/*
* 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 org.jboss.netty.handler.codec.http.websocketx;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.ChannelHandler;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.handler.codec.http.HttpChunkAggregator;
import org.jboss.netty.handler.codec.http.HttpRequest;
import org.jboss.netty.handler.codec.http.HttpRequestDecoder;
import org.jboss.netty.handler.codec.http.HttpResponse;
import org.jboss.netty.handler.codec.http.HttpResponseEncoder;
import org.jboss.netty.util.internal.StringUtil;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;
/**
* Base class for server side web socket opening and closing handshakes
*/
public abstract class WebSocketServerHandshaker {
/**
* Use this as wildcard to support all requested sub-protocols
*/
public static final String SUB_PROTOCOL_WILDCARD = "*";
private final String webSocketUrl;
private final String[] subprotocols;
private final WebSocketVersion version;
private final long maxFramePayloadLength;
private String selectedSubprotocol;
/**
* {@link ChannelFutureListener} which will call
* {@link Channels#fireExceptionCaught(ChannelHandlerContext, Throwable)}
* if the {@link ChannelFuture} was not successful.
*/
public static final ChannelFutureListener HANDSHAKE_LISTENER = new ChannelFutureListener() {
public void operationComplete(ChannelFuture future) throws Exception {
if (!future.isSuccess()) {
Channels.fireExceptionCaught(future.getChannel(), future.getCause());
}
}
};
/**
* Constructor using default values
*
* @param version
* the protocol version
* @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.
*/
protected WebSocketServerHandshaker(WebSocketVersion version, String webSocketUrl, String subprotocols) {
this(version, webSocketUrl, subprotocols, Long.MAX_VALUE);
}
/**
* Constructor specifying the destination web socket location
*
* @param version
* the protocol version
* @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 maxFramePayloadLength
* Maximum length of a frame's payload
*/
protected WebSocketServerHandshaker(WebSocketVersion version, String webSocketUrl, String subprotocols,
long maxFramePayloadLength) {
this.version = version;
this.webSocketUrl = webSocketUrl;
if (subprotocols != null) {
String[] subprotocolArray = StringUtil.split(subprotocols, ',');
for (int i = 0; i < subprotocolArray.length; i++) {
subprotocolArray[i] = subprotocolArray[i].trim();
}
this.subprotocols = subprotocolArray;
} else {
this.subprotocols = new String[0];
}
this.maxFramePayloadLength = maxFramePayloadLength;
}
/**
* Returns the URL of the web socket
*/
public String getWebSocketUrl() {
return webSocketUrl;
}
/**
* Returns the CSV of supported sub protocols
*/
public Set<String> getSubprotocols() {
Set<String> ret = new LinkedHashSet<String>();
Collections.addAll(ret, subprotocols);
return ret;
}
/**
* Returns the version of the specification being supported
*/
public WebSocketVersion getVersion() {
return version;
}
/**
* Returns the max length for any frame's payload
*/
public long getMaxFramePayloadLength() {
return maxFramePayloadLength;
}
/**
* Performs the opening handshake
*
* @param channel
* Channel
* @param req
* HTTP Request
*/
public abstract ChannelFuture handshake(Channel channel, HttpRequest req);
/**
* Upgrades the connection and send the handshake response.
*/
protected ChannelFuture writeHandshakeResponse(
Channel channel, HttpResponse res, ChannelHandler encoder, ChannelHandler decoder) {
final ChannelPipeline p = channel.getPipeline();
if (p.get(HttpChunkAggregator.class) != null) {
p.remove(HttpChunkAggregator.class);
}
final String httpEncoderName = p.getContext(HttpResponseEncoder.class).getName();
p.addAfter(httpEncoderName, "wsencoder", encoder);
p.get(HttpRequestDecoder.class).replace("wsdecoder", decoder);
final ChannelFuture future = channel.write(res);
future.addListener(new ChannelFutureListener() {
public void operationComplete(ChannelFuture future) {
p.remove(httpEncoderName);
}
});
return future;
}
/**
* Performs the closing handshake
*
* @param channel
* Channel
* @param frame
* Closing Frame that was received
*/
public abstract ChannelFuture close(Channel channel, CloseWebSocketFrame frame);
/**
* Selects the first matching supported sub protocol
*
* @param requestedSubprotocols
* CSV of protocols to be supported. e.g. "chat, superchat"
* @return First matching supported sub protocol. Null if not found.
*/
protected String selectSubprotocol(String requestedSubprotocols) {
if (requestedSubprotocols == null || subprotocols.length == 0) {
return null;
}
String[] requestedSubprotocolArray = StringUtil.split(requestedSubprotocols, ',');
for (String p : requestedSubprotocolArray) {
String requestedSubprotocol = p.trim();
for (String supportedSubprotocol : subprotocols) {
if (SUB_PROTOCOL_WILDCARD.equals(supportedSubprotocol) ||
requestedSubprotocol.equals(supportedSubprotocol)) {
return requestedSubprotocol;
}
}
}
// No match found
return null;
}
/**
* Returns the selected subprotocol. Null if no subprotocol has been selected.
* <p>
* This is only available AFTER <tt>handshake()</tt> has been called.
* </p>
*/
public String getSelectedSubprotocol() {
return selectedSubprotocol;
}
protected void setSelectedSubprotocol(String value) {
selectedSubprotocol = value;
}
}