SpringCloud动态配置注解@RefreshScope与@Component的深度解析

import org.springframework.cloud.context.config.annotation.RefreshScope;
import org.springframework.stereotype.Component;
import org.springframework.beans.factory.annotation.Value;

@RefreshScope  // 启用动态刷新
@Component     // 注册为 Spring Bean
public class DynamicConfigService {

    @Value("${app.timeout:5000}")  // 默认值 5000ms
    private int timeout;

    public int getTimeout() {
        return timeout;
    }
}

app:
  timeout: 3000

POST http://localhost:8080/actuator/refresh

@RefreshScope
@Service
public class PaymentService {

    @Value("${payment.enabled:false}")
    private boolean enabled;

    public boolean isPaymentEnabled() {
        return enabled;
    }
}

@RefreshScope
@Configuration
public class AppConfig {

    @Bean
    @LoadBalanced  // 结合 Ribbon 使用
    public RestTemplate restTemplate() {
        return new RestTemplate();
    }
}

@RefreshScope  // 正确
// @Refreshscope  // 错误

<dependency>
    <groupId>org.springframework.cloud</groupId>
    <artifactId>spring-cloud-context</artifactId>
    <version>4.1.1</version>
</dependency>

import org.springframework.cloud.context.config.annotation.RefreshScope;  // 正确
// import org.springframework.context.annotation.Scope;  // 错误

@RefreshScope
@Component
public class CacheManager {

    @Value("${cache.size:100}")
    private int cacheSize;

    private Map<String, Object> cache;

    @PostConstruct
    public void init() {
        cache = new LRUCache(cacheSize);  // 刷新后重建缓存
    }
}

@RefreshScope
@Component
@ConfigurationProperties(prefix = "app")
public class AppProperties {
    private int timeout;
    private String name;

    // getters & setters
}

@Component
public class RefreshListener {

    @EventListener
    public void onRefresh(RefreshScopeRefreshedEvent event) {
        System.out.println("配置已刷新，Bean: " + event.getName());
    }
}