             public void serialize(Object date, JsonGenerator jsonGenerator,                                   SerializerProvider serializerProvider) throws IOException {                 if (date == null) {                     jsonGenerator.writeNumber(StringUtils.EMPTY);                 }                 SimpleDateFormat format = new SimpleDateFormat(yyyy-MM-dd HH:mm:ss);                 TimeZone timeZone = TimeZone.getTimeZone(Asia/Shanghai);                 format.setTimeZone(timeZone);                 String dateString = \ + format.format(date) + \;                 jsonGenerator.writeNumber(dateString);             }         }     } 

通过redisTempleate输出到redis里

 @Bean(name = redisTemplate)     @ConditionalOnClass(RedisOperations.class)//依据RedisOperations是否存在而决定是否注册这个bean     public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) {         RedisTemplate<String, Object> template = new RedisTemplate<String, Object>();         template.setConnectionFactory(factory);         Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);         ObjectMapper om = new ObjectMapper();         om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);         // 日期序列化处理         om.disable(SerializationFeature.WRITE_DATES_AS_TIMESTAMPS);         om.registerModule(new Jdk8Module())                 .registerModule(new JavaTimeModule())                 .registerModule(new ParameterNamesModule());          om.activateDefaultTyping(                 LaissezFaireSubTypeValidator.instance ,                 ObjectMapper.DefaultTyping.NON_FINAL,                 JsonTypeInfo.As.WRAPPER_ARRAY);         jackson2JsonRedisSerializer.setObjectMapper(om);         StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();         // key采用String的序列化方式         template.setKeySerializer(stringRedisSerializer);         // hash的key也采用String的序列化方式         template.setHashKeySerializer(stringRedisSerializer);         // value序列化方式采用jackson         template.setValueSerializer(jackson2JsonRedisSerializer);         // hash的value序列化方式采用jackson         template.setHashValueSerializer(jackson2JsonRedisSerializer);         template.afterPropertiesSet();         return template;     }