Tomcat7实现Servlet3异步请求

pom.xml：

<dependency>      <groupId>javax.servlet</groupId>      <artifactId>javax.servlet-api</artifactId>      <version>3.0.1</version>        <scope>provided</scope>  </dependency>

web.xml：

<web-app version="3.0" xmlns="http://java.sun.com/xml/ns/javaee"     xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"   xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_3_0.xsd">   <display-name>Servlet3-Demo</display-name>  </web-app>

AsyncServlet：

@WebServlet(value = "/async-demo", asyncSupported = true)  public class AsyncServlet extends HttpServlet {     ScheduledThreadPoolExecutor executor = new ScheduledThreadPoolExecutor(2);     public void doGet(HttpServletRequest req, HttpServletResponse res) {    AsyncContext aCtx = req.startAsync(req, res);      executor.execute(new AsyncHandler(aCtx));   }    }

AsyncHandler：

public class AsyncHandler implements Runnable {     private AsyncContext ctx;     public AsyncHandler(AsyncContext ctx) {    this.ctx = ctx;   }     @Override   public void run() {    System.out.println("Dispatch Time: " + System.currentTimeMillis());      ctx.dispatch("/index.jsp");   }    }