Java对象以Hash结构存入Redis详解

Key:{
	filed: value,
	filed: value,
	filed: value,
	....
}

@Autowired
    private RedisTemplate redisTemplate;
    /**
     * 测试Redis存Hash结构数据
     */
    @Test
    void testSaveRedisHash() throws JsonProcessingException {
        User user = new User();user.setUserId(111);user.setPassword("psw");user.setName("张三");user.setCreateTime(new Date());
        ObjectMapper objectMapper = new ObjectMapper();
        redisTemplate.setHashKeySerializer(RedisSerializer.string());
        redisTemplate.setHashValueSerializer(RedisSerializer.string());
        // key, filed, value
        redisTemplate.opsForHash().put("testHash", "hashKey", "hashValue");
        // 直接写JSON，并没有什么卵用
        redisTemplate.opsForHash().put("testHash", "user", objectMapper.writeValueAsString(user));
        TestRedisHashObject testObj = new TestRedisHashObject(1, "测试时", new Date(), user);
        // 依赖第三方commons.beanUtils包
        redisTemplate.opsForHash().putAll("BeanUtilsHashMapper实现对象转hash",new BeanUtilsHashMapper<>(TestRedisHashObject.class).toHash(testObj));
        // flatmap为true，才开启json属性path扁平化。
        // jackson2HashMapper中默认的ObjectMapper对时间序列化成了long，而putAll方法中对long无法直接强转成string。会发生ClassCastException
        // decoratingStringHashMapper：将map中的所有kv都使用StringValueOf进行了增强
        redisTemplate.opsForHash().putAll("Jackson2HashMapper实现对象转hash",new DecoratingStringHashMapper<>(new Jackson2HashMapper(true)).toHash(testObj));
        // ObjectHashMapper返回的Map的泛型是Map<byte[], byte[]> 需要自己手动转换。不推荐使用
        // decoratingStringHashMapper：String.valueOf方法无法对byte[]进行转成字符串
        // redisTemplate.opsForHash().putAll("ObjectHashMapper实现对象转hash",new ObjectHashMapper().toHash(testObj));
    }
    /**
     * 测试Redis取Hash结构数据
     */
    @Test
    void testGetRedisHash(){
        redisTemplate.setHashKeySerializer(RedisSerializer.string());
        redisTemplate.setHashValueSerializer(RedisSerializer.string());
        String key = "Jackson2HashMapper实现对象转hash";
        Object o = new Jackson2HashMapper(true).fromHash(redisTemplate.opsForHash().entries(key));
        TestRedisHashObject testObj = (TestRedisHashObject) o;
        System.out.println(testObj);
        Long newCount = redisTemplate.opsForHash().increment(key, "count", 10L);
        System.out.println("newCount = " + newCount);
        o = new Jackson2HashMapper(true).fromHash(redisTemplate.opsForHash().entries(key));
        testObj = (TestRedisHashObject) o;
        System.out.println(testObj);
		Object c = redisTemplate.opsForHash().get(key, "count");
        Long count = (Long) c;
        System.out.println("getCount = " + count);
    }