/*
* Copyright 2013 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.aerogear.io.netty.handler.codec.sockjs.transport;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONNECTION;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_LENGTH;
import static io.netty.handler.codec.http.HttpHeaders.Names.CONTENT_TYPE;
import static io.netty.handler.codec.http.HttpHeaders.Values.CLOSE;
import static io.netty.handler.codec.http.HttpResponseStatus.OK;
import static org.jboss.aerogear.io.netty.handler.codec.sockjs.transport.Transports.CONTENT_TYPE_JAVASCRIPT;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpRequest;
import io.netty.handler.codec.http.FullHttpResponse;
import org.jboss.aerogear.io.netty.handler.codec.sockjs.SockJsConfig;
import org.jboss.aerogear.io.netty.handler.codec.sockjs.protocol.Frame;
import org.jboss.aerogear.io.netty.handler.codec.sockjs.util.ArgumentUtil;
import io.netty.util.ReferenceCountUtil;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;
/**
* XMLHttpRequest (XHR) Polling is a transport where there is no open connection between
* the client and the server. Instead the client will issue a new request for polling from
* and sending data to the SockJS service.
*
* This handler is responsible for handling {@link Frame}s and sending the
* content back to the client. These frames are generated by the SockJS session handling.
*
* @see XhrSendTransport
*/
public class XhrPollingTransport extends ChannelHandlerAdapter {
private static final InternalLogger logger = InternalLoggerFactory.getInstance(XhrPollingTransport.class);
private final SockJsConfig config;
private final FullHttpRequest request;
/**
* Sole constructor.
*
* @param config the SockJS {@link SockJsConfig} instance.
* @param request the {@link FullHttpRequest} which can be used get information like the HTTP version.
*/
public XhrPollingTransport(final SockJsConfig config, final FullHttpRequest request) {
ArgumentUtil.checkNotNull(config, "config");
ArgumentUtil.checkNotNull(request, "request");
this.config = config;
this.request = request;
this.request.retain();
}
@Override
public void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise)
throws Exception {
if (msg instanceof Frame) {
final Frame frame = (Frame) msg;
final ByteBuf content = Transports.wrapWithLN(frame.content());
frame.release();
final FullHttpResponse response = new DefaultFullHttpResponse(request.getProtocolVersion(), OK, content);
response.headers().set(CONTENT_TYPE, CONTENT_TYPE_JAVASCRIPT);
response.headers().set(CONTENT_LENGTH, content.readableBytes());
response.headers().set(CONNECTION, CLOSE);
Transports.setDefaultHeaders(response, config, request);
Transports.writeResponse(ctx, promise, response);
} else {
ctx.writeAndFlush(ReferenceCountUtil.retain(msg), promise);
}
}
@Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
logger.error("caught exception : ", cause);
ctx.fireExceptionCaught(cause);
}
}