SpringBoot使用@Async异步任务并合并结果集案例

一、基础任务类

@Component
public class AsyncCheckRuleBaseTask {

    @Async
    public Future task1() throws InterruptedException {
        System.out.println("task1任务开始");
        long currentTimeMillis = System.currentTimeMillis();
        int sum = 0;
        for (int i = 1; i <= 10000; i++) {
            sum += i;
        }
        Thread.sleep(1000);
        long currentTimeMillis1 = System.currentTimeMillis();
        System.out.println("task1任务耗时:"+(currentTimeMillis1-currentTimeMillis)+"ms");
        return new AsyncResult<>(sum);
    }

    @Async
    public Future task2() throws InterruptedException {
        System.out.println("task2任务开始");
        long currentTimeMillis = System.currentTimeMillis();
        int sum = 0;
        for (int i = 1; i <= 20000; i++) {
            sum += i;
        }
        Thread.sleep(2000);
        long currentTimeMillis1 = System.currentTimeMillis();
        System.out.println("task2任务耗时:"+(currentTimeMillis1-currentTimeMillis)+"ms");
        return new AsyncResult<>(sum);
    }

    @Async
    public Future task3() throws InterruptedException {
        System.out.println("task3任务开始");
        long currentTimeMillis = System.currentTimeMillis();
        int sum = 0;
        for (int i = 1; i <= 30000; i++) {
            sum += i;
        }
        Thread.sleep(3000);
        long currentTimeMillis1 = System.currentTimeMillis();
        System.out.println("task3任务耗时:"+(currentTimeMillis1-currentTimeMillis)+"ms");
        return new AsyncResult<>(sum);
    }
}

二、任务调用类 

@Service
public class AsyncCheckRuleTaskService {

    @Autowired
    AsyncCheckRuleBaseTask asyncCheckRuleBaseTask;

    public List doAllTask() throws InterruptedException, ExecutionException {
        long currentTimeMillis = System.currentTimeMillis();
        List list=new ArrayList<>();
        Future integerFuture1 = asyncCheckRuleBaseTask.task1();
        Future integerFuture2 = asyncCheckRuleBaseTask.task2();
        Future integerFuture3 = asyncCheckRuleBaseTask.task3();
        //获取异步任务的处理结果，异步任务没有处理完成，会一直阻塞，可以设置超时时间，使用 get 的重载方法
        list.add(integerFuture1.get());
        list.add(integerFuture2.get());
        list.add(integerFuture3.get());
        long currentTimeMillis1 = System.currentTimeMillis();
        System.out.println("task任务总耗时:"+(currentTimeMillis1-currentTimeMillis)+"ms");
        return list;
    }
}

三、测试类 

@RestController
@RequestMapping("/ruleCheckTask")
public class RuleCheckTaskController {

    @Autowired
    AsyncCheckRuleTaskService asyncCheckRuleTaskService;

    @PostMapping("/test")
    public ResponseMsg> check(@RequestBody RequestMsg in) throws InterruptedException, ExecutionException {
        ResponseMsg> response = new ResponseMsg<>();
        List integers = asyncCheckRuleTaskService.doAllTask();
        response.setData(integers);
        response.setHead(ResponseHead.buildSuccessHead());
        return response;
    }
}

四、测试结果

没开异步任务前至少需要：【task任务总耗时:6000ms】

开启以后：【task任务总耗时:3000+ms】

结果如下图：

五、可以自定义异步线程池

public class ContextCopyingDecorator implements TaskDecorator {
    //把context传递到线程中
    @Override
    public Runnable decorate(Runnable runnable) {
        RequestAttributes context = RequestContextHolder.currentRequestAttributes();
        return () -> {
            try {
                RequestContextHolder.setRequestAttributes(context);
                runnable.run();
            } finally {
                RequestContextHolder.resetRequestAttributes();
            }
        };
    }
}

@Configuration
@EnableAsync
public class AsyncThreadPoolConfig {
    /**
     * 获取当前机器CPU数量
     */
    private static final int CPU = Runtime.getRuntime().availableProcessors();
    /**
     * 核心线程数（默认线程数）
     */
    private static final int CORE_POOL_SIZE = CPU;
    /**
     * 最大线程数
     */
    private static final int MAX_POOL_SIZE = CPU * 2;
    /**
     * 允许线程空闲时间（单位：默认为秒）
     */
    private static final int KEEP_ALIVE_TIME = 60;
    /**
     * 缓冲队列数
     */
    private static final int QUEUE_CAPACITY = 200;
    /**
     * 线程池名前缀
     */
    private static final String THREAD_NAME_PREFIX = "ruleTaskExecutor-";

    /**
     * 注入自定义ruleTaskExecutor线程池
     * @return
     */
    @Bean("taskExecutor")
    public ThreadPoolTaskExecutor taskExecutor(){
        ThreadPoolTaskExecutor executor = new ThreadPoolTaskExecutor();
        executor.setTaskDecorator(new ContextCopyingDecorator());
        executor.setCorePoolSize(CORE_POOL_SIZE);
        executor.setMaxPoolSize(MAX_POOL_SIZE);
        executor.setQueueCapacity(QUEUE_CAPACITY);
        executor.setKeepAliveSeconds(KEEP_ALIVE_TIME);
        executor.setThreadNamePrefix(THREAD_NAME_PREFIX);
        // 线程池对拒绝任务的处理策略
        executor.setRejectedExecutionHandler(new ThreadPoolExecutor.CallerRunsPolicy());
        // 初始化
        executor.initialize();
        return executor;
    }
}