Spring InitializingBean的使用方式

@Component
public class MyBean implements InitializingBean {
    private SomeService service;
    // 通过 @Autowired 或 setter 方法注入
    @Autowired
    public void setService(SomeService service) {
        this.service = service;
    }
    @Override
    public void afterPropertiesSet() throws Exception {
        // 确保所有依赖都已注入
        if (service == null) {
            throw new IllegalStateException("Service not injected!");
        }
        // 执行初始化逻辑
        service.initialize();
        // 数据预加载、缓存预热等
    }
}

<bean id="myBean" class="com.example.MyBean" 
      init-method="myInit">
    <!-- 属性配置 -->
</bean>

public class MyBean {
    public void myInit() {
        // 初始化逻辑
    }
}

@Component
public class MyBean {
    @PostConstruct
    public void init() {
        // 推荐使用这种方式
        // 更符合注解驱动的编程风格
        // 与 Spring 框架解耦
    }
}

@Bean(initMethod = "init")
public MyBean myBean() {
    return new MyBean();
}

@Service
public class CacheService implements InitializingBean {
    private Map<String, Object> cache;
    @Autowired
    private ConfigService configService;
    @Autowired
    private DataLoader dataLoader;
    @Override
    public void afterPropertiesSet() throws Exception {
        // 确保依赖注入完成
        Objects.requireNonNull(configService);
        Objects.requireNonNull(dataLoader);
        // 初始化缓存
        cache = new ConcurrentHashMap<>();
        // 预加载热点数据
        List<HotItem> hotItems = dataLoader.loadHotItems();
        hotItems.forEach(item -> 
            cache.put(item.getId(), item)
        );
        // 启动缓存刷新线程
        startRefreshThread();
    }
}