1，开启异步线程，在启动类上加注解：

2，自定义线程池：

@Configuration
public class PromotionConfig {@Beanpublic Executor generateExchangeCodeExecutor() {ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();// 1.核心线程池大小executor.setCorePoolSize(2);// 2.最大线程池大小executor.setMaxPoolSize(5);// 3.队列大小executor.setQueueCapacity(200);// 4.线程名称executor.setThreadNamePrefix("exchange-code-handler-");// 5.拒绝策略executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());executor.initialize();return executor;}
}

3，使用线程池：