/*
 * Copyright 2012 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 io.netty.example.uptime;

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelFutureListener;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.timeout.IdleStateHandler;


Connects to a server periodically to measure and print the uptime of the server. This example demonstrates how to implement reliable reconnection mechanism in Netty.
/** * Connects to a server periodically to measure and print the uptime of the * server. This example demonstrates how to implement reliable reconnection * mechanism in Netty. */
public final class UptimeClient { static final String HOST = System.getProperty("host", "127.0.0.1"); static final int PORT = Integer.parseInt(System.getProperty("port", "8080")); // Sleep 5 seconds before a reconnection attempt. static final int RECONNECT_DELAY = Integer.parseInt(System.getProperty("reconnectDelay", "5")); // Reconnect when the server sends nothing for 10 seconds. private static final int READ_TIMEOUT = Integer.parseInt(System.getProperty("readTimeout", "10")); private static final UptimeClientHandler handler = new UptimeClientHandler(); private static final Bootstrap bs = new Bootstrap(); public static void main(String[] args) throws Exception { EventLoopGroup group = new NioEventLoopGroup(); bs.group(group) .channel(NioSocketChannel.class) .remoteAddress(HOST, PORT) .handler(new ChannelInitializer<SocketChannel>() { @Override protected void initChannel(SocketChannel ch) throws Exception { ch.pipeline().addLast(new IdleStateHandler(READ_TIMEOUT, 0, 0), handler); } }); bs.connect(); } static void connect() { bs.connect().addListener(new ChannelFutureListener() { @Override public void operationComplete(ChannelFuture future) throws Exception { if (future.cause() != null) { handler.startTime = -1; handler.println("Failed to connect: " + future.cause()); } } }); } }