Servlet 3.0 异步 不异步，错在哪里？

Question

package com.servlet;

import java.io.PrintWriter;
import java.util.Date;
import javax.servlet.AsyncContext;

/**
 *
 * @author Administrator
 */
public class ProcessTask implements Runnable{
    private AsyncContext ctx = null;
    public ProcessTask(AsyncContext ctx) {
        this.ctx = ctx;
    }
    
    @Override
    public void run() {
        try {
            //等待十秒钟，以模拟业务方法的执行
            Thread.sleep(1000);
            PrintWriter out = ctx.getResponse().getWriter();
            out.println("业务处理完毕的时间：" + new Date() + ".<br/>");
            out.flush();
            ctx.complete();
        } catch (Exception e) {
        }
    }
    
}


/*
 * To change this template, choose Tools | Templates
 * and open the template in the editor.
 */
package com.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import java.util.Date;
import javax.servlet.AsyncContext;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.annotation.WebServlet;

/**
 *
 * @author Administrator
 */
@WebServlet(asyncSupported=true,urlPatterns={"/async"} ,name="Async Server")
public class AsyncDemoServlet extends HttpServlet {

	private static final long serialVersionUID = 1L;

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

    @Override
    protected void doPost(HttpServletRequest req, HttpServletResponse resp) throws ServletException, IOException {
        process(req, resp);
    }
    
    protected void process(HttpServletRequest req, HttpServletResponse resp)throws ServletException, IOException {
        PrintWriter out = null;
        try {
            resp.setContentType("text/html;charset=UTF-8");
            out = resp.getWriter();
            out.println("进入Servlet的时间：" + new Date() + ".<br/>");
            out.flush();
            
            //在子线程中执行业务调用，并由其负责输出响应，主线程退出
            boolean asyncSupported = req.isAsyncStarted();
            out.println("是否支持异步：" + asyncSupported + ".<br/>");
            out.flush();
            if(asyncSupported){
                AsyncContext ctx = req.startAsync();
                ctx.start(new ProcessTask(ctx));
            }
            out.println("结束Servlet的时间：" + new Date() + ".<br/>");
            out.flush();
        } catch (IOException ex) {
        } finally {
            out.close();
        }
        
    }
}

其中一句  boolean asyncSupported = req.isAsyncStarted();
返回false。

其表示不支持 异步 吗？
测试容器为 Apache Tomcat/7.0.21， GlassFish Server 3.1.1

Answer 1

isAsyncStarted

根据方法名可以知道这个方法的主要目的是是否开始异步任务

asyncSupported

根据的变量名，我们可以知道，你需要的是，是否支持异步

聪明的小伙伴，你发现什么了吗？

Answer 2

楼主自己没注意，你调用的方法是isAynsStarted()，而调用的时候又是在req.startAysnc()方式之前.....楼主是意思应该是调用isAynsSupported()才对