Java tutorial
/* * Copyright (c) 2012-2015 The original author or authors * ------------------------------------------------------ * All rights reserved. This program and the accompanying materials * are made available under the terms of the Eclipse Public License v1.0 * and Apache License v2.0 which accompanies this distribution. * * The Eclipse Public License is available at * http://www.eclipse.org/legal/epl-v10.html * * The Apache License v2.0 is available at * http://www.opensource.org/licenses/apache2.0.php * * You may elect to redistribute this code under either of these licenses. */ package io.moquette.server.netty.metrics; import io.netty.channel.ChannelDuplexHandler; import io.netty.channel.ChannelHandlerContext; import io.netty.channel.ChannelPromise; import io.netty.util.Attribute; import io.netty.util.AttributeKey; public class MessageMetricsHandler extends ChannelDuplexHandler { private static final AttributeKey<MessageMetrics> ATTR_KEY_METRICS = AttributeKey.valueOf("MessageMetrics"); private MessageMetricsCollector m_collector; public MessageMetricsHandler(MessageMetricsCollector collector) { m_collector = collector; } @Override public void channelActive(ChannelHandlerContext ctx) throws Exception { Attribute<MessageMetrics> attr = ctx.attr(ATTR_KEY_METRICS); attr.set(new MessageMetrics()); super.channelActive(ctx); } @Override public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { MessageMetrics metrics = ctx.attr(ATTR_KEY_METRICS).get(); metrics.incrementRead(1); ctx.fireChannelRead(msg); } @Override public void write(ChannelHandlerContext ctx, Object msg, ChannelPromise promise) throws Exception { MessageMetrics metrics = ctx.attr(ATTR_KEY_METRICS).get(); metrics.incrementWrote(1); ctx.write(msg, promise); } @Override public void close(ChannelHandlerContext ctx, ChannelPromise promise) throws Exception { MessageMetrics metrics = ctx.attr(ATTR_KEY_METRICS).get(); m_collector.sumReadMessages(metrics.messagesRead()); m_collector.sumWroteMessages(metrics.messagesWrote()); super.close(ctx, promise); } }