CorsOutboundHandler.java

/*
 * 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.handler;

import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelPromise;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpResponse;
import io.netty.util.internal.logging.InternalLogger;
import io.netty.util.internal.logging.InternalLoggerFactory;

public class CorsOutboundHandler extends ChannelHandlerAdapter {
    private static final InternalLogger logger = InternalLoggerFactory.getInstance(CorsOutboundHandler.class);

    @Override
    public void write(final ChannelHandlerContext ctx, final Object msg, final ChannelPromise promise)
            throws Exception {
        if (msg instanceof HttpResponse) {
            final HttpResponse response = (HttpResponse) msg;
            final CorsMetadata cmd = ctx.channel().attr(CorsInboundHandler.CORS).get();
            if (cmd != null) {
                response.headers().set(HttpHeaders.Names.ACCESS_CONTROL_ALLOW_ORIGIN, cmd.origin());
                if (cmd.hasHeaders()) {
                    response.headers().set(HttpHeaders.Names.ACCESS_CONTROL_ALLOW_HEADERS, cmd.headers());
                }
                response.headers().set(HttpHeaders.Names.ACCESS_CONTROL_ALLOW_CREDENTIALS, "true");
            }
        }
        ctx.writeAndFlush(msg, promise);
    }

    @Override
    public void exceptionCaught(final ChannelHandlerContext ctx, final Throwable cause) throws Exception {
        logger.error("caught error in CorsOutboundHandler", cause);
        ctx.fireExceptionCaught(cause);
    }

}