Java tutorial
/* * Copyright 2012 The Netty Project * * The Netty Project licenses this file to you under the Apache License, * version 2.0 (the "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at: * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the * License for the specific language governing permissions and limitations * under the License. */ package com.igeeksky.xcafe.core.handler; import java.util.Locale; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.SimpleChannelInboundHandler; import io.netty.handler.codec.http.websocketx.TextWebSocketFrame; import io.netty.handler.codec.http.websocketx.WebSocketFrame; import org.slf4j.Logger; import org.slf4j.LoggerFactory; /** * Echoes uppercase content of text frames. */ public class WebSocketFrameHandler extends SimpleChannelInboundHandler<WebSocketFrame> { private static final Logger logger = LoggerFactory.getLogger(WebSocketFrameHandler.class); @Override protected void channelRead0(ChannelHandlerContext ctx, WebSocketFrame frame) throws Exception { // ping and pong frames already handled if (frame instanceof TextWebSocketFrame) { // Send the uppercase string back. String request = ((TextWebSocketFrame) frame).text(); logger.info("{} received {}", ctx.channel(), request); ctx.channel().writeAndFlush(new TextWebSocketFrame(request.toUpperCase(Locale.US))); } else { String message = "unsupported frame type: " + frame.getClass().getName(); throw new UnsupportedOperationException(message); } } }