springmvc处理异步请求的示例

<web-app xmlns="http://java.sun.com/xml/ns/javaee"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
http://java.sun.com/xml/ns/javaee
http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd"
version="3.0">
...
</web-app>

<!-- springMVC的Servlet配置 -->
<servlet>
  <servlet-name>dispatcher</servlet-name>
  <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>
  <init-param>
    <param-name>contextConfigLocation</param-name>
    <param-value>classpath*:META-INF/dispatcher-context.xml</param-value>
  </init-param>
  <load-on-startup>1</load-on-startup>
  <async-supported>true</async-supported>
</servlet>

<!-- 编码拦截 -->
<filter>
  <filter-name>CharacterEncodingFilter</filter-name>
  <filter-class>org.springframework.web.filter.CharacterEncodingFilter</filter-class>
  <async-supported>true</async-supported>
  <init-param>
    <param-name>encoding</param-name>
    <param-value>UTF-8</param-value>
  </init-param>
  <init-param>
    <param-name>forceEncoding</param-name>
    <param-value>true</param-value>
  </init-param>
</filter>

@RequestMapping("/mvc25")
public Callable<String> mvc25() {

  return new Callable<String>() {
    @Override
    public String call() throws Exception {
       Thread.sleep(2000);
       return "task/task";
    }
  };

}

@RequestMapping("/mvc26")
@ResponseBody
public Callable<String> mvc26() {

  return new Callable<String>() {
    @Override
    public String call() throws Exception {
      Thread.sleep(2000);
      return "hello task";
    }
  };

}

@RequestMapping("/mvc27")
@ResponseBody
public WebAsyncTask<String> mvc27() {

  Callable<String> callable = new Callable<String>() {
    @Override
    public String call() throws Exception {
      Thread.sleep(10000);
      return "hello task";
    }
  };

  return new WebAsyncTask<String>(10000, callable);
}

@RequestMapping("/mvc28")
@ResponseBody
public Callable<String> mvc28() {

  Callable<String> callable = new Callable<String>() {
    @Override
    public String call() throws Exception {
      Thread.sleep(2000);
      throw new RuntimeException();
    }
  };

  return callable;

}

@ExceptionHandler(RuntimeException.class)
@ResponseBody
public JSONObject handlerException(){

  JSONObject jsonObject = new JSONObject();
  jsonObject.put("aaa", 123);

  return jsonObject ;
}

@RequestMapping("/mvc29")
@ResponseBody
public DeferredResult<String> mvc29() {

  DeferredResult<String> deferredResult = new DeferredResult<String>();
  dealInOtherThread(deferredResult);
  return deferredResult;

}

private void dealInOtherThread(DeferredResult<String> deferredResult) {
  try {
    Thread.sleep(2000);
  } catch (InterruptedException e) {
    // TODO Auto-generated catch block
    e.printStackTrace();
  }

  deferredResult.setResult("hello task");
}