Spring Boot+Mybatis Plus 使用Redis实现二级缓存具体步骤以及代码

非常感谢您的提问。以下是 Spring Boot Mybatis Plus 使用 Redis 实现二级缓存的具体步骤和代码：

1. 首先，在 pom.xml 文件中添加 Redis 相关依赖：

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<dependency>
    <groupId>com.baomidou</groupId>
    <artifactId>mybatis-plus-boot-starter</artifactId>
    <version>3.4.0</version>
</dependency>

2. 在 application.properties 文件中添加 Redis 相关配置：

spring.redis.host=127.0.0.1
spring.redis.port=6379
spring.redis.database=0
spring.redis.password=
spring.redis.timeout=3000
spring.redis.jedis.pool.max-active=8
spring.redis.jedis.pool.max-wait=-1
spring.redis.jedis.pool.max-idle=8
spring.redis.jedis.pool.min-idle=0

3. 在 Mybatis Plus 的配置文件中开启二级缓存，并配置 Redis 缓存：

@Configuration
@MapperScan("com.example.mapper")
public class MybatisPlusConfig {

    @Bean
    public ConfigurationCustomizer configurationCustomizer() {
        return new ConfigurationCustomizer() {
            @Override
            public void customize(Configuration configuration) {
                // 开启二级缓存
                configuration.setCacheEnabled(true);
                // 配置 Redis 缓存
                RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
                        .entryTtl(Duration.ofMinutes(30)); // 设置缓存过期时间为 30 分钟
                configuration.addCache(new RedisCache("mybatis-plus", new RedisCacheWriter() {
                    @Override
                    public void put(String key, byte[] value) {
                        redisTemplate().opsForValue().set(key, value, Duration.ofMinutes(30));
                    }

                    @Override
                    public byte[] get(String key) {
                        return redisTemplate().opsForValue().get(key);
                    }

                    @Override
                    public void put(String key, byte[] value, long time, TimeUnit unit) {
                        redisTemplate().opsForValue().set(key, value, Duration.ofMillis(unit.toMillis(time)));
                    }

                    @Override
                    public void delete(String key) {
                        redisTemplate().delete(key);
                    }

                    @Override
                    public void clean() {
                        redisTemplate().getConnectionFactory().getConnection().flushDb();
                    }

                    @Override
                    public long size() {
                        return redisTemplate().getConnectionFactory().getConnection().dbSize();
                    }
                }, redisCacheConfiguration));
            }
        };
    }

    @Bean
    public RedisTemplate<String, Object> redisTemplate() {
        RedisTemplate<String, Object> redisTemplate = new RedisTemplate<>();
        redisTemplate.setConnectionFactory(redisConnectionFactory());
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(new JdkSerializationRedisSerializer());
        redisTemplate.setHashKeySerializer(new StringRedisSerializer());
        redisTemplate.setHashValueSerializer(new JdkSerializationRedisSerializer());
        return redisTemplate;
    }

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        LettuceConnectionFactory lettuceConnectionFactory = new LettuceConnectionFactory();
        lettuceConnectionFactory.setHostName("127.0.0.1");
        lettuceConnectionFactory.setPort(6379);
        lettuceConnectionFactory.setPassword("");
        lettuceConnectionFactory.setDatabase(0);
        return lettuceConnectionFactory;
    }
}

4. 在需要使用二级缓存的 Mapper 中添加 @CacheNamespace 注解：

@CacheNamespace(implementation = MybatisRedisCache.class, eviction = MybatisRedisCache.class)
public interface UserMapper extends BaseMapper<User> {
    // ...
}

5. 最后，实现 MybatisRedisCache 类，继承自 RedisCache，重写 clear 方法：

public class MybatisRedisCache extends RedisCache {

    public MybatisRedisCache(String name, RedisCacheWriter cacheWriter, RedisCacheConfiguration configuration) {
        super(name, cacheWriter, configuration);
    }

    @Override
    public void clear() {
        RedisConnection connection = Objects.requireNonNull(getRedisCacheWriter().getRedisConnectionFactory().getConnection());
        connection.flushDb();
        connection.close();
    }
}

以上就是 Spring Boot Mybatis Plus 使用 Redis 实现二级缓存的具体步骤和代码。希望能对您有所帮助！