org.jboss.netty.handler.codec.http.websocketx.WebSocketServerHandshaker Maven / Gradle / Ivy
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The Netty project is an effort to provide an asynchronous event-driven
network application framework and tools for rapid development of
maintainable high performance and high scalability protocol servers and
clients. In other words, Netty is a NIO client server framework which
enables quick and easy development of network applications such as protocol
servers and clients. It greatly simplifies and streamlines network
programming such as TCP and UDP socket server.
/*
* 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.ChannelHandlerContext;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.handler.codec.http.HttpRequest;
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 getSubprotocols() {
Set ret = new LinkedHashSet();
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);
/**
* 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.
*
* This is only available AFTER handshake() has been called.
*
*/
public String getSelectedSubprotocol() {
return selectedSubprotocol;
}
protected void setSelectedSubprotocol(String value) {
selectedSubprotocol = value;
}
}