Nacos+@RefreshScope使用场景

Nacos+@RefreshScope使用场景

线程池配置动态刷新

Nacos的yaml配置

• 以下配置对应TaskExecutionProperties，为Spring自带配置类。使用@ConfigurationProperties注解的properties配置类会自动刷新

spring:
  task:
    execution:
      pool:
        core-size: 30
        max-size: 100
        queue-capacity: 0
      thread-name-prefix: async-task-

java配置类

• @RefreshScope放在@Bean这里，如果放在Class上面无效
• TaskExecutionProperties需要通过方法参数或者@Autowired的形式都会自动获取新配置

@Configuration
@EnableAsync
public class TaskExecutionConfig {

    @Bean
    @RefreshScope
    public ThreadPoolTaskExecutor asyncExecutor(TaskExecutionProperties springTaskExecutorProperties) {
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setCorePoolSize(springTaskExecutorProperties.getPool().getCoreSize());
        executor.setMaxPoolSize(springTaskExecutorProperties.getPool().getMaxSize());
        executor.setQueueCapacity(springTaskExecutorProperties.getPool().getQueueCapacity());
        // rejection-policy：当pool已经达到max size的时候，如何处理新任务
        // CALLER_RUNS：不在新线程中执行任务，而是有调用者所在的线程来执行
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.AbortPolicy());
        executor.initialize();
        return executor;
    }
}

Nacos配置中心修改配置，ThreadPoolTaskExecutor会重新加载实例化一个Bean

参考

• 线程池配置
• Nacos+@RefreshScope动态刷新配置源码解析