NettyHttpTransportSourceHandler.java Source code

Introduction

Here is the source code for NettyHttpTransportSourceHandler.java

Source

/*
 *  Licensed to the Apache Software Foundation (ASF) under one
 *  or more contributor license agreements.  See the NOTICE file
 *  distributed with this work for additional information
 *  regarding copyright ownership.  The ASF 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.
 */
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.PooledByteBufAllocator;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;

/**
 * actual event handling class for netty
 */
public class NettyHttpTransportSourceHandler extends ChannelInboundHandlerAdapter {

    private volatile Channel outboundChannel;
    private final int maxConnectionsQueued;

    public NettyHttpTransportSourceHandler(int maxConnectionsQueued) {
        this.maxConnectionsQueued = maxConnectionsQueued;
    }

    /**
     * activating registered handler to accept events.
     *
     * @param ctx
     * @throws Exception
     */
    @Override
    public void channelActive(ChannelHandlerContext ctx) throws Exception {

        final Channel inboundChannel = ctx.channel();

        Bootstrap b = new Bootstrap();
        b.group(inboundChannel.eventLoop()).channel(ctx.channel().getClass());
        b.handler(new NettyTargetHandlerInitilizer(inboundChannel)).option(ChannelOption.AUTO_READ, false);

        b.option(ChannelOption.ALLOCATOR, PooledByteBufAllocator.DEFAULT);
        b.option(ChannelOption.TCP_NODELAY, true);
        b.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 15000);

        b.option(ChannelOption.SO_SNDBUF, 1048576);
        b.option(ChannelOption.SO_RCVBUF, 1048576);

        ChannelFuture f = b.connect(NettyHttpListner.HOST, NettyHttpListner.HOST_PORT);

        outboundChannel = f.channel();
        f.addListener(new ChannelFutureListener() {
            @Override
            public void operationComplete(ChannelFuture future) throws Exception {
                if (future.isSuccess()) {
                    // connection complete start to read first data
                    inboundChannel.read();
                } else {
                    // Close the connection if the connection attempt has failed.
                    inboundChannel.close();
                }
            }
        });

    }

    /**
     * receiving events through netty.
     *
     * @param ctx
     * @param msg
     * @throws Exception
     */
    @Override
    public void channelRead(final ChannelHandlerContext ctx, Object msg) throws Exception {

        if (outboundChannel.isActive()) {
            outboundChannel.writeAndFlush(msg).addListener(new ChannelFutureListener() {
                @Override
                public void operationComplete(ChannelFuture future) throws Exception {
                    if (future.isSuccess()) {
                        // was able to flush out data, start to read the next chunk
                        ctx.channel().read();
                    } else {
                        future.channel().close();
                    }
                }
            });
        } else {
            // System.out.println("Outbound Channel Not Active");
        }
    }

    @Override
    public void channelInactive(ChannelHandlerContext ctx) throws Exception {
        //  System.out.println("Channel Inactive");
        if (outboundChannel != null) {
            closeOnFlush(outboundChannel);
        }
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
        //  System.out.println("Exception caught");
        cause.printStackTrace();
        closeOnFlush(ctx.channel());
    }

    /**
     * Closes the specified channel after all queued write requests are flushed.
     */
    static void closeOnFlush(Channel ch) {
        if (ch.isActive()) {
            ch.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);
        }
    }
}