詳解SpringBoot中異步請求和異步調(diào)用(看完這一篇就夠了)

@RequestMapping(value = "/email/servletReq", method = GET)
 public void servletReq (HttpServletRequest request, HttpServletResponse response) {
  AsyncContext asyncContext = request.startAsync();
  //設(shè)置監(jiān)聽器:可設(shè)置其開始、完成、異常、超時等事件的回調(diào)處理
 asyncContext.addListener(new AsyncListener() {
   @Override
   public void onTimeout(AsyncEvent event) throws IOException {
    System.out.println("超時了...");
    //做一些超時后的相關(guān)操作...
   }
   @Override
   public void onStartAsync(AsyncEvent event) throws IOException {
    System.out.println("線程開始");
   }
   @Override
   public void onError(AsyncEvent event) throws IOException {
    System.out.println("發(fā)生錯誤："+event.getThrowable());
   }
   @Override
   public void onComplete(AsyncEvent event) throws IOException {
    System.out.println("執(zhí)行完成");
    //這里可以做一些清理資源的操作...
   }
  });
  //設(shè)置超時時間
  asyncContext.setTimeout(20000);
  asyncContext.start(new Runnable() {
   @Override
   public void run() {
    try {
     Thread.sleep(10000);
     System.out.println("內(nèi)部線程：" + Thread.currentThread().getName());
     asyncContext.getResponse().setCharacterEncoding("utf-8");
     asyncContext.getResponse().setContentType("text/html;charset=UTF-8");
     asyncContext.getResponse().getWriter().println("這是異步的請求返回");
    } catch (Exception e) {
     System.out.println("異常："+e);
    }
    //異步請求完成通知
    //此時整個請求才完成
    asyncContext.complete();
   }
  });
  //此時之類 request的線程連接已經(jīng)釋放了
  System.out.println("主線程：" + Thread.currentThread().getName());
 }

@RequestMapping(value = "/email/callableReq", method = GET)
 @ResponseBody
 public Callable<String> callableReq () {
  System.out.println("外部線程：" + Thread.currentThread().getName());
  return new Callable<String>() {
   @Override
   public String call() throws Exception {
    Thread.sleep(10000);
    System.out.println("內(nèi)部線程：" + Thread.currentThread().getName());
    return "callable!";
   }
  };
 }
 @Configuration
 public class RequestAsyncPoolConfig extends WebMvcConfigurerAdapter {
 @Resource
 private ThreadPoolTaskExecutor myThreadPoolTaskExecutor;
 @Override
 public void configureAsyncSupport(final AsyncSupportConfigurer configurer) {
  //處理 callable超時
  configurer.setDefaultTimeout(60*1000);
  configurer.setTaskExecutor(myThreadPoolTaskExecutor);
  configurer.registerCallableInterceptors(timeoutCallableProcessingInterceptor());
 }
 @Bean
 public TimeoutCallableProcessingInterceptor timeoutCallableProcessingInterceptor() {
  return new TimeoutCallableProcessingInterceptor();
 }
}

@RequestMapping(value = "/email/webAsyncReq", method = GET)
@ResponseBody
public WebAsyncTask<String> webAsyncReq () {
 System.out.println("外部線程：" + Thread.currentThread().getName());
 Callable<String> result = () -> {
  System.out.println("內(nèi)部線程開始：" + Thread.currentThread().getName());
  try {
   TimeUnit.SECONDS.sleep(4);
  } catch (Exception e) {
   // TODO: handle exception
  }
  logger.info("副線程返回");
  System.out.println("內(nèi)部線程返回：" + Thread.currentThread().getName());
  return "success";
 };
 WebAsyncTask<String> wat = new WebAsyncTask<String>(3000L, result);
 wat.onTimeout(new Callable<String>() {

  @Override
  public String call() throws Exception {
   // TODO Auto-generated method stub
   return "超時";
  }
 });
 return wat;
}

@RequestMapping(value = "/email/deferredResultReq", method = GET)
@ResponseBody
public DeferredResult<String> deferredResultReq () {
 System.out.println("外部線程：" + Thread.currentThread().getName());
 //設(shè)置超時時間
 DeferredResult<String> result = new DeferredResult<String>(60*1000L);
 //處理超時事件 采用委托機制
 result.onTimeout(new Runnable() {

  @Override
  public void run() {
   System.out.println("DeferredResult超時");
   result.setResult("超時了!");
  }
 });
 result.onCompletion(new Runnable() {

  @Override
  public void run() {
   //完成后
   System.out.println("調(diào)用完成");
  }
 });
 myThreadPoolTaskExecutor.execute(new Runnable() {

  @Override
  public void run() {
   //處理業(yè)務(wù)邏輯
   System.out.println("內(nèi)部線程：" + Thread.currentThread().getName());
   //返回結(jié)果
   result.setResult("DeferredResult!!");
  }
 });
 return result;
}

@Controller
@RequestMapping("/app")
public class EmailController {
 //獲取ApplicationContext對象方式有多種,這種最簡單,其它的大家自行了解一下
 @Autowired
 private ApplicationContext applicationContext;
 
  @RequestMapping(value = "/email/asyncCall", method = GET)
  @ResponseBody
  public Map<String, Object> asyncCall () {
    Map<String, Object> resMap = new HashMap<String, Object>();
    try{
  //這樣調(diào)用同類下的異步方法是不起作用的
      //this.testAsyncTask();
  //通過上下文獲取自己的代理對象調(diào)用異步方法
   EmailController emailController = (EmailController)applicationContext.getBean(EmailController.class);
   emailController.testAsyncTask();
      resMap.put("code",200);
    }catch (Exception e) {
  resMap.put("code",400);
      logger.error("error!",e);
    }
    return resMap;
  }
 //注意一定是public,且是非static方法
 @Async
  public void testAsyncTask() throws InterruptedException {
    Thread.sleep(10000);
    System.out.println("異步任務(wù)執(zhí)行完成！");
  }
}

@Service
@Transactional(value = "transactionManager", readOnly = false, propagation = Propagation.REQUIRED, rollbackFor = Throwable.class)
public class EmailService {
  @Autowired
  private ApplicationContext applicationContext;
  @Async
  public void testSyncTask() throws InterruptedException {
    Thread.sleep(10000);
    System.out.println("異步任務(wù)執(zhí)行完成！");
  }
  public void asyncCallTwo() throws InterruptedException {
    //this.testSyncTask();
//    EmailService emailService = (EmailService)applicationContext.getBean(EmailService.class);
//    emailService.testSyncTask();
    boolean isAop = AopUtils.isAopProxy(EmailController.class);//是否是代理對象；
    boolean isCglib = AopUtils.isCglibProxy(EmailController.class); //是否是CGLIB方式的代理對象；
    boolean isJdk = AopUtils.isJdkDynamicProxy(EmailController.class); //是否是JDK動態(tài)代理方式的代理對象；
    //以下才是重點!!!
 EmailService emailService = (EmailService)applicationContext.getBean(EmailService.class);
    EmailService proxy = (EmailService) AopContext.currentProxy();
    System.out.println(emailService == proxy ? true : false);
    proxy.testSyncTask();
    System.out.println("end!!!");
  }
}