Embedded Jetty 9一次处理一个请求

我在嵌入模式下使用jetty 9，即使我给了一个500的threadpool ，服务器仍然只是一次处理一个请求。

我错过了什么？

JAVA代码：
//这里我希望所有线程名称日志能够即时打印，但它们会逐个打印

 public class Main { public static void main(String[] arg) throws Exception { ExecutorThreadPool executorThreadPool = new ExecutorThreadPool(Executors.newFixedThreadPool(500)); final Server server = new Server(executorThreadPool); final ServerConnector connector0 = new ServerConnector(server); connector0.addBean(executorThreadPool); connector0.setPort(8080); server.setHandler(new HelloHandler()); server.setConnectors(new Connector[] {connector0}); server.setDumpAfterStart(true); server.start(); server.join(); } } class HelloHandler extends AbstractHandler { public void handle(String target,Request baseRequest,HttpServletRequest request,HttpServletResponse response) throws IOException, ServletException { try { System.out.println("Thread Name+" + Thread.currentThread().getName()); Thread.sleep(3000l); } catch (InterruptedException e) { // TODO Auto-generated catch block e.printStackTrace(); } response.setContentType("text/html;charset=utf-8"); response.setStatus(HttpServletResponse.SC_OK); baseRequest.setHandled(true); response.getWriter().println("
Hello World
"); } } 

的pom.xml

  4.0.0 Test test 0.0.1-SNAPSHOT   org.eclipse.jetty jetty-server 9.2.6.v20141205    

我从浏览器中解雇JAVASCRIPT脚本来测试“

 function httpGet(theUrl) { var xmlHttp = null; xmlHttp = new XMLHttpRequest(); xmlHttp.open( "GET", theUrl, true ); xmlHttp.send( null ); return xmlHttp.responseText; } for(i=0;i<20;i++) {console.log(i);httpGet("http://localhost:8080");}