javaee 测试http2 代码出错

Question

package com.servlet;

import java.io.IOException;
import java.io.PrintWriter;
import javax.servlet.ServletException;
import javax.servlet.annotation.HttpMethodConstraint;
import javax.servlet.annotation.ServletSecurity;
import static javax.servlet.annotation.ServletSecurity.TransportGuarantee.CONFIDENTIAL;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.PushBuilder;

/**
*

• @author hyl */ @WebServlet(name = "TestServlet", urlPatterns = {"/TestServlet"}) @ServletSecurity(httpMethodConstraints={ @HttpMethodConstraint(value="GET", transportGuarantee=CONFIDENTIAL) })

public class TestServlet extends HttpServlet {
@Override
protected void doGet(HttpServletRequest req, HttpServletResponse res)
throws IOException, ServletException {
PushBuilder pushBuilder = req.newPushBuilder().path("my.css");
pushBuilder.push();
res.getWriter().println("

HTTP2 TestHello");
}
}

运行结果是：
无法访问此网站 localhost 意外终止了连接。
请试试以下办法：

检查网络连接
检查代理服务器和防火墙
运行 Windows 网络诊断
ERR_CONNECTION_CLOSED

求大佬解答

代码都是书中代码

Answer 1

httpserver服务没启动吧