Java tutorial
/* * Copyright 2019 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.handler.codec.http.websocketx; import io.netty.channel.Channel; import io.netty.channel.ChannelFuture; import io.netty.channel.ChannelPromise; import io.netty.handler.codec.http.DefaultFullHttpResponse; import io.netty.handler.codec.http.HttpHeaderNames; import io.netty.handler.codec.http.HttpUtil; import io.netty.handler.codec.http.HttpRequest; import io.netty.handler.codec.http.HttpResponse; import io.netty.handler.codec.http.HttpResponseStatus; import io.netty.handler.codec.http.HttpVersion; import io.netty.util.internal.ObjectUtil; /** * Auto-detects the version of the Web Socket protocol in use and creates a new proper * {@link WebSocketServerHandshaker}. */ public class WebSocketServerHandshakerFactory { private final String webSocketURL; private final String subprotocols; private final WebSocketDecoderConfig decoderConfig; /** * Constructor specifying the destination web socket location * * @param webSocketURL * URL for web socket communications. e.g "ws://myhost.com/mypath". * Subsequent web socket frames will be sent to this URL. * @param subprotocols * CSV of supported protocols. Null if sub protocols not supported. * @param allowExtensions * Allow extensions to be used in the reserved bits of the web socket frame */ public WebSocketServerHandshakerFactory(String webSocketURL, String subprotocols, boolean allowExtensions) { this(webSocketURL, subprotocols, allowExtensions, 65536); } /** * Constructor specifying the destination web socket location * * @param webSocketURL * URL for web socket communications. e.g "ws://myhost.com/mypath". * Subsequent web socket frames will be sent to this URL. * @param subprotocols * CSV of supported protocols. Null if sub protocols not supported. * @param allowExtensions * Allow extensions to be used in the reserved bits of the web socket frame * @param maxFramePayloadLength * Maximum allowable frame payload length. Setting this value to your application's * requirement may reduce denial of service attacks using long data frames. */ public WebSocketServerHandshakerFactory(String webSocketURL, String subprotocols, boolean allowExtensions, int maxFramePayloadLength) { this(webSocketURL, subprotocols, allowExtensions, maxFramePayloadLength, false); } /** * Constructor specifying the destination web socket location * * @param webSocketURL * URL for web socket communications. e.g "ws://myhost.com/mypath". * Subsequent web socket frames will be sent to this URL. * @param subprotocols * CSV of supported protocols. Null if sub protocols not supported. * @param allowExtensions * Allow extensions to be used in the reserved bits of the web socket frame * @param maxFramePayloadLength * Maximum allowable frame payload length. Setting this value to your application's * requirement may reduce denial of service attacks using long data frames. * @param allowMaskMismatch * When set to true, frames which are not masked properly according to the standard will still be * accepted. */ public WebSocketServerHandshakerFactory(String webSocketURL, String subprotocols, boolean allowExtensions, int maxFramePayloadLength, boolean allowMaskMismatch) { this(webSocketURL, subprotocols, WebSocketDecoderConfig.newBuilder().allowExtensions(allowExtensions) .maxFramePayloadLength(maxFramePayloadLength).allowMaskMismatch(allowMaskMismatch).build()); } /** * Constructor specifying the destination web socket location * * @param webSocketURL * URL for web socket communications. e.g "ws://myhost.com/mypath". * Subsequent web socket frames will be sent to this URL. * @param subprotocols * CSV of supported protocols. Null if sub protocols not supported. * @param decoderConfig * Frames decoder options. */ public WebSocketServerHandshakerFactory(String webSocketURL, String subprotocols, WebSocketDecoderConfig decoderConfig) { this.webSocketURL = webSocketURL; this.subprotocols = subprotocols; this.decoderConfig = ObjectUtil.checkNotNull(decoderConfig, "decoderConfig"); } /** * Instances a new handshaker * * @return A new WebSocketServerHandshaker for the requested web socket version. Null if web * socket version is not supported. */ public WebSocketServerHandshaker newHandshaker(HttpRequest req) { CharSequence version = req.headers().get(HttpHeaderNames.SEC_WEBSOCKET_VERSION); if (version != null) { if (version.equals(WebSocketVersion.V13.toHttpHeaderValue())) { // Version 13 of the wire protocol - RFC 6455 (version 17 of the draft hybi specification). return new WebSocketServerHandshaker13(webSocketURL, subprotocols, decoderConfig); } else if (version.equals(WebSocketVersion.V08.toHttpHeaderValue())) { // Version 8 of the wire protocol - version 10 of the draft hybi specification. return new WebSocketServerHandshaker08(webSocketURL, subprotocols, decoderConfig); } else if (version.equals(WebSocketVersion.V07.toHttpHeaderValue())) { // Version 8 of the wire protocol - version 07 of the draft hybi specification. return new WebSocketServerHandshaker07(webSocketURL, subprotocols, decoderConfig); } else { return null; } } else { // Assume version 00 where version header was not specified return new WebSocketServerHandshaker00(webSocketURL, subprotocols, decoderConfig); } } /** * @deprecated use {@link #sendUnsupportedVersionResponse(Channel)} */ @Deprecated public static void sendUnsupportedWebSocketVersionResponse(Channel channel) { sendUnsupportedVersionResponse(channel); } /** * Return that we need cannot not support the web socket version */ public static ChannelFuture sendUnsupportedVersionResponse(Channel channel) { return sendUnsupportedVersionResponse(channel, channel.newPromise()); } /** * Return that we need cannot not support the web socket version */ public static ChannelFuture sendUnsupportedVersionResponse(Channel channel, ChannelPromise promise) { HttpResponse res = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.UPGRADE_REQUIRED, channel.alloc().buffer(0)); res.headers().set(HttpHeaderNames.SEC_WEBSOCKET_VERSION, WebSocketVersion.V13.toHttpHeaderValue()); HttpUtil.setContentLength(res, 0); return channel.writeAndFlush(res, promise); } }