【websocket】为啥就是握手不成功呢？没看出有关问题来

【websocket】为啥就是握手不成功呢？没看出问题来啊
tomcat服务器端：
处理websocket连接

package websocket;

import javax.servlet.http.HttpServletRequest;
import org.apache.catalina.websocket.StreamInbound;
import org.apache.catalina.websocket.WebSocketServlet;

public class WebSocketMessageServlet extends WebSocketServlet{

	@Override
	protected StreamInbound createWebSocketInbound(String arg0,
			HttpServletRequest request) {
		// TODO Auto-generated method stub
		String username= (String)request.getSession().getAttribute("user_nickname"); 
		System.out.println(username);
		return new WebSocketMessageInboundPool(username); 
	}  
}  

处理websocket请求

package websocket;

import java.io.IOException;
import java.nio.CharBuffer;
import java.nio.ByteBuffer;
import java.util.HashMap;
import java.util.Map;
import org.apache.catalina.websocket.MessageInbound;
import org.apache.catalina.websocket.WsOutbound;

public class WebSocketMessageInboundPool extends MessageInbound{
	
	private final  String user_nickname;
	private static final Map<String,WebSocketMessageInboundPool > Connections = new HashMap<String,WebSocketMessageInboundPool>();
	
	public  WebSocketMessageInboundPool(String username){
		this.user_nickname=username;
	}
	
	protected void onOpen(WsOutbound outbound) {
		// TODO Auto-generated method stub
		addMessageInbound(this);
		super.onOpen(outbound);
	}
	
	protected void onBinaryMessage(ByteBuffer arg0) throws IOException {
		// TODO Auto-generated method stub
		// 向所有已连接的客户端发送文本消息
		try {
			//向特定的用户发送数据
			WebSocketMessageInboundPool  inbound = Connections.get(user_nickname);
			if(inbound != null){
				ByteBuffer bb = ByteBuffer.wrap(arg0.array());
				WsOutbound wb = inbound.getWsOutbound();
				wb.writeBinaryMessage(bb);
				wb.flush();
			}
		}
		catch (IOException e) {
			e.printStackTrace();
		}
	}
	
	protected void onTextMessage(CharBuffer arg0) throws IOException {
		// TODO Auto-generated method stub	
		try {
			//向特定的用户发送数据
			WebSocketMessageInboundPool  inbound = Connections.get(user_nickname);
			if(inbound != null){
			CharBuffer cb = CharBuffer.wrap(arg0);
			WsOutbound wb = inbound.getWsOutbound();
			wb.writeTextMessage(cb);
			wb.flush();
			}
		}
		catch (IOException e) {
				e.printStackTrace();
			}
		}
	
	protected void onClose(int status) {
		// TODO Auto-generated method stub
		removeMessageInbound(this);
		super.onClose(status);
	}
	
	//向连接池中添加连接
	public static void addMessageInbound(WebSocketMessageInboundPool  inbound){
		//添加连接
		Connections.put(inbound.user_nickname, inbound);
	}
	public static void removeMessageInbound(WebSocketMessageInboundPool  inbound){
		//移除连接
		Connections.remove(inbound.user_nickname);
	}
}

xml配置

<?xml version="1.0" encoding="UTF-8"?>
<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></display-name>	
  
  <servlet>
  	<servlet-name>WebSocketMessageServlet</servlet-name>
  	<servlet-class>websocket.WebSocketMessageServlet</servlet-class>
  </servlet>
  <servlet-mapping>
  	<servlet-name>WebSocketMessageServlet</servlet-name>
  	<url-pattern>/web</url-pattern>
  </servlet-mapping>
  
  <welcome-file-list>
    <welcome-file>index.jsp</welcome-file>
  </welcome-file-list>
</web-app>

ws：ws = new WebSocket("ws://192.168.3.51/S2012150143/web");   

tomcat中WEB-INF下lib中的jar包都删了

死活握手不成功！！！！！！

------解决方案--------------------
和服务器版本有关系，这个tomcat服务器可能版本太低。