57. Spring Cache Redis项目第一次用缓存

使用步骤
测试：

缓存什么？
缓存数据字典！

使用步骤

1. pom

这里写在工具类中

<!-- redis -->
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-data-redis</artifactId>
</dependency>
<!-- spring2.X集成redis所需common-pool2-->
<dependency>
<groupId>org.apache.commons</groupId>
<artifactId>commons-pool2</artifactId>
<version>2.6.0</version>
</dependency>

2. yml

spring.redis.host=192.168.237.127
spring.redis.port=6379
spring.redis.database= 0
spring.redis.timeout=1800000
spring.redis.lettuce.pool.max-active=20
spring.redis.lettuce.pool.max-wait=-1
#最大阻塞等待时间(负数表示没限制)
spring.redis.lettuce.pool.max-idle=5
spring.redis.lettuce.pool.min-idle=0

3. redis配置类

（固定结构，不用修改。但要求能看懂！）

第一个方法：自定义key规则
第二个方法：设置RedisTemplate规则（不懂！）
第三个方法：设置CacheManager缓存规则（不懂！） ```java import com.fasterxml.jackson.annotation.JsonAutoDetect; import com.fasterxml.jackson.annotation.PropertyAccessor; import com.fasterxml.jackson.databind.ObjectMapper; import org.springframework.cache.CacheManager; import org.springframework.cache.annotation.EnableCaching; import org.springframework.cache.interceptor.KeyGenerator; import org.springframework.context.annotation.Bean; import org.springframework.context.annotation.Configuration; import org.springframework.data.redis.cache.RedisCacheConfiguration; import org.springframework.data.redis.cache.RedisCacheManager; import org.springframework.data.redis.connection.RedisConnectionFactory; import org.springframework.data.redis.core.RedisTemplate; import org.springframework.data.redis.serializer.Jackson2JsonRedisSerializer; import org.springframework.data.redis.serializer.RedisSerializationContext; import org.springframework.data.redis.serializer.RedisSerializer; import org.springframework.data.redis.serializer.StringRedisSerializer;

import java.lang.reflect.Method; import java.time.Duration;

@Configuration @EnableCaching public class RedisConfig {

/**
 * 自定义key规则
 * @return
 */
@Bean
public KeyGenerator keyGenerator() {
    return new KeyGenerator() {
        @Override
        public Object generate(Object target, Method method, Object... params) {
            StringBuilder sb = new StringBuilder();
            sb.append(target.getClass().getName());
            sb.append(method.getName());
            for (Object obj : params) {
                sb.append(obj.toString());
            }
            return sb.toString();
        }
    };
}
/**
 * 设置RedisTemplate规则
 * @param redisConnectionFactory
 * @return
 */
@Bean
public RedisTemplate<Object, Object> redisTemplate(RedisConnectionFactory redisConnectionFactory) {
    RedisTemplate<Object, Object> redisTemplate = new RedisTemplate<>();
    redisTemplate.setConnectionFactory(redisConnectionFactory);
    Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);

//解决查询缓存转换异常的问题 ObjectMapper om = new ObjectMapper(); // 指定要序列化的域，field,get和set,以及修饰符范围，ANY是都有包括private和public om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); // 指定序列化输入的类型，类必须是非final修饰的，final修饰的类，比如String,Integer等会跑出异常 om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om);

//序列号key value redisTemplate.setKeySerializer(new StringRedisSerializer()); redisTemplate.setValueSerializer(jackson2JsonRedisSerializer); redisTemplate.setHashKeySerializer(new StringRedisSerializer()); redisTemplate.setHashValueSerializer(jackson2JsonRedisSerializer);

    redisTemplate.afterPropertiesSet();
    return redisTemplate;
}
/**
 * 设置CacheManager缓存规则
 * @param factory
 * @return
 */
@Bean
public CacheManager cacheManager(RedisConnectionFactory factory) {
    RedisSerializer<String> redisSerializer = new StringRedisSerializer();
    Jackson2JsonRedisSerializer jackson2JsonRedisSerializer = new Jackson2JsonRedisSerializer(Object.class);

//解决查询缓存转换异常的问题 ObjectMapper om = new ObjectMapper(); om.setVisibility(PropertyAccessor.ALL, JsonAutoDetect.Visibility.ANY); om.enableDefaultTyping(ObjectMapper.DefaultTyping.NON_FINAL); jackson2JsonRedisSerializer.setObjectMapper(om);

// 配置序列化（解决乱码的问题）,过期时间600秒 RedisCacheConfiguration config = RedisCacheConfiguration.defaultCacheConfig() .entryTtl(Duration.ofSeconds(600)) .serializeKeysWith(RedisSerializationContext.SerializationPair.fromSerializer(redisSerializer)) .serializeValuesWith(RedisSerializationContext.SerializationPair.fromSerializer(jackson2JsonRedisSerializer)) .disableCachingNullValues();

    RedisCacheManager cacheManager = RedisCacheManager.builder(factory)
            .cacheDefaults(config)
            .build();
    return cacheManager;
}

} ```

4. 注解

位置？
在service的实现类上
项目中如何使用的？

@Cacheable(value = “dict”,keyGenerator = “keyGenerator”)

public List findChlidData(Long id) {}
这两个参数都是设置key的

@CacheEvict(value = “dict”, allEntries=true)

public void importDictData(MultipartFile file) {}

（1）@Cacheable

个人理解：类似代理服务器。。。

尚医通