1.说明

在springboot 中使用 @Async 实现异步任务处理,下面介绍一下如何实现这个。

2.实现代码

2.1 增加@EnableAsync

@EnableAsync
public class Demo1Application {

public static void main(String[] args) {
SpringApplication.run(Demo1Application.class, args);
}

}

2.2 构造一个线程池

实现异步时,我们需要手工构造一个线程池,否则会出现内存泄漏的问题。

@Configuration
public class AsyncThreadPoolConfig {

private static final int MAX_POOL_SIZE = 20;
private static final int CORE_POOL_SIZE = 10;
private static final int TASK_NUM = 200;
private static final int ACTIVE_TIME = 60;

@Bean("myExecutor")
public AsyncTaskExecutor asyncTaskExecutor() {
ThreadPoolTaskExecutor asyncTaskExecutor = new ThreadPoolTaskExecutor();
asyncTaskExecutor.setMaxPoolSize(MAX_POOL_SIZE);
asyncTaskExecutor.setCorePoolSize(CORE_POOL_SIZE);
asyncTaskExecutor.setQueueCapacity(TASK_NUM);
asyncTaskExecutor.setKeepAliveSeconds(ACTIVE_TIME);
asyncTaskExecutor.setThreadNamePrefix("laozhang_");
asyncTaskExecutor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
asyncTaskExecutor.initialize();
return asyncTaskExecutor;
}

}

2.3 使用注解

@Component
public class AsyncTest {

@Async(value = "myExecutor")
public void longTime() throws InterruptedException {
System.err.println("----------------start----------------");
Thread.sleep(5000);
System.err.println("----------------end----------------");
}
}

增加一个@Async注解,表示这个方法会使用异步处理