#yyds干货盘点# springboot使用@Async实现异步调用

Posted 2022-01-06 灰太狼_cxh

springboot使用@Async实现异步调用

1.代码实现：

创建异步任务类

@Slf4j
@Component
public class AsyncTasks 

    public static Random random = new Random();

    @Async
    public CompletableFuture<String> doTaskOne() throws Exception 
        log.info("开始做任务一");
        long start = System.currentTimeMillis();
        Thread.sleep(random.nextInt(10000));
        long end = System.currentTimeMillis();
        log.info("完成任务一，耗时：" + (end - start) + "毫秒");
        return CompletableFuture.completedFuture("任务一完成");
    

    @Async
    public CompletableFuture<String> doTaskTwo() throws Exception 
        log.info("开始做任务二");
        long start = System.currentTimeMillis();
        Thread.sleep(random.nextInt(10000));
        long end = System.currentTimeMillis();
        log.info("完成任务二，耗时：" + (end - start) + "毫秒");
        return CompletableFuture.completedFuture("任务二完成");
    

    @Async
    public CompletableFuture<String> doTaskThree() throws Exception 
        log.info("开始做任务三");
        long start = System.currentTimeMillis();
        Thread.sleep(random.nextInt(10000));
        long end = System.currentTimeMillis();
        log.info("完成任务三，耗时：" + (end - start) + "毫秒");
        return CompletableFuture.completedFuture("任务三完成");
    

启动类添加异步注解

@EnableAsync
@SpringBootApplication
public class AsyncTaskApplication 

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

    

测试类

@Slf4j
@SpringBootTest
class AsyncTaskApplicationTests 

    @Autowired
    private AsyncTasks asyncTasks;

    @Test
    void contextLoads() 
    

    @Test
    public void Test() throws Exception 
        long start = System.currentTimeMillis();

        CompletableFuture<String> task1 = asyncTasks.doTaskOne();
        CompletableFuture<String> task2 = asyncTasks.doTaskTwo();
        CompletableFuture<String> task3 = asyncTasks.doTaskThree();

        CompletableFuture.allOf(task1, task2, task3).join();

        long end = System.currentTimeMillis();

        log.info("任务全部完成，总耗时：" + (end - start) + "毫秒");
    

2.实现效果：

2021-12-29 16:23:10.176  INFO 7500 --- [           main] c.c.a.AsyncTaskApplicationTests          : Started AsyncTaskApplicationTests in 1.054 seconds (JVM running for 3.159)
2021-12-29 16:23:10.613  INFO 7500 --- [         task-2] com.cxh.async_task.task.AsyncTasks       : 开始做任务二
2021-12-29 16:23:10.613  INFO 7500 --- [         task-1] com.cxh.async_task.task.AsyncTasks       : 开始做任务一
2021-12-29 16:23:10.614  INFO 7500 --- [         task-3] com.cxh.async_task.task.AsyncTasks       : 开始做任务三
2021-12-29 16:23:14.654  INFO 7500 --- [         task-2] com.cxh.async_task.task.AsyncTasks       : 完成任务二，耗时：4041毫秒
2021-12-29 16:23:15.138  INFO 7500 --- [         task-3] com.cxh.async_task.task.AsyncTasks       : 完成任务三，耗时：4524毫秒
2021-12-29 16:23:15.873  INFO 7500 --- [         task-1] com.cxh.async_task.task.AsyncTasks       : 完成任务一，耗时：5259毫秒
2021-12-29 16:23:15.874  INFO 7500 --- [           main] c.c.a.AsyncTaskApplicationTests          : 任务全部完成，总耗时：5320毫秒

可以看到，通过异步调用，让任务一、二、三并发执行，有效的减少了程序的总运行时间。