How to read data from Redis cache and query it in Java?

Question

I am new to redis cache i am using core or plain java not spring boot to interact with redis cache. I am able to connect to redis cache using the jedis client but not getting how to retrieve the data using combination of two keys i found a way in spring boot like below but i am unable to find the same in plain java please point me some source where i am unable to find any instructions in redis documentation also around this

@Cacheable(value = "items", key = "#id")
public Item getItem(Integer id) {
    Item item = itemRepository.findById(id).orElseThrow(RuntimeException::new);
    logger.info("Loading data from DB {}", item);
    return item;
}

Answer 1

On plain java, create a RedisTemplate object and then, use it to query your information.

public JedisConnectionFactory jedisConnectionFactory() {
    RedisStandaloneConfiguration config = new RedisStandaloneConfiguration(host, port);
    config.setUsername(username);
    config.setPassword(password);
    config.setDatabase(db);
    return new JedisConnectionFactory(config);
}


public RedisTemplate<?, ?> redisTemplate() {
    RedisTemplate<?, ?> template = new RedisTemplate<>();
    template.setConnectionFactory(jedisConnectionFactory());
    template.setKeySerializer(new GenericToStringSerializer<String>(String.class));
    template.setValueSerializer(new GenericJackson2JsonRedisSerializer());
    return template;
}

For example

redisTemplate.opsForValue().add("key", "value")