java - Spring Boot启动时加载数据到Ehcache 3

Question

我想在 Spring Boot 应用程序启动时加载缓存中的数据。我知道Ehcache2中有一种使用BootstrapCacheLoader的集成方式。 How to load data from database to Ehcache when the application starts但我在 Ehcache3 中没有看到这一点。我仍然可以在 @postConstruct 方法中手动完成此操作。但我想知道是否有一个集成的解决方案(Spring 5，Ehcache 3)

谢谢。

Answer 1

我最终在 Spring 上下文初始化后完成了这件事。对于 DB 集合中的每个元素，我调用具有 @Cacheable 注释的 getResourceById()，从而填充整个 DB 集合的缓存。

我不建议在 @PostConstruct 中运行此代码，因为代理可能尚未创建，并且 @Cacheable 等注释可能尚未工作。

在触发 ContextRefreshedEvent 事件时(初始化后或刷新后)运行此代码是加载缓存的更合适位置。

public class CacheLoader {

private final Logger logger = LoggerFactory.getLogger(CacheLoader.class);

@Autowired
private ResourcePermissionRepository resourcePermissionRepository;
@Autowired
private ResourcePermissionService resourcePermissionService;


@EventListener
public void onApplicationEvent(ContextRefreshedEvent event) {
    logger.info("Loading cache following start/refresh event");
    for (PermissionGroup permissionGroup : permissionGroupRepository.findAll()) {
        permissionGroupService.getGroupById(permissionGroup.getGroupName());
    }

    for(ResourcePermission resourcePermission: resourcePermissionRepository.findAll()) {
        resourcePermissionService.getResourceById(resourcePermission.getResourceId());
    }
    logger.info("Finished loading cache");
}


public class ResourcePermissionService {

private final Logger logger = LoggerFactory.getLogger(ResourcePermissionService.class);

@Autowired
private ResourcePermissionRepository resourcePermissionRepository;


@Cacheable(value = "resources", sync = true)
 public ResourcePermission getResourceById(String resourceId) {
    logger.info("Cache miss for resource " + resourceId);
    return resourcePermissionRepository.findById(resourceId).orElse(new NullResourcePermission());
}

@CachePut(value = "resources", key = "#result.resourceId")
public ResourcePermission addResourcePermission(ResourcePermission resourcePermission) {
    return resourcePermissionRepository.save(resourcePermission);
}

@CacheEvict(value = "resources")
public void deleteById(String resourceId) {
    resourcePermissionRepository.deleteById(resourceId);
}
}