详解Spring缓存注解@Cacheable,@CachePut , @CacheEvict使用

@Cacheable(value="accountCache")// 使用了一个缓存名叫 accountCache 
public Account getAccountByName(String userName) {
   // 方法内部实现不考虑缓存逻辑，直接实现业务
   System.out.println("real query account."+userName); 
   return getFromDB(userName); 
} 

@CachePut(value="accountCache",key="#account.getName()")// 更新accountCache 缓存
public Account updateAccount(Account account) { 
  return updateDB(account); 
} 

@CacheEvict(value="accountCache",key="#account.getName()")// 清空accountCache 缓存 
public void updateAccount(Account account) {
   updateDB(account); 
} 

@CacheEvict(value="accountCache",allEntries=true)// 清空accountCache 缓存
public void reload() {
   reloadAll()
}

@Cacheable(value="accountCache",condition="#userName.length() <=4")// 缓存名叫 accountCache 
public Account getAccountByName(String userName) { 
 // 方法内部实现不考虑缓存逻辑，直接实现业务
 return getFromDB(userName); 
}

@CacheConfig("books")
public class BookRepositoryImpl implements BookRepository {

  @Cacheable
  public Book findBook(ISBN isbn) {...}
}

//@Cacheable将在执行方法之前( #result还拿不到返回值)判断condition，如果返回true，则查缓存； 
@Cacheable(value = "user", key = "#id", condition = "#id lt 10")
public User conditionFindById(final Long id) 

//@CachePut将在执行完方法后（#result就能拿到返回值了）判断condition，如果返回true，则放入缓存； 
@CachePut(value = "user", key = "#id", condition = "#result.username ne 'zhang'") 
public User conditionSave(final User user)  

//@CachePut将在执行完方法后（#result就能拿到返回值了）判断unless，如果返回false，则放入缓存；（即跟condition相反）
@CachePut(value = "user", key = "#user.id", unless = "#result.username eq 'zhang'")
public User conditionSave2(final User user)  

//@CacheEvict， beforeInvocation=false表示在方法执行之后调用（#result能拿到返回值了）；且判断condition，如果返回true，则移除缓存；
@CacheEvict(value = "user", key = "#user.id", beforeInvocation = false, condition = "#result.username ne 'zhang'") 
public User conditionDelete(final User user)  

@Caching(put = {
@CachePut(value = "user", key = "#user.id"),
@CachePut(value = "user", key = "#user.username"),
@CachePut(value = "user", key = "#user.email")
})
public User save(User user) {

@Caching(put = {
@CachePut(value = "user", key = "#user.id"),
@CachePut(value = "user", key = "#user.username"),
@CachePut(value = "user", key = "#user.email")
})
@Target({ElementType.METHOD, ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@Inherited
public @interface UserSaveCache {
}

@UserSaveCache
public User save(User user)

@Caching(
  cacheable = {
    @Cacheable(value = "user", key = "#username")
  },
  put = {
    @CachePut(value = "user", key = "#result.id", condition = "#result != null"),
    @CachePut(value = "user", key = "#result.email", condition = "#result != null")
  }
)
public User findByUsername(final String username) {
  System.out.println("cache miss, invoke find by username, username:" + username);
  for (User user : users) {
    if (user.getUsername().equals(username)) {
      return user;
    }
  }
  return null;
}

@CachePut(value="cacheName", key="#user.username", cacheValue="#user.username") 
public void save(User user)  


@Cacheable(value="cacheName", key="#user.username", cacheValue="#caches[0].get(#caches[0].get(#username).get())") 
public User findByUsername(String username) 

@CacheEvict(value = "user", key = "#user.id", condition = "#root.target.canCache() and #root.caches[0].get(#user.id).get().username ne #user.username", beforeInvocation = true) 
public void conditionUpdate(User user)