Spring Cache_spring cache 缓存介绍图

作者：我家自动化 | 2024-07-04 02:00:39

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spring cache 缓存介绍图

一、自定义缓存实现

1、缓存类

/**
* 缓存类
* @param <T>
*/
public class CacheManager<T> {

   private Map<String,T> cache = new ConcurrentHashMap<String,T>();

   /*
   * 缓存取值
   */
   public T getValue(Object key) {
       return cache.get(key);
   }

   /*
   * 存、更新缓存
   */
   public void addOrUpdateCache(String key,T value) {
       cache.put(key, value);
   }

   /**
   * 根据key删除缓存中的一条记录
   * @param key
   */
   public void evictCache(String key) {
       if(cache.containsKey(key)) {
           cache.remove(key);
       }
   }

   /*
   * 清空缓存中的记录
   */
   public void evictCache() {
       cache.clear();
   }
}

2、使用

@Service
public class UserService {

   private CacheManager<UserEntity> cacheManager;

   @Autowired
   private StudentRepository studentRepository;

   public UserService() {
       cacheManager = new CacheManager<UserEntity>();
   }

   public UserEntity findByID(Long id) {
       UserEntity user = cacheManager.getValue(id.toString());
       if(user != null) {
           System.out.println("缓存中取值...");
           return user;
       }
       Optional<UserEntity> userEntitys = studentRepository.findById(id);
       user = userEntitys.get();
       if(user != null) {
           System.out.println("走查询了...");
           cacheManager.addOrUpdateCache(id.toString(), user);
       }

       return user;
   }
}