mybatis+springboot整合redis实现缓存查询（解决@Cacheable默认为二进制格式）

Bertha 。 2021-08-30 02:37 571阅读 0赞

## 1.导入依赖 ##

<dependencies>
            <dependency>
                <groupId>org.mybatis</groupId>
                <artifactId>mybatis</artifactId>
                <version>3.5.3</version>
            </dependency>
            
            <dependency>
                <groupId>org.mybatis.spring.boot</groupId>
                <artifactId>mybatis-spring-boot-starter</artifactId>
                <version>1.3.2</version>
            </dependency>
            <dependency>
                <groupId>mysql</groupId>
                <artifactId>mysql-connector-java</artifactId>
                <scope>runtime</scope>
            </dependency>
            
            <dependency>
                <groupId>com.alibaba</groupId>
                <artifactId>fastjson</artifactId>
                <version>1.2.58</version>
            </dependency>
            
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-data-redis</artifactId>
            </dependency>
    
    
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-web</artifactId>
            </dependency>
    
            <dependency>
                <groupId>org.projectlombok</groupId>
                <artifactId>lombok</artifactId>
                <optional>true</optional>
            </dependency>
            <dependency>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-test</artifactId>
                <scope>test</scope>
                <exclusions>
                    <exclusion>
                        <groupId>org.junit.vintage</groupId>
                        <artifactId>junit-vintage-engine</artifactId>
                    </exclusion>
                </exclusions>
            </dependency>
        </dependencies>

#添加项目名
    server.servlet.context-path=/redis
    server.port=80
    
    
    #数据库连接信息（useUnicode=true&characterEncoding=UTF-8不加中文查询不到）
    spring.datasource.driver-class-name=com.mysql.cj.jdbc.Driver
    spring.datasource.password=root
    spring.datasource.username=root
    spring.datasource.url=jdbc:mysql://127.0.0.1:3306/cloud?serverTimezone=UTC&useUnicode=true&characterEncoding=UTF-8
    
    #配置mybatis
    #别名扫描包
    mybatis.type-aliases-package=com.dxf.redis.pojo
    mybatis.mapper-locations=classpath:mapper/*Mapper.xml
    
    
    #redis配置
    #Redis服务器地址
    spring.redis.host=127.0.0.1
    #Redis服务器连接端口
    spring.redis.port=6379
    spring.redis.password=myroot
    #Redis数据库索引（默认为0）
    spring.redis.database=0  
    #连接池最大连接数（使用负值表示没有限制）
    spring.redis.jedis.pool.max-active=50
    #连接池最大阻塞等待时间（使用负值表示没有限制）
    spring.redis.jedis.pool.max-wait=3000
    #连接池中的最大空闲连接
    spring.redis.jedis.pool.max-idle=20
    #连接池中的最小空闲连接
    spring.redis.jedis.pool.min-idle=2
    #连接超时时间（毫秒）
    spring.redis.timeout=5000
    
    logging.level.com.dxf.redis.mapper:debug

## 2.RedisConfig ##

**在此省略mapper和实体类  
//注意实体类实现序列化**  
**public class User implements Serializable \{**

@Configuration
    @EnableCaching //开启spring缓存注解
    public class RedisConfig  extends CachingConfigurerSupport { 
    
        /** * 自定义生成key的规则 */
        @Override
        public KeyGenerator keyGenerator() { 
            return new KeyGenerator() { 
                @Override
                public Object generate(Object o, Method method, Object... objects) { 
                    //格式化缓存key字符串
                    StringBuilder sb = new StringBuilder();
                    //追加类名
                    sb.append(o.getClass().getName());
                    //追加方法名
                    sb.append(method.getName());
                    //遍历参数并且追加
                    for (Object obj : objects) { 
                        sb.append(obj.toString());
                    }
                    System.out.println("调用Redis缓存Key : " + sb.toString());
                    return sb.toString();
                }
            };
        }
    
       /** * @Description: 使用@Cacheable注解的时候会将返回的对象缓存起来，默认缓存的值是二进制的， * 为此我们自定义序列化配置，改成JSON格式的 * @Auther: dxf * @Date: 20:31 2020/5/20 */
        @Bean
        public RedisCacheManager redisCacheManager(RedisTemplate redisTemplate) { 
            RedisCacheWriter redisCacheWriter = RedisCacheWriter.nonLockingRedisCacheWriter(redisTemplate.getConnectionFactory());
            RedisCacheConfiguration redisCacheConfiguration = RedisCacheConfiguration.defaultCacheConfig()
                    .entryTtl(Duration.ofHours(1))// 设置缓存有效期一小时
                    .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(redisTemplate.getValueSerializer()));
            return new RedisCacheManager(redisCacheWriter, redisCacheConfiguration);
        }
    
        /** *自己的RedisTemplate */
        @Bean
        public RedisTemplate<String, Object> redisTemplate(RedisConnectionFactory factory) { 
            RedisTemplate<String, Object> template = new RedisTemplate();
            template.setConnectionFactory(factory);
            //序列化配置
            Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);
            ObjectMapper om = new ObjectMapper();
            om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY);
            //om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL);过时
                    om.activateDefaultTyping(LaissezFaireSubTypeValidator.instance ,
                    ObjectMapper.DefaultTyping.NON_FINAL, JsonTypeInfo.As.PROPERTY);
            jackson2JsonRedisSerializer.setObjectMapper(om);
            //String的序列化
            StringRedisSerializer stringRedisSerializer = new StringRedisSerializer();
            // key采用String的序列化方式
            template.setKeySerializer(stringRedisSerializer);
            // hash的key也采用String的序列化方式
            template.setHashKeySerializer(stringRedisSerializer);
            // value序列化方式采用jackson
            template.setValueSerializer(jackson2JsonRedisSerializer);
            // hash的value序列化方式采用jackson
            template.setHashValueSerializer(jackson2JsonRedisSerializer);
            template.afterPropertiesSet();
            return template;
        }
    
    
    }

## 3.UserServiceImpl ##

**几个关键注解**

1,@Cacheable

标注在方法上, 将方法返回的结果存入缓存中

可以指定 cachename 或 value 来对 ConcurrentMapCache 的 name 属性进行设置

也可以通过指定 keyGenerator 来制定缓存键值对中生成 key 的规则

默认情况: name 为传入的参数, 键值对中的值为方法返回结果

2,@CachePut

标注在方法上, 先执行方法, 再用方法返回的值来更新缓存内容

3,@CacheEvict

清除缓存

4,@Caching

复杂的 cache 配置, 可以在里面配置上面的几个注解

5,@CacheConfig

标注在类上, 对类中的缓存操作作统一配置

@Service
    public class UserServiceImpl implements UserService { 
    
        @Resource
        UserMapper userMapper;
    
        @Cacheable(value = "user")
        @Override
        public User getUserById(Integer id) { 
            return userMapper.selectByPrimaryKey(id);
        }
    
        @Override
        public int insUser(User user) { 
            return userMapper.insertSelective(user);
        }
    
        @CacheEvict(value = "user",allEntries = true)
        @Override
        public int delUserById(Integer id) { 
            return userMapper.deleteByPrimaryKey(id);
        }
    
        @CacheEvict(value = "user",allEntries = true)
        @Override
        public int updUser(User user) { 
            return userMapper.updateByPrimaryKeySelective(user);
        }
    }

**成功**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjQwODY0OA_size_16_color_FFFFFF_t_70_pic_center]  
**查询已删除内容**  
![在这里插入图片描述][watermark_type_ZmFuZ3poZW5naGVpdGk_shadow_10_text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3dlaXhpbl80MjQwODY0OA_size_16_color_FFFFFF_t_70_pic_center 1]

## 4.修改版 ##

//@Cacheable(value = "user")
        @Cacheable(value = "user_details", key = "#id", unless="#result == null")
        @Override
        public User getUserById(Integer id) { 
            return userMapper.selectByPrimaryKey(id);
        }
    
        //@CacheEvict(value = "user",allEntries = true)
        @CacheEvict(value = "user_details", key = "#id")
        @Override
        public int delUserById(Integer id) { 
            return userMapper.deleteByPrimaryKey(id);
        }
    
        //@CacheEvict(value = "user",allEntries = true)
        @CachePut(value = "user_details", key = "#user.id")
        @Override
        public User updUser(User user) { 
            if(userMapper.updateByPrimaryKeySelective(user)> 0) { 
                //返回user填入缓存
                return userMapper.selectByPrimaryKey(user.getId());
            }else{ 
                return null;
            }
        }

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