Deserialization through JCache failing with ClassCastException

I am using Redisson as Redis client to store a key-value pair <String, LocalDateTime>. It’s configured to be used through the JCache API (JSR-107).

It’s storing values like 2018-01-23T11:59:34.997834 but in the cache#get invocation is trying to return a String giving a ClassCastException . It compiles perfectly, cache#get returning LocalDateTime, but if fails in execution.

Am I missing something here or is there some problem using it with the JCache API?

    @Test
    public void getCacheInline() {
        // Configuration
        Config redissonCfg = new Config();
        redissonCfg
            .setCodec(new JsonJacksonCodec(buildObjectMapper()))
            .useSingleServer()
            .setAddress("redis://redis:6379");

        MutableConfiguration<String, LocalDateTime> jcacheConfig = new MutableConfiguration<String, LocalDateTime>()
            .setTypes(String.class, LocalDateTime.class)
            .setExpiryPolicyFactory((Factory<ExpiryPolicy>) () -> new CreatedExpiryPolicy(new Duration(SECONDS, 100)));

        Configuration<String, LocalDateTime> configuration = RedissonConfiguration.fromConfig(redissonCfg, jcacheConfig);

        // Cache creation
        Cache<String, LocalDateTime> cache = cacheManager.createCache(CACHE_NAME, configuration);

        // Put
        LocalDateTime expectedDateTime = LocalDateTime.now();
        cache.put("testKey", expectedDateTime);

        // Get
        // In this line: java.lang.ClassCastException: java.base/java.lang.String cannot be cast to java.base/java.time.LocalDateTime
        LocalDateTime actualDateTime = cache.get("testKey");
        assertThat(actualDateTime, is(equalTo(expectedDateTime)));
    }

    private ObjectMapper buildObjectMapper() {
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.registerModule(new JavaTimeModule());
        objectMapper.configure(FAIL_ON_UNKNOWN_PROPERTIES, false);
        objectMapper.configure(WRITE_DATES_AS_TIMESTAMPS, false);
        objectMapper.configure(READ_DATE_TIMESTAMPS_AS_NANOSECONDS, false);
        objectMapper.setSerializationInclusion(NON_NULL);
        return objectMapper;
    }

[prosonf]

I’m seeing that wrapping in another object is working.

    public static class Value {
        private LocalDateTime value;
        ...
    }

It serialised a json string with @class property, and then at deserialising time it has all the types there.

Anyway, it doesn’t work with plain LocalDateTime objects, or any object from Java 8 Time API I would say.

@mrniko, Redisson team, I leave to you progressing this issue any further. As I cannot wait much longer, I think this workaround will do it for me if not I’ll go with something different.

Thanks

[rajendrag]

I am seeing this issue with RMapCache now. But, in my case, there could be many other object types that could be the values of this map (I have one RMapCache for whole application, this was recommended in one of the redisson documentation). I can not use the JsonJacksonMapCodec.

If I wrap the LocalDate in another object like an ArrayList, it is being serialized with @class and deserializing properly. But, just LocalDate is throwing exception and there is @class or any information about LocalDate for it to use while deserializing it.

Am I missing something? Any help would be greatly appreciated.