Spring Boot预加载数据到Redis。

Spring Boot 启动时预加载数据库数据到 Redis

在 Spring Boot 应用中，将数据库数据预加载到 Redis 缓存可以显著提升系统性能，减少数据库访问压力。下面介绍几种实现方式，包括代码示例和详细说明。

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使用 ApplicationRunner 或 CommandLineRunner

Spring Boot 提供了 ApplicationRunner 和 CommandLineRunner 接口，允许在应用启动后执行特定逻辑。这两种方式适合预加载数据到 Redis。

实现 ApplicationRunner

import org.springframework.boot.ApplicationArguments;
import org.springframework.boot.ApplicationRunner;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;

@Component
public class RedisDataLoader implements ApplicationRunner {

    private final RedisTemplate<String, Object> redisTemplate;
    private final UserRepository userRepository;

    public RedisDataLoader(RedisTemplate<String, Object> redisTemplate, UserRepository userRepository) {
        this.redisTemplate = redisTemplate;
        this.userRepository = userRepository;
    }

    @Override
    public void run(ApplicationArguments args) {
        List<User> users = userRepository.findAll();
        users.forEach(user -> {
            String key = "user:" + user.getId();
            redisTemplate.opsForValue().set(key, user);
        });
        System.out.println("Loaded " + users.size() + " users into Redis");
    }
}

实现 CommandLineRunner

import org.springframework.boot.CommandLineRunner;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;

@Component
public class RedisDataLoader implements CommandLineRunner {

    private final RedisTemplate<String, Object> redisTemplate;
    private final ProductRepository productRepository;

    public RedisDataLoader(RedisTemplate<String, Object> redisTemplate, ProductRepository productRepository) {
        this.redisTemplate = redisTemplate;
        this.productRepository = productRepository;
    }

    @Override
    public void run(String... args) {
        List<Product> products = productRepository.findAll();
        products.forEach(product -> {
            String key = "product:" + product.getId();
            redisTemplate.opsForValue().set(key, product