/*
* 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 io.netty.example.http.websocketx.server;
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.HttpHeaders;
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 static io.netty.handler.codec.http.HttpHeaders.Names.*;
import static io.netty.handler.codec.http.HttpMethod.*;
import static io.netty.handler.codec.http.HttpResponseStatus.*;
import static io.netty.handler.codec.http.HttpVersion.*;
/**
* Handles handshakes and messages
*/
public class WebSocketServerHandler extends SimpleChannelInboundHandler<Object> {
private static final String WEBSOCKET_PATH = "/websocket";
private WebSocketServerHandshaker handshaker;
@Override
public void channelRead0(ChannelHandlerContext ctx, Object msg) {
if (msg instanceof FullHttpRequest) {
handleHttpRequest(ctx, (FullHttpRequest) msg);
} else if (msg instanceof WebSocketFrame) {
handleWebSocketFrame(ctx, (WebSocketFrame) msg);
}
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.flush();
}
private void handleHttpRequest(ChannelHandlerContext ctx, FullHttpRequest req) {
// Handle a bad request.
if (!req.getDecoderResult().isSuccess()) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, BAD_REQUEST));
return;
}
// Allow only GET methods.
if (req.getMethod() != GET) {
sendHttpResponse(ctx, req, new DefaultFullHttpResponse(HTTP_1_1, FORBIDDEN));
return;
}
// Send the demo page and favicon.ico
if ("/".equals(req.getUri())) {
ByteBuf content = WebSocketServerIndexPage.getContent(getWebSocketLocation(req));
FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, OK, content);
res.headers().set(CONTENT_TYPE, "text/html; charset=UTF-8");
HttpHeaders.setContentLength(res, content.readableBytes());
sendHttpResponse(ctx, req, res);
return;
}
if ("/favicon.ico".equals(req.getUri())) {
FullHttpResponse res = new DefaultFullHttpResponse(HTTP_1_1, NOT_FOUND);
sendHttpResponse(ctx, req, res);
return;
}
// Handshake
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(ChannelHandlerContext ctx, 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 TextWebSocketFrame)) {
throw new UnsupportedOperationException(String.format("%s frame types not supported", frame.getClass()
.getName()));
}
// Send the uppercase string back.
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(
ChannelHandlerContext ctx, FullHttpRequest req, FullHttpResponse res) {
// Generate an error page if response getStatus code is not OK (200).
if (res.getStatus().code() != 200) {
ByteBuf buf = Unpooled.copiedBuffer(res.getStatus().toString(), CharsetUtil.UTF_8);
res.content().writeBytes(buf);
buf.release();
HttpHeaders.setContentLength(res, res.content().readableBytes());
}
// Send the response and close the connection if necessary.
ChannelFuture f = ctx.channel().writeAndFlush(res);
if (!HttpHeaders.isKeepAlive(req) || res.getStatus().code() != 200) {
f.addListener(ChannelFutureListener.CLOSE);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
ctx.close();
}
private static String getWebSocketLocation(FullHttpRequest req) {
String location = req.headers().get(HOST) + WEBSOCKET_PATH;
if (WebSocketServer.SSL) {
return "wss://" + location;
} else {
return "ws://" + location;
}
}
}