002 spring boot redis demo

pom

        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>

添加@EnableCaching

@SpringBootApplication
@EnableCaching
public class SpringBootRedisApplication {
    public static void main(String[] args) {
        SpringApplication.run(SpringBootRedisApplication.class, args);
    }
}

RedisConfig

@Configuration
public class RedisConfig {

    @Bean
    public RedisConnectionFactory redisConnectionFactory() {
        // Lettuce是基于netty的nio redis客户端
        return new LettuceConnectionFactory("192.168.1.170", 6379);
    }

    @Bean
    public RedisTemplate redisTemplate() {
        RedisTemplate redisTemplate = new RedisTemplate();
        redisTemplate.setConnectionFactory(redisConnectionFactory());
        redisTemplate.setKeySerializer(new StringRedisSerializer());
        redisTemplate.setValueSerializer(new JdkSerializationRedisSerializer());
        return redisTemplate;
    }

    @Bean
    public CacheManager cacheManager() {
        RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory());
        RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig();
        return new RedisCacheManager(redisCacheWriter, redisCacheConfiguration);
    }

}

UserDto

public class UserDto implements Serializable {
    private String userId;
    private String userName;
	// 省略: 构造方法 get set toString

UserService

@Service
public class UserService {

    @Cacheable(cacheManager = "cacheManager", value = "cache-1", key = "#userId")
    public UserDto findUserById(String userId) throws Exception {
        // 读取数据库
        UserDto user = new UserDto(userId, "张三");
        System.out.println("从数据库中读取到数据：" + user);
        return user;
    }

    @CacheEvict(cacheManager = "cacheManager", value = "cache-1", key = "#userId")
    public void deleteUserById(String userId) throws Exception {
        System.out.println("用户从数据库删除成功，请检查缓存是否清除~~" + userId);
    }

    /**
     * 如果数据库更新成功，更新redis缓存
     *
     * @param user
     * @return
     * @throws Exception
     */
    @CachePut(cacheManager = "cacheManager", value = "cache-1", key = "#user.userId", condition = "#result ne null")
    public UserDto updateUser(UserDto user) throws Exception {
        // 读取数据库
        System.out.println("数据库进行了更新，检查缓存是否一致");
        // 返回最新内容，代表更新成功
        return user;
    }
}

单元测试

@RunWith(SpringRunner.class)
@SpringBootTest
public class SpringBootRedisApplicationTests {

    @Autowired
    private UserService userService;

    @Test
    public void testQuery() throws Exception {
        UserDto userDto = userService.findUserById("1");
        System.out.println(userDto);
    }

    @Test
    public void testUpdate() throws Exception {
        userService.updateUser(new UserDto("1", "李四"));
        testQuery();
    }

    @Test
    public void testRemove() throws Exception {
        userService.deleteUserById("1");
        System.out.println("请使用 `keys *` 命令检查 key `cache-1::1`是否还存在");
    }

}