CloseConnectionChannelHandler.java

package com.tacitknowledge.slowlight.proxyserver.handler;

import com.tacitknowledge.slowlight.proxyserver.config.HandlerConfig;
import io.netty.channel.ChannelHandlerContext;

import java.util.concurrent.TimeUnit;

/**
 * CloseConnectionChannelHandler class allows to control when the channel connection should be dropped (closed).<br />
 * <br />
 * Handler parameters:<br />
 * 1. <b>closeConnectionAfter</b> - defines the time in milliseconds after which the connection will be closed.
 * Setting this parameter to 0 will cause the connection to be closed immediately<br />
 *
 * @author Alexandr Donciu (adonciu@tacitknowledge.com)
 */
public class CloseConnectionChannelHandler extends AbstractChannelHandler
{
    private static final String PARAM_CLOSE_CONNECTION_AFTER = "closeConnectionAfter";

    public CloseConnectionChannelHandler(final HandlerConfig handlerConfig)
    {
        super(handlerConfig);
    }

    @Override
    public void channelActive(final ChannelHandlerContext ctx) throws Exception
    {
        final long closeConnectionAfter = handlerParams.getLong(PARAM_CLOSE_CONNECTION_AFTER);

        if (closeConnectionAfter == 0)
        {
            closeConnection(ctx);
        }
        else
        {
            scheduleCloseConnection(ctx, closeConnectionAfter);
        }

        ctx.fireChannelActive();
    }

    @Override
    public void channelRead(final ChannelHandlerContext ctx, final Object msg) throws Exception
    {
        ctx.fireChannelRead(msg);
    }

    @Override
    protected void populateHandlerParams()
    {
        handlerParams.setProperty(PARAM_CLOSE_CONNECTION_AFTER, handlerConfig.getParam(PARAM_CLOSE_CONNECTION_AFTER));
    }

    private void scheduleCloseConnection(final ChannelHandlerContext ctx, final long closeConnectionAfter)
    {
        ctx.executor().schedule(new CloseConnectionRunnable(ctx), closeConnectionAfter, TimeUnit.MILLISECONDS);
    }

    private void closeConnection(final ChannelHandlerContext ctx)
    {
        ctx.channel().close();
    }

    /**
     * Runnable to close channel connection.
     */
    protected class CloseConnectionRunnable implements Runnable
    {
        private final ChannelHandlerContext ctx;

        protected CloseConnectionRunnable(final ChannelHandlerContext ctx)
        {
            this.ctx = ctx;
        }

        @Override
        public void run()
        {
            closeConnection(ctx);
        }
    }
}