springboot中@Aysnc注解使用

1、在springboot启动类上添加@EnableAsync

@SpringBootApplication
@EnableConfigurationProperties
@EnableAsync
public class Main {

    public static final Logger logger = LoggerFactory.getLogger(Main.class);

    public static void main(String[] args) {
        logger.info("Spring Boot Beginning ...");
        SpringApplication.run(Main.class, args);
    }
}

2、在需要异步开启线程执行方法上添加@Aysnc注解

@Async
public void threadMethod() {
	log.info("********** hello world start **********");
	try {
		log.info("**********");
	} catch (Exception e) {
		log.error("hello java 异常");
	}
}

3、可以配置@Async的线程配置

默认情况下核心线程数CorePoolSize为1，最大线程数是int的最大值，可以定义配置类来实现AsyncConfigurer 接口，自定义线程池的配置；

@Component
public class MyAsyncConfigurer implements AsyncConfigurer {
    private static final Logger log = LoggerFactory.getLogger(MyAsyncConfigurer.class);

    @Override
    public Executor getAsyncExecutor() {
        ThreadPoolTaskExecutor threadPool = new ThreadPoolTaskExecutor();
        //设置核心线程数，默认为1
        threadPool.setCorePoolSize(1);  
        // 当核心线程都在跑任务，还有多余的任务会存到此处。
        threadPool.setQueueCapacity(100);
        //最大线程数，默认为Integer.MAX_VALUE，如果queueCapacity存满了，还有任务就会启动更多的线程，直到线程数达到maxPoolSize。如果还有任务，则根据拒绝策略进行处理。
        threadPool.setMaxPoolSize(1);  
        threadPool.setWaitForTasksToCompleteOnShutdown(true);  
        threadPool.setAwaitTerminationSeconds(60 * 15);  
        threadPool.setThreadNamePrefix("MyAsync-");
        threadPool.initialize();
        return threadPool;  
    }

}