Spring-MVC 비동기 요청 Servlet 비동기 처리

public interface AsyncContext {
  String ASYNC_REQUEST_URI = "javax.servlet.async.request_uri";
  String ASYNC_CONTEXT_PATH = "javax.servlet.async.context_path";
  String ASYNC_PATH_INFO = "javax.servlet.async.path_info";
  String ASYNC_SERVLET_PATH = "javax.servlet.async.servlet_path";
  String ASYNC_QUERY_STRING = "javax.servlet.async.query_string";
  ServletRequest getRequest();
  ServletResponse getResponse();
  boolean hasOriginalRequestAndResponse();
  void dispatch();
  void dispatch(String var1);
  void dispatch(ServletContext var1, String var2);
  void complete();
  void start(Runnable var1);
  void addListener(AsyncListener var1);
  void addListener(AsyncListener var1, ServletRequest var2, ServletResponse var3);
  <T extends AsyncListener> T createListener(Class<T> var1) throws ServletException;
  void setTimeout(long var1);
  long getTimeout();
}

@WebServlet(
name = “WorkServlet”,
urlPatterns = “/work”,
asyncSupported = true
)
public class WorkServlet extends HttpServlet {
private static final long serialVersionUID =1L;

@Override
protected void doGet(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  this.doPost(req, resp);
}

@Override
protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
  //  ContentType,    
  resp.setContentType("text/plain;charset=UTF-8");
  resp.setHeader("Cache-Control","private");
  resp.setHeader("Pragma","no-cache");
  final PrintWriter writer= resp.getWriter();
  writer.println("       ");
  writer.flush();
  List<String> zuoyes=new ArrayList<String>();
  for (int i = 0; i < 10; i++) {
    zuoyes.add("zuoye"+i);;
  }
  final AsyncContext ac=req.startAsync();//      
  doZuoye(ac,zuoyes);
  writer.println("      ");
  writer.flush();
}

private void doZuoye(final AsyncContext ac, final List<String> zuoyes) {
  ac.setTimeout(1*60*60*1000L);
  ac.start(new Runnable() {
    @Override
    public void run() {
      //  response       
      try {
        PrintWriter writer=ac.getResponse().getWriter();
        for (String zuoye:zuoyes) {
          writer.println("\""+zuoye+"\"     ");
          Thread.sleep(1*1000L);
          writer.flush();
        }
        ac.complete();
      } catch (Exception e) {
        e.printStackTrace();
      }
    }
  });
}

public class TeacherListener implements AsyncListener {
  final SimpleDateFormat formatter=new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
  @Override
  public void onComplete(AsyncEvent event) throws IOException {
    System.out.println(" "+formatter.format(new Date())+"      ");
  }

  @Override
  public void onTimeout(AsyncEvent event) throws IOException {
    System.out.println(" "+formatter.format(new Date())+"    ");
  }

  @Override
  public void onError(AsyncEvent event) throws IOException {
    System.out.println(" "+formatter.format(new Date())+"      ");
  }

  @Override
  public void onStartAsync(AsyncEvent event) throws IOException {
    System.out.println(" "+formatter.format(new Date())+"      ");
  }
}

<servlet>
  <servlet-name>springmvc</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <init-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>/WEB-INF/applicationContext-mvc.xml</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
  <!--        -->
  <async-supported>true</async-supported>
</servlet>
<servlet-mapping>
  <servlet-name>springmvc</servlet-name>
  <url-pattern>/</url-pattern>
</servlet-mapping>

  @RequestMapping("/callable")
  public Callable<String> forCallable(Model model) throws Exception {
    return () -> {
      TimeUnit.SECONDS.sleep(1);//  1 ，        
      model.addAttribute("a", "aaaaaaa");
      return "async_request_callable";
    };
  }

 @RequestMapping("/callable/timeout")
  public WebAsyncTask<String> forCallableWithTimeout(Model model) throws Exception {
    long timeout = 5 * 1000L;
    WebAsyncTask<String> asyncTask = new WebAsyncTask<>(timeout, () -> {
      TimeUnit.MILLISECONDS.sleep(timeout + 10);
      model.addAttribute("a", "aaaaaaa");
      return "async_request_callable";
    });
    asyncTask.onTimeout(() -> {
      System.out.println("      ");
      return "async_request_callable_timeout";
    });
    asyncTask.onCompletion(() -> {
      System.out.println("  callable       ");
    });
    return asyncTask;
  }

@RequestMapping("/deferredresult")
public DeferredResult<String> forDeferredResult() throws Exception {
  DeferredResult<String> result = new DeferredResult<>();
  new Thread(() -> {
    try {
      TimeUnit.SECONDS.sleep(2);
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
    result.setResult("async_request_deferredresult");
  }).start();
  return result;
}

@RequestMapping("/deferredresult/timeout")
public DeferredResult<String> forDeferredResultWithTimeout() throws Exception {
  DeferredResult<String> result = new DeferredResult<>(10 * 1000);
  new Thread(() -> {
    try {
      TimeUnit.SECONDS.sleep(31);
    } catch (InterruptedException e) {
      e.printStackTrace();
    }
    result.setResult("async_request_deferredresult");
  }).start();
  
  result.onTimeout(() -> {
    System.out.println("        ");
  });
  
  result.onCompletion(() -> {
    System.out.println("         ");
  });
  
  return result;
}

<mvc:annotation-driven>
  <mvc:async-support default-timeout="15000" task-executor="asyncTaskExecutor"/>
</mvc:annotation-driven>

public interface CallableProcessingInterceptor { 
	static final Object RESULT_NONE = new Object(); 
	static final Object RESPONSE_HANDLED = new Object();
 
	/**
	 * Invoked <em>before</em> the start of concurrent handling in the original
	 * thread in which the {@code Callable} is submitted for concurrent handling.
	 *
	 * <p>
	 * This is useful for capturing the state of the current thread just prior to
	 * invoking the {@link Callable}. Once the state is captured, it can then be
	 * transferred to the new {@link Thread} in
	 * {@link #preProcess(NativeWebRequest, Callable)}. Capturing the state of
	 * Spring Security's SecurityContextHolder and migrating it to the new Thread
	 * is a concrete example of where this is useful.
	 * </p>
	 *
	 * @param request the current request
	 * @param task the task for the current async request
	 * @throws Exception in case of errors
	 */
	<T> void beforeConcurrentHandling(NativeWebRequest request, Callable<T> task) throws Exception;
 
	/**
	 * Invoked <em>after</em> the start of concurrent handling in the async
	 * thread in which the {@code Callable} is executed and <em>before</em> the
	 * actual invocation of the {@code Callable}.
	 *
	 * @param request the current request
	 * @param task the task for the current async request
	 * @throws Exception in case of errors
	 */
	<T> void preProcess(NativeWebRequest request, Callable<T> task) throws Exception;
 
	/**
	 * Invoked <em>after</em> the {@code Callable} has produced a result in the
	 * async thread in which the {@code Callable} is executed. This method may
	 * be invoked later than {@code afterTimeout} or {@code afterCompletion}
	 * depending on when the {@code Callable} finishes processing.
	 *
	 * @param request the current request
	 * @param task the task for the current async request
	 * @param concurrentResult the result of concurrent processing, which could
	 * be a {@link Throwable} if the {@code Callable} raised an exception
	 * @throws Exception in case of errors
	 */
	<T> void postProcess(NativeWebRequest request, Callable<T> task, Object concurrentResult) throws Exception;
 
	/**
	 * Invoked from a container thread when the async request times out before
	 * the {@code Callable} task completes. Implementations may return a value,
	 * including an {@link Exception}, to use instead of the value the
	 * {@link Callable} did not return in time.
	 *
	 * @param request the current request
	 * @param task the task for the current async request
	 * @return a concurrent result value; if the value is anything other than
	 * {@link #RESULT_NONE} or {@link #RESPONSE_HANDLED}, concurrent processing
	 * is resumed and subsequent interceptors are not invoked
	 * @throws Exception in case of errors
	 */
	<T> Object handleTimeout(NativeWebRequest request, Callable<T> task) throws Exception;
 
	/**
	 * Invoked from a container thread when async processing completes for any
	 * reason including timeout or network error.
	 *
	 * @param request the current request
	 * @param task the task for the current async request
	 * @throws Exception in case of errors
	 */
	<T> void afterCompletion(NativeWebRequest request, Callable<T> task) throws Exception;
 
}

<mvc:annotation-driven>
  <mvc:async-support default-timeout="15000" task-executor="asyncTaskExecutor">
    <mvc:callable-interceptors>
      <bean class="YourCallableProcessingInterceptor"/>
    </mvc:callable-interceptors>
  </mvc:async-support>
</mvc:annotation-driven>

public interface DeferredResultProcessingInterceptor {
 
	/**
	 * Invoked immediately before the start of concurrent handling, in the same
	 * thread that started it. This method may be used to capture state just prior
	 * to the start of concurrent processing with the given {@code DeferredResult}.
	 *
	 * @param request the current request
	 * @param deferredResult the DeferredResult for the current request
	 * @throws Exception in case of errors
	 */
	<T> void beforeConcurrentHandling(NativeWebRequest request, DeferredResult<T> deferredResult) throws Exception;
 
	/**
	 * Invoked immediately after the start of concurrent handling, in the same
	 * thread that started it. This method may be used to detect the start of
	 * concurrent processing with the given {@code DeferredResult}.
	 *
	 * <p>The {@code DeferredResult} may have already been set, for example at
	 * the time of its creation or by another thread.
	 *
	 * @param request the current request
	 * @param deferredResult the DeferredResult for the current request
	 * @throws Exception in case of errors
	 */
	<T> void preProcess(NativeWebRequest request, DeferredResult<T> deferredResult) throws Exception;
 
	/**
	 * Invoked after a {@code DeferredResult} has been set, via
	 * {@link DeferredResult#setResult(Object)} or
	 * {@link DeferredResult#setErrorResult(Object)}, and is also ready to
	 * handle the concurrent result.
	 *
	 * <p>This method may also be invoked after a timeout when the
	 * {@code DeferredResult} was created with a constructor accepting a default
	 * timeout result.
	 *
	 * @param request the current request
	 * @param deferredResult the DeferredResult for the current request
	 * @param concurrentResult the result to which the {@code DeferredResult}
	 * @throws Exception in case of errors
	 */
	<T> void postProcess(NativeWebRequest request, DeferredResult<T> deferredResult, Object concurrentResult) throws Exception;
 
	/**
	 * Invoked from a container thread when an async request times out before
	 * the {@code DeferredResult} has been set. Implementations may invoke
	 * {@link DeferredResult#setResult(Object) setResult} or
	 * {@link DeferredResult#setErrorResult(Object) setErrorResult} to resume processing.
	 *
	 * @param request the current request
	 * @param deferredResult the DeferredResult for the current request; if the
	 * {@code DeferredResult} is set, then concurrent processing is resumed and
	 * subsequent interceptors are not invoked
	 * @return {@code true} if processing should continue, or {@code false} if
	 * other interceptors should not be invoked
	 * @throws Exception in case of errors
	 */
	<T> boolean handleTimeout(NativeWebRequest request, DeferredResult<T> deferredResult) throws Exception;
 
	/**
	 * Invoked from a container thread when an async request completed for any
	 * reason including timeout and network error. This method is useful for
	 * detecting that a {@code DeferredResult} instance is no longer usable.
	 *
	 * @param request the current request
	 * @param deferredResult the DeferredResult for the current request
	 * @throws Exception in case of errors
	 */
	<T> void afterCompletion(NativeWebRequest request, DeferredResult<T> deferredResult) throws Exception;
 
}

<mvc:annotation-driven>
  <mvc:async-support default-timeout="15000" task-executor="asyncTaskExecutor">
    <mvc:deferred-result-interceptors>
      <bean class="YourDeferredResultProcessingInterceptor"/>
    </mvc:deferred-result-interceptors>
  </mvc:async-support>
</mvc:annotation-driven>