netty5写回websocket的数据，websocket接收不到

Question

handler处理如下

package com.amarky.websocket;

import org.apache.log4j.Logger;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.SimpleChannelInboundHandler;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpVersion;
import io.netty.handler.codec.http.websocketx.CloseWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PingWebSocketFrame;
import io.netty.handler.codec.http.websocketx.PongWebSocketFrame;
import io.netty.handler.codec.http.websocketx.TextWebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketFrame;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshaker;
import io.netty.handler.codec.http.websocketx.WebSocketServerHandshakerFactory;
import io.netty.util.CharsetUtil;


/**
 * 
 * @author AMARKY
 * @date 2016年9月8日
 * @Desc 处理WEBSOCKET的请求
 */
public class WebsocketServerHandler extends SimpleChannelInboundHandler<Object> {


    private static final Logger logger = Logger.getLogger(WebsocketServerHandler.class.getName());
    private WebSocketServerHandshaker handsharker;


    /**
     * 接受数据
     */
    @Override
    protected void messageReceived(ChannelHandlerContext ctx, Object msg) throws Exception {
        // 如果是HTTP请求
        if (msg instanceof FullHttpRequest) {
            handleHttpRequest(ctx, (FullHttpRequest) msg);
        }
        // WEBSOCKET接入
        else if (msg instanceof WebSocketFrame) {
            handleWebSocketFrame(ctx, (WebSocketFrame) msg);
        }
    }


    /**
     * 数据处理完成后,刷新出去
     */
    @Override
    public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
        ctx.flush();
    }


    /**
     * 处理HTTP请求
     * 
     * @param ctx
     * @param msg
     */
    private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) {
        // 如果解码失败,返回异常
        if (!req.getDecoderResult().isSuccess() || (!"websocket".equals(req.headers().get("Upgrade")))) {
            sendHttpResponse(ctx, new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.BAD_REQUEST));
            return;
        }
        // 构造握手相应
        WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory(
                "ws://localhost:8080/websocket", null, Boolean.FALSE);
        handsharker = wsFactory.newHandshaker(req);
        if (handsharker == null) {
            WebSocketServerHandshakerFactory.sendUnsupportedWebSocketVersionResponse(ctx.channel());
        } else {
            handsharker.handshake(ctx.channel(), req);
        }
    }


    /**
     * 处理WEBSOCKET请求
     * 
     * @param ctx
     * @param frame
     */
    private void handleWebSocketFrame(ChannelHandlerContext ctx, WebSocketFrame frame) {
        // 判断链路是否关闭
        if (frame instanceof CloseWebSocketFrame) {
            handsharker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain());
            return;
        }
        if (frame instanceof PingWebSocketFrame) {
            new PongWebSocketFrame(frame.content().retain());
            return;
        }
        // 只支持文本消息,不支持二进制消息
        if (!(frame instanceof TextWebSocketFrame)) {
            throw new UnsupportedOperationException(
                    String.format("%s frame type not supported", frame.getClass().getName()));
        }


        String request = ((TextWebSocketFrame) frame).text();


        logger.info(String.format("%s received %s", ctx.channel(), request));
        System.out.println(String.format("%s received %s", ctx.channel(), request));


        // ctx.channel().write(new TextWebSocketFrame(request + " , 欢迎使用netty
        // websocket 服务,现在时刻是: ")
        // + new java.util.Date().toString());
        ctx.channel().writeAndFlush("欢迎使用netty websocket 服务,现在时刻是: " + new java.util.Date().toString());


    }


    /**
     * 返回请求
     * 
     * @param ctx
     * @param req
     * @param defaultFullHttpResponse
     */
    private void sendHttpResponse(ChannelHandlerContext ctx, DefaultFullHttpResponse res) {
        // 返回应答的消息
        if (res.getStatus().code() != 200) {
            ByteBuf byteBuf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8);
            res.content().writeBytes(byteBuf);
            byteBuf.release();
            HttpHeaders.setContentLength(res, res.content().readableBytes());
        }
        ChannelFuture f = ctx.channel().writeAndFlush(res);
        if (!HttpHeaders.isKeepAlive(res) || res.getStatus().code() != 200) {
            f.addListener(ChannelFutureListener.CLOSE);
        }
    }


    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        ctx.close();
    }


}







websocket如下：

<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>netty 测试</title>
</head>
<body>
<script type="text/javascript">
var socket;
alert(window.WebSocket);
if(!window.WebSocket){
window.WebSocket = window.MozWebSocket;
}
if(window.WebSocket){
socket = new WebSocket("ws://localhost:8080/websocket");
socket.onopen = function(event){
var ta = document.getElementById('responseText');
ta.value = "打开websocket服务正常,支持websocket服务";
};
socket.onmessage  = function(event){
var ta = document.getElementById('responseText');
ta.value = "";
ta.value = event.data;
};
socket.onclose = function(event){
var ta = document.getElementById('responseText');
ta.value = "";
ta.value = "websocket关闭";
};
}
else{
alert("不支持websocket");
}
function send(message){
if(!window.WebSocket){return;}
if(socket.readyState == WebSocket.OPEN){
socket.send(message);
}else{
alert("链接没成功");
}
}



</script>
<form onsubmit="return false;">
<input type = "text" name = "message" value = "netty实践" />
<br><br>
<input type = "button" value = "发送" onclick="send(this.form.message.value)" />
<hr color="bule" />
<h3>服务端应答消息</h3>
<textarea id = "responseText" style = "width: 500px;height: 300px"></textarea>
</form>
</body>
</html>


socket.onmessage方法接受不到writeAndFlush写回的数据，不知道是什么原因​