/*
* Copyright 2011 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 java.util.LinkedHashSet;
import java.util.Set;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelFutureListener;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.handler.codec.http.HttpRequest;
/**
* Base class for server side web socket opening and closing handshakes
*/
public abstract class WebSocketServerHandshaker {
private final String webSocketUrl;
private final String[] subprotocols;
private final WebSocketVersion version;
private final long maxFramePayloadLength;
/**
* {@link ChannelFutureListener} which will call {@link Channels#fireExceptionCaught(org.jboss.netty.channel.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 = subprotocols.split(",");
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>();
for (String p: this.subprotocols) {
ret.add(p);
}
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);
/**
* 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[] requesteSubprotocolArray = requestedSubprotocols.split(",");
for (String p: requesteSubprotocolArray) {
String requestedSubprotocol = p.trim();
for (String supportedSubprotocol: subprotocols) {
if (requestedSubprotocol.equals(supportedSubprotocol)) {
return requestedSubprotocol;
}
}
}
// No match found
return null;
}
}