/**
* Copyright (c) 2013 by 苏州科大国创信息技术有限公司.
*/
package com.ustcinfo.netty.client;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.nio.NioSocketChannel;
import java.net.InetSocketAddress;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.ScheduledThreadPoolExecutor;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicInteger;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.alibaba.dubbo.common.utils.NetUtils;
/**
* Create on @2013-8-24 @下午6:48:30
* @author bsli@ustcinfo.com
*/
public class Netty4Client {
private static final Logger logger = LoggerFactory.getLogger(Netty4Client.class);
private String host;
private int port;
private int timeout = 1000;
private int connectTimeout = 3000;
private final EventLoopGroup group = new NioEventLoopGroup();
private ClientChannelInitializer channelInitializer;
private Bootstrap bootstrap;
private volatile Channel channel;
private volatile ChannelFuture future;
private volatile ScheduledFuture<?> reconnectExecutorFuture = null;
private long lastConnectedTime = System.currentTimeMillis();
private final AtomicInteger reconnect_count = new AtomicInteger(0);
private final AtomicBoolean reconnect_error_log_flag = new AtomicBoolean(false) ;
//重连warning的间隔.(waring多少次之后，warning一次)
private final int reconnect_warning_period = 1800;
private final long shutdown_timeout = 1000 * 60 * 15;
private static final ScheduledThreadPoolExecutor reconnectExecutorService = new ScheduledThreadPoolExecutor(2, new NamedThreadFactory("ClientReconnectTimer", true));
public Netty4Client(String host, int port, ClientChannelInitializer channelInitializer) throws Exception {
this.host = host;
this.port = port;
this.channelInitializer = channelInitializer;
try {
doOpen();
} catch (Throwable t) {
close();
throw new Exception("Failed to start " + getClass().getSimpleName() + " " + NetUtils.getLocalAddress()
+ " connect to the server " + host + ", cause: " + t.getMessage(), t);
}
try {
connect();
logger.info("Start " + getClass().getSimpleName() + " " + NetUtils.getLocalAddress() + " connect to the server " + host);
} catch (Throwable t){
throw new Exception("Failed to start " + getClass().getSimpleName() + " " + NetUtils.getLocalAddress()
+ " connect to the server " + host + ", cause: " + t.getMessage(), t);
}
}
public void sendMessage(String message) {
channel.writeAndFlush(message);
}
/*
* 使用时，循环调用该方法获取服务端返回的信息。
* receiveMessage是阻塞方法，如果没有消息会等待。
*/
public String receiveMessage() {
return channelInitializer.getClientHandler().getMessage();
}
private void doOpen() throws Throwable {
bootstrap = new Bootstrap();
bootstrap.option(ChannelOption.SO_KEEPALIVE, true);
bootstrap.option(ChannelOption.TCP_NODELAY, true);
bootstrap.group(group)
.channel(NioSocketChannel.class)
.handler(channelInitializer);
}
private void doConnect() throws Throwable {
long start = System.currentTimeMillis();
future = bootstrap.connect(getConnectAddress());
try{
boolean ret = future.awaitUninterruptibly(getConnectTimeout(), TimeUnit.MILLISECONDS);
if (ret && future.isSuccess()) {
Channel newChannel = future.channel();
try {
// 关闭旧的连接
Channel oldChannel = Netty4Client.this.channel;
if (oldChannel != null) {
logger.info("Close old netty channel " + oldChannel + " on create new netty channel " + newChannel);
oldChannel.close();
}
} finally {
Netty4Client.this.channel = newChannel;
}
} else if (future.cause() != null) {
throw new Exception("client failed to connect to server "
+ getRemoteAddress() + ", error message is:" + future.cause().getMessage(), future.cause());
} else {
throw new Exception("client failed to connect to server "
+ getRemoteAddress() + " client-side timeout "
+ getConnectTimeout() + "ms (elapsed: " + (System.currentTimeMillis() - start) + "ms) from netty client "
+ NetUtils.getLocalHost());
}
}finally{
if (! isConnected()) {
future.cancel(true);
}
}
}
private void connect() throws Exception {
try {
if (isConnected()) {
return;
}
initConnectStatusCheckCommand();
doConnect();
if (! isConnected()) {
throw new Exception("Failed connect to server " + getRemoteAddress() + " from " + getClass().getSimpleName() + " "
+ NetUtils.getLocalHost() + ", cause: Connect wait timeout: " + getTimeout() + "ms.");
} else {
logger.info("Successed connect to server " + getRemoteAddress() + " from " + getClass().getSimpleName() + " "
+ NetUtils.getLocalHost() + ", channel is " + this.channel);
}
reconnect_count.set(0);
reconnect_error_log_flag.set(false);
} catch (Throwable e) {
logger.error("Failed connect to server " + getRemoteAddress() + " from " + getClass().getSimpleName() + " "
+ NetUtils.getLocalHost());
}
}
public void close() {
destroyConnectStatusCheckCommand();
try {
if (channel != null) {
channel.close();
}
} catch (Throwable e) {
logger.warn(e.getMessage(), e);
}
try {
group.shutdownGracefully();
} catch (Throwable t) {
logger.warn(t.getMessage());
}
}
private synchronized void destroyConnectStatusCheckCommand(){
try {
if (reconnectExecutorFuture != null && ! reconnectExecutorFuture.isDone()){
reconnectExecutorFuture.cancel(true);
reconnectExecutorService.purge();
}
} catch (Throwable e) {
logger.warn(e.getMessage(), e);
}
}
public boolean isConnected() {
if (channel == null)
return false;
return channel.isActive();
}
private synchronized void initConnectStatusCheckCommand(){
if(reconnectExecutorFuture == null || reconnectExecutorFuture.isCancelled()){
Runnable connectStatusCheckCommand = new Runnable() {
public void run() {
try {
if (! isConnected()) {
connect();
} else {
lastConnectedTime = System.currentTimeMillis();
}
} catch (Throwable t) {
String errorMsg = "client reconnect to "+getRemoteAddress()+" find error . ";
if (System.currentTimeMillis() - lastConnectedTime > shutdown_timeout){
if (!reconnect_error_log_flag.get()){
reconnect_error_log_flag.set(true);
logger.error(errorMsg, t);
return ;
}
}
if ( reconnect_count.getAndIncrement() % reconnect_warning_period == 0){
logger.warn(errorMsg, t);
}
}
}
};
reconnectExecutorFuture = reconnectExecutorService.scheduleWithFixedDelay(connectStatusCheckCommand, 2 * 1000, 2 * 1000, TimeUnit.MILLISECONDS);
}
}
private InetSocketAddress getConnectAddress() {
return new InetSocketAddress(this.host, this.port);
}
private String getRemoteAddress() {
return host + ":" + port;
}
public int getTimeout() {
return timeout;
}
public int getConnectTimeout() {
return connectTimeout;
}
}