Java服務器HTML5 WebSocket握手失敗咋辦？

以下這段代碼是我復制Websocket4j中的一段實現webSocket服務器代碼。本來的程序是還有一個實現webSocket客戶端程序的。我執行那個客戶程序可以與此websocket服務器端通信。但我現在想把客戶端改為瀏覽器，於是我先eclipse中運行下面的程序的Java程序:

import java.io.IOException;
 
import websocket4j.server.WebServerSocket;
import websocket4j.server.WebSocket;
 
/**
 * Example presenting an echo server using WebSocket4j.
 */
public class EchoServer extends Thread {
 
    private WebSocket ws;
 
    public EchoServer(WebSocket ws) {
        this.ws = ws;
    }
 
    private void handleConnection() {
        try {
            while (true) {
                String message = ws.getMessage();
                ws.sendMessage(message);
                System.out.println("Received: " + message);
                if (message.equals("exit"))
                    break;
            }
        } catch (IOException e) {
        }finally {
            try {
            ws.close();
            } catch (IOException e) {
            }
        }
    }
 
    public void run() {
        handleConnection();
    }
 
    public static void main(String[] args) throws IOException {
        WebServerSocket socket = new WebServerSocket(5555);
        try {
            while (true) {
                WebSocket ws = socket.accept();
                System.out.println("GET " + ws.getRequestUri());
                if (ws.getRequestUri().equals("/echo"))
                    (new EchoServer(ws)).start();
                else {
                    System.out.println("Unsupported Request-URI");
                    try {
                    ws.close();
                    } catch (IOException e) {
                    }
                }
            }
 
        } finally {
            socket.close();
        }
    }
}

然後在chrome中運行HTML頁面：

 
<html> 
    <head> 
        <title>WebSoket Demo</title> 
        <script type="text/javascript"> 
            if (!window.WebSocket) { 
                alert("WebSocket not supported by this browser!"); 
            } 
              
            function display() { 
                var valueLabel = document.getElementById("valueLabel"); 
                valueLabel.innerHTML = ""; 
                var ws = new WebSocket(
                    "ws://localhost:5555"); 
                ws.onmessage = function(evt) { 
                    valueLabel.innerHTML = evt.data; 
                }; 
 
                ws.onclose = function() { 
                }; 
 
                ws.onopen = function() { 
                    ws.send("/echo"); 
                }; 
            } 
        </script> 
    </head> 
    <body onload="display();"> 
        <div id="valueLabel"></div> 
    </body> 
</html>

刷新以上頁面時會讓服務器端Javat程序拋出以下異常信息：

Exception in thread "main" java.io.IOException: Handshake failed at websocket4j.AbstractWebSocket.<init>(Unknown Source) at websocket4j.server.WebSocket.<init>(Unknown Source) at websocket4j.server.WebServerSocket.accept(Unknown Source) at org.zou.websocket.EchoServer.main(EchoServer.java:75) Caused by: java.io.IOException: Unexpected header field: Sec-WebSocket-Key: xMj+0AdIFBLJcm7QBD7QbA== at websocket4j.server.WebSocket.handshake(Unknown Source) at websocket4j.AbstractWebSocket$HandshakeRunner.run(Unknown Source) at java.util.concurrent.Executors$RunnableAdapter.call(Unknown Source) at java.util.concurrent.FutureTask$Sync.innerRun(Unknown Source) at java.util.concurrent.FutureTask.run(Unknown Source) at java.lang.Thread.run(Unknown Source)

經調試這是上面服務器程序中的WebSocket ws = socket.accept();一句引發的。現在不知怎麼削除此異常，