Add item reader/writer for Redis

[fmbenhassine]

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Add support to read data from and write data to Redis based on Spring Data Redis.

Reference: https://stackoverflow.com/questions/24703753/does-spring-batch-have-a-redis-itemreader-in-the-roadmap

[santfirax]

Hello @benas, I would like to work on this. Any chance that you can provide some guidance ?

[fmbenhassine]

@santfirax Thank you for your offer to help! The writer could be based on KeyValueItemWriter for consistency with other key/value writers. For the reader, I need some time to reflect on the best way to read data from Redis (ie make the reader use a RedisTemplate or a Redis Repository). But I'm open to ideas, so you are welcome to open a PR and we can discuss it there.

[santfirax]

Hello @benas I've created a PR for the write using RedisTemplate. https://github.com/spring-projects/spring-batch/pull/3961. Any chance that you can take a look at it ?

[MinJunKweon]

Hello, @benas. I have an idea about RedisRepositoryItemReader / RedisRepositoryItemWriter. They are based on RedisRepository. So ItemReader can read data that saved by RedisRepository. And ItemWriter can write data through RedisRepository. I would like to open a PR for this. Is there anything I should know?

[seonWKim]

Hi, @fmbenhassine. I wonder if this issue is handled by anyone. If not, may I try on this issue?

[fmbenhassine]

This was resolved in 1bd0e0c. Thanks @santfirax for the PR!

For the item reader, please join the discussion in #4446.

[seonWKim]

@fmbenhassine Thank you! I'll join above discussion.