[Today’s Coding] Step8. Backend - Redis Write-Through Caching processing

@RedisHash test

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Before testing...

Previously, through a database connection test, we confirmed that the connection to redis was good. If you need to check connections or dependencies, check the post below.

2023.02.26 - [Project/오늘의 코딩 서비스 프로그램] - [오늘의코딩] Step3. 데이터베이스 연결

In order to push data to Redis in advance, you must retrieve the data from MySQL and put it into Redis. At this time, each entity must be annotated with @RedisHash as shown below so that it can be integrated with Redis.

@Entity
@Table(name="CATEGORIES")
@RedisHash(value = "CATEGORIES")

To check Redis data push, I wrote a test code as shown below and confirmed that the data was entered correctly.

package com.toco.trialService.connectionTest;
import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
import com.toco.trialService.entity.Categories;
import com.toco.trialService.repository.CategoriesRepository;
import com.toco.trialService.repository.redis.CategoriesRedisRepository;
import io.lettuce.core.RedisClient;
import io.lettuce.core.api.StatefulRedisConnection;
import io.lettuce.core.api.sync.RedisCommands;
import org.junit.jupiter.api.AfterEach;
import org.junit.jupiter.api.BeforeEach;
import org.junit.jupiter.api.DisplayName;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.extension.ExtendWith;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.jdbc.AutoConfigureTestDatabase;
import org.springframework.boot.test.autoconfigure.orm.jpa.DataJpaTest;
import org.springframework.test.context.junit.jupiter.SpringExtension;
import java.util.List;
import static org.springframework.test.util.AssertionErrors.assertTrue;
@ExtendWith(SpringExtension.class)
@DataJpaTest
@DisplayName("Redis Push Test")
@AutoConfigureTestDatabase(replace = AutoConfigureTestDatabase.Replace.NONE)
public class RedisPushTest {
@Autowired
private CategoriesRepository categoriesRepository;
@Autowired
private CategoriesRedisRepository categoriesRedisRepository;
private RedisClient redisClient;
private StatefulRedisConnection connection;
private RedisCommands redisCommands;
@BeforeEach
public void beforeConnectDatabase(){
redisClient = RedisClient.create("redis://localhost:6379");
connection = redisClient.connect();
redisCommands = connection.sync();
}
@AfterEach
public void afterConnectDatabase(){
//redisCommands.expire("categories",10);
connection.close();
redisClient.shutdown();
}
@Test
public void redisPushTest() throws JsonProcessingException {
List categories = categoriesRepository.findAll();
categoriesRedisRepository.saveAll(categories);
assertTrue("TRUE", categories.equals(categoriesRedisRepository.findAll()));
}
}

In this code, the value was entered into Redis as an entity using @RedisHash.

During the testing process, I tried changing Object to String, but there was a problem with jackson-datatype deserialization. For those who want to input data as json, I have written a detailed solution in the post below. I hope this helps people experiencing the same problem.