Redis缓存之自定义CacheManager

[y123132]

CacheManager===Cache 缓存组件来实际给缓存中存储数据
1，引入redis的starter，容器中保存的是RedisCacheManager
2，RedisCacheManager 帮我们创建RedisCache 来作为缓存组件；
RedisCache通过操作redis来缓存数据
3，默认保存数据 K -V 都是通过序列化来保存的；

关于能存储redis。第二次查不能反序列化出来的问题。
原因：存的是dept的缓存数据，而CacheManager默认使用RedisTemplate<Object, Employee>来操作redis
解决方法：
自定义CacheManager：
1> 引入了redis的starter，cacheManager变为RedisCacheManager
2> 默认创建的RedisCacheManager 操作redis的时候使用的是 RedisTemlate<Object，Object>
3> RedisTemlate<Object，Object> 是默认使用jdk序列化机制
4> 自定义CacheManager

@Configuration
public class MyRedisConfig {

    //员工缓存
    @Bean
    public RedisTemplate<Object, Employee> empRedisTemplate(RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
        RedisTemplate<Object, Employee> template = new RedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
        Jackson2JsonRedisSerializer<Employee> ser = new Jackson2JsonRedisSerializer<Employee>(Employee.class);
        template.setDefaultSerializer(ser);
        return template;
    }

    //员工缓存
    //CacheManagerCustomizers 可以定制缓存的一些规则
    @Bean
    @Primary  //默认缓存管理器  必须得有默认
    public RedisCacheManager employeeCacheManager(RedisTemplate<Object, Employee> empRedisTemplate) {
        RedisCacheManager cacheManager = new RedisCacheManager(empRedisTemplate);
        //key多了一个前缀

        //使用前缀，默认把cacheName作为前缀
        cacheManager.setUsePrefix(true);
        return cacheManager;
    }


    //部门缓存
    @Bean
    public RedisTemplate<Object, Department> deptRedisTemplate(RedisConnectionFactory redisConnectionFactory) throws UnknownHostException {
        RedisTemplate<Object, Department> template = new RedisTemplate();
        template.setConnectionFactory(redisConnectionFactory);
        Jackson2JsonRedisSerializer<Department> ser = new Jackson2JsonRedisSerializer<Department>(Department.class);
        template.setDefaultSerializer(ser);
        return template;
    }

    //部门缓存
    @Bean
    public RedisCacheManager deptCacheManager(RedisTemplate<Object, Department> deptRedisTemplate) {
        RedisCacheManager cacheManager = new RedisCacheManager(deptRedisTemplate);
        cacheManager.setUsePrefix(true);
        return cacheManager;
    }
}

1. @Primary 当自定义两个CacheManager的时候。必须指定一个为默认的
    
2. 针对不同的service可以直接标注CacheManager，同时如果有默认指定，可以省略不写

   @CacheConfig(cacheNames = "dept",cacheManager = "deptCacheManager")
   @Service
   public class DeptService {
   @CacheConfig(cacheNames = "emp"/*,cacheManager = "employeeCacheManager"*/)
   @Service
   public class EmployeeService {
   }
   ​​​​​​​}