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 netty; 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.FullHttpResponse; import io.netty.handler.codec.http.HttpHeaderNames; import io.netty.handler.codec.http.HttpResponseStatus; import io.netty.handler.codec.http.HttpUtil; import io.netty.handler.codec.http.websocketx.BinaryWebSocketFrame; 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; import java.nio.ByteBuffer; import static io.netty.handler.codec.http.HttpHeaderNames.CONTENT_TYPE; import static io.netty.handler.codec.http.HttpMethod.GET; import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST; import static io.netty.handler.codec.http.HttpResponseStatus.FORBIDDEN; import static io.netty.handler.codec.http.HttpResponseStatus.NOT_FOUND; import static io.netty.handler.codec.http.HttpResponseStatus.OK; import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1; /** * Handles handshakes and messages */ public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> { private static final String WEBSOCKET_PATH = "/websocket"; private WebSocketServerHandshaker handshaker; @Override public void channelRead0(final ChannelHandlerContext ctx, final Object msg) throws Exception { if (msg instanceof FullHttpRequest) { handleHttpRequest(ctx, (FullHttpRequest) msg); } else if (msg instanceof WebSocketFrame) { handleWebSocketFrame(ctx, (WebSocketFrame) msg); } } @Override public void channelReadComplete(final ChannelHandlerContext ctx) { ctx.flush(); } private void handleHttpRequest(final ChannelHandlerContext ctx, final FullHttpRequest req) { // Handle a bad request. if (!req.decoderResult().isSuccess()) { sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST)); return; } // Allow only GET methods. if (req.method() != GET) { sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN)); return; } // Send the demo page and favicon.ico if ("/".equals(req.uri())) { final ByteBuf content = WebSocketServerIndexPage.getContent(getWebSocketLocation(req)); final FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, OK, content); res.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8"); HttpUtil.setContentLength(res, content.readableBytes()); sendHttpResponse(ctx, req, res); return; } if ("/favicon.ico".equals(req.uri())) { final FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, NOT_FOUND); sendHttpResponse(ctx, req, res); return; } // Handshake final WebSocketServerHandshakerFactory wsFactory = new WebSocketServerHandshakerFactory( getWebSocketLocation(req), null, false); handshaker = wsFactory.newHandshaker(req); if (handshaker == null) { WebSocketServerHandshakerFactory.sendUnsupportedVersionResponse(ctx.channel()); } else { handshaker.handshake(ctx.channel(), req); } } private void handleWebSocketFrame(final ChannelHandlerContext ctx, final WebSocketFrame frame) { // Check for closing frame if (frame instanceof CloseWebSocketFrame) { handshaker.close(ctx.channel(), (CloseWebSocketFrame) frame.retain()); return; } if (frame instanceof PingWebSocketFrame) { ctx.channel().write(new PongWebSocketFrame(frame.content().retain())); return; } if (frame instanceof BinaryWebSocketFrame) { final BinaryWebSocketFrame bi = (BinaryWebSocketFrame) frame; final ByteBuffer bytes = bi.content().nioBuffer(); System.out.println("RECIEVING BINARY MESSAGE?!?!"); return; } if (!(frame instanceof TextWebSocketFrame)) { throw new UnsupportedOperationException( String.format("%s frame types not supported", frame.getClass().getName())); } if (frame instanceof BinaryWebSocketFrame) { System.out.println("RECIEVING BINARY MESSAGE?!?!"); } // Send the uppercase string back. final String request = ((TextWebSocketFrame) frame).text(); System.err.printf("%s received %s%n", ctx.channel(), request); ctx.channel().write(new TextWebSocketFrame(request.toUpperCase())); } private static void sendHttpResponse(final ChannelHandlerContext ctx, final FullHttpRequest req, final FullHttpResponse res) { // Generate an error page if response getStatus code is not OK (200). if (res.status() != HttpResponseStatus.OK) { final ByteBuf buf = Unpooled.copiedBuffer(res.status().toString(), CharsetUtil.UTF_8); res.content().writeBytes(buf); buf.release(); HttpUtil.setContentLength(res, res.content().readableBytes()); } // Send the response and close the connection if necessary. ChannelFuture f = ctx.channel().writeAndFlush(res); if (!HttpUtil.isKeepAlive(req) || res.status() != HttpResponseStatus.OK) { f.addListener(ChannelFutureListener.CLOSE); } } @Override public final void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) { cause.printStackTrace(); ctx.close(); } private static String getWebSocketLocation(final FullHttpRequest req) { final String location = req.headers().get(HttpHeaderNames.HOST) + WEBSOCKET_PATH; if (WebSocketRunner.SSL) { return "wss://" + location; } else { return "ws://" + location; } } }