如何在Spring MVC 3中使用Servlet 3 @WebServlet&async？

import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebServlet(name = "MyAsyncServlet", urlPatterns = "/async", asyncSupported = true)
public class MyAsyncServlet extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws IOException {
        // 启动异步处理
        AsyncContext asyncContext = request.startAsync();

        // 获取异步上下文中的请求和响应对象
        HttpServletRequest asyncRequest = (HttpServletRequest) asyncContext.getRequest();
        HttpServletResponse asyncResponse = (HttpServletResponse) asyncContext.getResponse();

        // 在异步线程中执行耗时操作
        new Thread(() -> {
            try {
                // 模拟耗时操作
                Thread.sleep(5000);

                // 在异步线程中处理请求和响应
                asyncResponse.setContentType("text/plain");
                asyncResponse.getWriter().println("Async processing completed.");

                // 完成异步处理
                asyncContext.complete();
            } catch (InterruptedException | IOException e) {
                e.printStackTrace();
            }
        }).start();
    }
}

import org.springframework.boot.web.servlet.ServletRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

@Configuration
public class ServletConfig {
    @Bean
    public ServletRegistrationBean<MyAsyncServlet> myAsyncServlet() {
        ServletRegistrationBean<MyAsyncServlet> registrationBean = new ServletRegistrationBean<>();
        registrationBean.setServlet(new MyAsyncServlet());
        registrationBean.addUrlMappings("/async");
        return registrationBean;
    }
}