Java tutorial
/* * 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 com.cmz.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. */ 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. static final int READ_TIMEOUT = Integer.parseInt(System.getProperty("readTimeout", "10")); private static final UptimeClientHandler handler = new UptimeClientHandler(); public static void main(String[] args) throws Exception { configureBootstrap(new Bootstrap()).connect(); } private static Bootstrap configureBootstrap(Bootstrap b) { return configureBootstrap(b, new NioEventLoopGroup()); } static Bootstrap configureBootstrap(Bootstrap b, EventLoopGroup g) { b.group(g).channel(NioSocketChannel.class).remoteAddress(HOST, PORT) .handler(new ChannelInitializer<SocketChannel>() { @Override public void initChannel(SocketChannel ch) throws Exception { ch.pipeline().addLast(new IdleStateHandler(READ_TIMEOUT, 0, 0), handler); } }); return b; } static void connect(Bootstrap b) { b.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()); } } }); } }