一篇文章搞懂SpringBoot整合Redis,通过注解实现缓存功能。

1.Docker环境下安装Redis5.0

1.1下载Redis5.0的Docker镜像

docker pull redis:5.0

1.2使用Docker命令启动Redis容器

docker run -p 6379:6379 --name redis -v /mydata/redis/data:/data -d redis:5.0 redis-server --appendonly yes

2.Spring Cache操作Redis

2.1常用注解

  • @EnableCaching :开启缓存功能,一般放在启动类上。
  • @Cacheable :使用该注解的方法当缓存时,不执行方法从缓存中获取数据,当缓存不存在时,执行方法将返回结果存入缓存,一般使用在查询方法上,可设置如下属性:
    value:缓存名称(必填),指定缓存的命名空间;
    key:用于设置在命名空间中的缓存key值,可以使用SpEL表达式定义;
    unless:条件符合则不缓存;
    condition:条件符合则缓存。
  • @CachePut :使用该注解的方法每次执行时都会把结果存入缓存中,一般用在新增方法上,可以设置如下属性;
    value:缓存名称(必填),指定缓存的命名空间;
    key:用于设置在命名空间中的缓存key值,可以使用SpEL表达式定义;
    unless:条件符合则不缓存;
    condition:条件符合则缓存。
  • @CacheEvict 使用该注解的方法执行时会清空指定的缓存,一般使用在更新或删除方法上,可以设置如下属性:
    value:缓存名称(必填),指定缓存的命名空间;
    key:用于设置在命名空间中的缓存key值,可以使用SpEL表达式定义;
    condition:条件符合则缓存。

2.2使用步骤


<dependency>
    <groupId>org.springframework.bootgroupId>
    <artifactId>spring-boot-starter-data-redisartifactId>
dependency>
  • 在pom.xml中添加项目依赖:
spring:
  redis:
    host:192.168.6.139# Redis服务器地址
    database:0# Redis数据库索引(默认为0)
    port:6379# Redis服务器连接端口
    password:# Redis服务器连接密码(默认为空)
    timeout:1000ms# 连接超时时间
  • 在启动类上添加@EnableCaching注解启动缓存功能;
@EnableCaching
@SpringBootApplication
publicclass MallTinyApplication {

    public static void main(String[] args) {
        SpringApplication.run(MallTinyApplication.class, args);
    }
}
  • 接下来在PmsBrandServiceImpl类中使用相关注解来实现缓存功能,可以发现我们获取品牌详情的方法中使用了@Cacheable注解,在修改和删除品牌的方法上使用了@CacheEvict注解;
/**
 * PmsBrandService实现类
 * Created by macro on 2019/4/19.
 */
@Service
publicclass PmsBrandServiceImpl implements PmsBrandService {
    @Autowired
    private PmsBrandMapper brandMapper;

    @CacheEvict(value = RedisConfig.REDIS_KEY_DATABASE, key = "'pms:brand:'+#id")
    @Override
    public int update(Long id, PmsBrand brand) {
        brand.setId(id);
        return brandMapper.updateByPrimaryKeySelective(brand);
    }

    @CacheEvict(value = RedisConfig.REDIS_KEY_DATABASE, key = "'pms:brand:'+#id")
    @Override
    public int delete(Long id) {
        return brandMapper.deleteByPrimaryKey(id);
    }

    @Cacheable(value = RedisConfig.REDIS_KEY_DATABASE, key = "'pms:brand:'+#id", unless = "#result==null")
    @Override
    public PmsBrand getItem(Long id) {
        return brandMapper.selectByPrimaryKey(id);
    }
}
  • 我们可以通过给RedisTemplate设置JSON格式的序列化器,并通过配置RedisCacheConfiguration设置超时时间来实现以上需求,此时别忘了去除启动类上的@EnableCaching注解,具体配置类RedisConfig代码如下;
 /**
 * Redis配置类
 * Created by macro on 2020/3/2.
 */
@EnableCaching
@Configuration
publicclass RedisConfig extends CachingConfigurerSupport {

    /**
     * redis数据库自定义key
     */
    publicstaticfinal String REDIS_KEY_DATABASE="mall";

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

    @Bean
    public RedisSerializer<Object> redisSerializer() {
        //创建JSON序列化器
        Jackson2JsonRedisSerializer<Object> serializer = new Jackson2JsonRedisSerializer<>(Object.class);
        ObjectMapper objectMapper = new ObjectMapper();
        objectMapper.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
        objectMapper.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);
        serializer.setObjectMapper(objectMapper);
        return serializer;
    }

    @Bean
    public RedisCacheManager redisCacheManager(RedisConnectionFactory redisConnectionFactory) {
        RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisConnectionFactory);
        //设置Redis缓存有效期为1天
        RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
                .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer())).entryTtl(Duration.ofDays(1));
        returnnew RedisCacheManager(redisCacheWriter, redisCacheConfiguration);
    }

}

3.使用Redis连接池

SpringBoot 2.x版本中默认客户端是用Lettuce实现的,Lettuce是一种可伸缩,线程安全,完全非阻塞的Redis客户端,多个线程可以共享一个RedisConnection,它利用Netty NIO框架来高效地管理多个连接,从而提供了异步和同步数据访问方式,用于构建非阻塞的反应性应用程序。

3.1使用步骤:

  • 修改application.yml添加Lettuce连接池配置,用于配置线程数量和阻塞等待时间;
 spring:
  redis:
    lettuce:
      pool:
        max-active:8# 连接池最大连接数
        max-idle:8# 连接池最大空闲连接数
        min-idle:0# 连接池最小空闲连接数
        max-wait:-1ms# 连接池最大阻塞等待时间,负值表示没有限制
  • 由于SpringBoot 2.x中默认并没有使用Redis连接池,所以需要在pom.xml中添加commons-pool2的依赖;
<dependency>
    <groupId>org.apache.commonsgroupId>
    <artifactId>commons-pool2artifactId>
dependency>

4.自由操作Redis

  • Spring Cache给我们提供了操作Redis缓存的便捷方法,但是也有很多局限性。比如说我们想单独设置一个缓存值的有效期怎么办?我们并不想缓存方法的返回值,我们想缓存方法中产生的中间值怎么办?此时我们就需要用到RedisTemplate这个类了,接下来我们来讲下如何,通过RedisTemplate来自由操作Redis中的缓存。

4.1定义Redis操作业务类

  • 在Redis中有几种数据结构,比如普通结构(对象),Hash结构、Set结构、List结构,该接口中定义了大多数常用操作方法。
 /**
 * redis操作Service
 * Created by macro on 2020/3/3.
 */
publicinterface RedisService {
    /**
     * 保存属性
     */
    void set(String key, Object value, long time);
    /**
     * 保存属性
     */
    void set(String key, Object value);
    /**
     * 获取属性
     */
    Object get(String key);
    /**
     * 删除属性
     */
    Boolean del(String key);
    /**
     * 批量删除属性
     */
    Long del(List<String> keys);
    /**
     * 设置过期时间
     */
    Boolean expire(String key, long time);
    /**
     * 获取过期时间
     */
    Long getExpire(String key);
    /**
     * 判断是否有该属性
     */
    Boolean hasKey(String key);
    /**
     * 按delta递增
     */
    Long incr(String key, long delta);
    /**
     * 按delta递减
     */
    Long decr(String key, long delta);
    /**
     * 获取Hash结构中的属性
     */
    Object hGet(String key, String hashKey);
    /**
     * 向Hash结构中放入一个属性
     */
    Boolean hSet(String key, String hashKey, Object value, long time);
    /**
     * 向Hash结构中放入一个属性
     */
    void hSet(String key, String hashKey, Object value);
    /**
     * 直接获取整个Hash结构
     */
    Map<Object, Object> hGetAll(String key);
    /**
     * 直接设置整个Hash结构
     */
    Boolean hSetAll(String key, Map<String, Object> map, long time);
    /**
     * 直接设置整个Hash结构
     */
    void hSetAll(String key, Map<String, Object> map);
    /**
     * 删除Hash结构中的属性
     */
    void hDel(String key, Object... hashKey);
    /**
     * 判断Hash结构中是否有该属性
     */
    Boolean hHasKey(String key, String hashKey);
    /**
     * Hash结构中属性递增
     */
    Long hIncr(String key, String hashKey, Long delta);
    /**
     * Hash结构中属性递减
     */
    Long hDecr(String key, String hashKey, Long delta);
    /**
     * 获取Set结构
     */
    Set<Object> sMembers(String key);
    /**
     * 向Set结构中添加属性
     */
    Long sAdd(String key, Object... values);
    /**
     * 向Set结构中添加属性
     */
    Long sAdd(String key, long time, Object... values);
    /**
     * 是否为Set中的属性
     */
    Boolean sIsMember(String key, Object value);
    /**
     * 获取Set结构的长度
     */
    Long sSize(String key);
    /**
     * 删除Set结构中的属性
     */
    Long sRemove(String key, Object... values);
    /**
     * 获取List结构中的属性
     */
    List<Object> lRange(String key, long start, long end);
    /**
     * 获取List结构的长度
     */
    Long lSize(String key);
    /**
     * 根据索引获取List中的属性
     */
    Object lIndex(String key, long index);
    /**
     * 向List结构中添加属性
     */
    Long lPush(String key, Object value);
    /**
     * 向List结构中添加属性
     */
    Long lPush(String key, Object value, long time);
    /**
     * 向List结构中批量添加属性
     */
    Long lPushAll(String key, Object... values);
    /**
     * 向List结构中批量添加属性
     */
    Long lPushAll(String key, Long time, Object... values);
    /**
     * 从List结构中移除属性
     */
    Long lRemove(String key, long count, Object value);
}
  • RedisServiceImpl
    RedisService的实现类,使用RedisTemplate来自由操作Redis中的缓存数据。
/**
 * redis操作实现类
 * Created by macro on 2020/3/3.
 */
@Service
publicclass RedisServiceImpl implements RedisService {
    @Autowired
    private RedisTemplate<String, Object> redisTemplate;

    @Override
    public void set(String key, Object value, long time) {
        redisTemplate.opsForValue().set(key, value, time, TimeUnit.SECONDS);
    }

    @Override
    public void set(String key, Object value) {
        redisTemplate.opsForValue().set(key, value);
    }

    @Override
    public Object get(String key) {
        return redisTemplate.opsForValue().get(key);
    }

    @Override
    public Boolean del(String key) {
        return redisTemplate.delete(key);
    }

    @Override
    public Long del(List<String> keys) {
        return redisTemplate.delete(keys);
    }

    @Override
    public Boolean expire(String key, long time) {
        return redisTemplate.expire(key, time, TimeUnit.SECONDS);
    }

    @Override
    public Long getExpire(String key) {
        return redisTemplate.getExpire(key, TimeUnit.SECONDS);
    }

    @Override
    public Boolean hasKey(String key) {
        return redisTemplate.hasKey(key);
    }

    @Override
    public Long incr(String key, long delta) {
        return redisTemplate.opsForValue().increment(key, delta);
    }

    @Override
    public Long decr(String key, long delta) {
        return redisTemplate.opsForValue().increment(key, -delta);
    }

    @Override
    public Object hGet(String key, String hashKey) {
        return redisTemplate.opsForHash().get(key, hashKey);
    }

    @Override
    public Boolean hSet(String key, String hashKey, Object value, long time) {
        redisTemplate.opsForHash().put(key, hashKey, value);
        return expire(key, time);
    }

    @Override
    public void hSet(String key, String hashKey, Object value) {
        redisTemplate.opsForHash().put(key, hashKey, value);
    }

    @Override
    public Map<Object, Object> hGetAll(String key) {
        return redisTemplate.opsForHash().entries(key);
    }

    @Override
    public Boolean hSetAll(String key, Map<String, Object> map, long time) {
        redisTemplate.opsForHash().putAll(key, map);
        return expire(key, time);
    }

    @Override
    public void hSetAll(String key, Map<String, Object> map) {
        redisTemplate.opsForHash().putAll(key, map);
    }

    @Override
    public void hDel(String key, Object... hashKey) {
        redisTemplate.opsForHash().delete(key, hashKey);
    }

    @Override
    public Boolean hHasKey(String key, String hashKey) {
        return redisTemplate.opsForHash().hasKey(key, hashKey);
    }

    @Override
    public Long hIncr(String key, String hashKey, Long delta) {
        return redisTemplate.opsForHash().increment(key, hashKey, delta);
    }

    @Override
    public Long hDecr(String key, String hashKey, Long delta) {
        return redisTemplate.opsForHash().increment(key, hashKey, -delta);
    }

    @Override
    public Set<Object> sMembers(String key) {
        return redisTemplate.opsForSet().members(key);
    }

    @Override
    public Long sAdd(String key, Object... values) {
        return redisTemplate.opsForSet().add(key, values);
    }

    @Override
    public Long sAdd(String key, long time, Object... values) {
        Long count = redisTemplate.opsForSet().add(key, values);
        expire(key, time);
        return count;
    }

    @Override
    public Boolean sIsMember(String key, Object value) {
        return redisTemplate.opsForSet().isMember(key, value);
    }

    @Override
    public Long sSize(String key) {
        return redisTemplate.opsForSet().size(key);
    }

    @Override
    public Long sRemove(String key, Object... values) {
        return redisTemplate.opsForSet().remove(key, values);
    }

    @Override
    public List<Object> lRange(String key, long start, long end) {
        return redisTemplate.opsForList().range(key, start, end);
    }

    @Override
    public Long lSize(String key) {
        return redisTemplate.opsForList().size(key);
    }

    @Override
    public Object lIndex(String key, long index) {
        return redisTemplate.opsForList().index(key, index);
    }

    @Override
    public Long lPush(String key, Object value) {
        return redisTemplate.opsForList().rightPush(key, value);
    }

    @Override
    public Long lPush(String key, Object value, long time) {
        Long index = redisTemplate.opsForList().rightPush(key, value);
        expire(key, time);
        return index;
    }

    @Override
    public Long lPushAll(String key, Object... values) {
        return redisTemplate.opsForList().rightPushAll(key, values);
    }

    @Override
    public Long lPushAll(String key, Long time, Object... values) {
        Long count = redisTemplate.opsForList().rightPushAll(key, values);
        expire(key, time);
        return count;
    }

    @Override
    public Long lRemove(String key, long count, Object value) {
        return redisTemplate.opsForList().remove(key, count, value);
    }
}

  • 测试RedisService中缓存操作的Controller
/**
 * Redis测试Controller
 * Created by macro on 2020/3/3.
 */
@Api(tags = "RedisController", description = "Redis测试")
@Controller
@RequestMapping("/redis")
publicclass RedisController {
    @Autowired
    private RedisService redisService;
    @Autowired
    private PmsBrandService brandService;

    @ApiOperation("测试简单缓存")
    @RequestMapping(value = "/simpleTest", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult<PmsBrand> simpleTest() {
        List<PmsBrand> brandList = brandService.list(1, 5);
        PmsBrand brand = brandList.get(0);
        String key = "redis:simple:" + brand.getId();
        redisService.set(key, brand);
        PmsBrand cacheBrand = (PmsBrand) redisService.get(key);
        return CommonResult.success(cacheBrand);
    }

    @ApiOperation("测试Hash结构的缓存")
    @RequestMapping(value = "/hashTest", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult<PmsBrand> hashTest() {
        List<PmsBrand> brandList = brandService.list(1, 5);
        PmsBrand brand = brandList.get(0);
        String key = "redis:hash:" + brand.getId();
        Map<String, Object> value = BeanUtil.beanToMap(brand);
        redisService.hSetAll(key, value);
        Map<Object, Object> cacheValue = redisService.hGetAll(key);
        PmsBrand cacheBrand = BeanUtil.mapToBean(cacheValue, PmsBrand.class, true);
        return CommonResult.success(cacheBrand);
    }

    @ApiOperation("测试Set结构的缓存")
    @RequestMapping(value = "/setTest", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult<Set<Object>> setTest() {
        List<PmsBrand> brandList = brandService.list(1, 5);
        String key = "redis:set:all";
        redisService.sAdd(key, (Object[]) ArrayUtil.toArray(brandList, PmsBrand.class));
        redisService.sRemove(key, brandList.get(0));
        Set<Object> cachedBrandList = redisService.sMembers(key);
        return CommonResult.success(cachedBrandList);
    }

    @ApiOperation("测试List结构的缓存")
    @RequestMapping(value = "/listTest", method = RequestMethod.GET)
    @ResponseBody
    public CommonResult<List<Object>> listTest() {
        List<PmsBrand> brandList = brandService.list(1, 5);
        String key = "redis:list:all";
        redisService.lPushAll(key, (Object[]) ArrayUtil.toArray(brandList, PmsBrand.class));
        redisService.lRemove(key, 1, brandList.get(0));
        List<Object> cachedBrandList = redisService.lRange(key, 0, 3);
        return CommonResult.success(cachedBrandList);
    }
}

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