WebSocket connection to 'ws://127.0.0.1:?报错

java代码如下

import java.util.concurrent.TimeUnit;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
import javax.websocket.server.ServerEndpoint;

@ServerEndpoint("/cmd/prog")
public class Progress
{
	@OnMessage
	public void onMessage(String msg, Session session) throws Exception
	{
		System.out.println("-------onMessage-------");
		System.out.println("msg : " + msg);
		System.out.println(session.getQueryString());
		
		for(int i=0;i<=100;i++)
		{
			String tmp = "让我们定义一个 Java EE websocket服务器端" + i;
			System.out.println("send msg : " + tmp);
			session.getBasicRemote().sendText(tmp);
			TimeUnit.SECONDS.sleep(1l);
		}
	}
	
	@OnOpen
	public void onOpen()
	{
		System.out.println("------------onOpen------------");
	}
	
	@OnClose
	public void onClose()
	{
		System.out.println("------------onClose------------");
	}
}

maven配置的依赖是：

<dependency>
			<groupId>javax.websocket</groupId>
			<artifactId>javax.websocket-api</artifactId>
			<version>1.1</version>
		</dependency>

<button onclick="start()">测试</button>
<div id="messages"></div>
<script type="text/javascript">

	var webSocket = null;
	
	function init()
	{
		webSocket = new WebSocket('ws://127.0.0.1:8080/cmd/prog');
		
		webSocket.onerror = function(event) 
		{
		  onError(event)
		};
		
		webSocket.onopen = function(event) 
		{
		  onOpen(event)
		};
		
		webSocket.onmessage = function(event)
		{
		  onMessage(event)
		};
	}
	
	function onMessage(event)
	{
	  	document.getElementById('messages').innerHTML += '<br />' + event.data;
	}
	
	function onOpen(event) 
	{
	  	document.getElementById('messages').innerHTML  = 'Connection established';
	}
	
	function onError(event) 
	{
	  	alert(event.data);
	}
	
	function start() 
	{
		init();
	}
</script>

http://127.0.0.1:8080/index.jsp

点击按钮，报错：

WebSocket connection to 'ws://127.0.0.1:8080/cmd/prog' failed: Error during WebSocket handshake: Unexpected response code: 404

系统运行环境为：

jdk1.8 x64, tomcat7.0.57

网上貌似是说，要引入tomcat-socket的jar，但是这样做，肯定只能在tomcat下运行，不能在其他web server下运行

请问，怎么解决。