netty client 连接超时设置

public class Client4 {

    public static void main(String[] args) {

        //worker负责读写数据
        EventLoopGroup worker = new NioEventLoopGroup();
        long st = System.currentTimeMillis();

        try {
            //辅助启动类
            Bootstrap bootstrap = new Bootstrap();

            //设置线程池
            bootstrap.group(worker);

            //设置socket工厂
            bootstrap.channel(NioSocketChannel.class);

            /**
             * *******************************************************************
             * 如果不设置超时，连接会一直占用本地线程，端口，连接客户端一多，会导致本地端口用尽及CPU压力
             */
            bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000);

            //设置管道
            bootstrap.handler(new ChannelInitializer<SocketChannel>() {
                @Override
                protected void initChannel(SocketChannel socketChannel) throws Exception {
                    //获取管道
                    ChannelPipeline pipeline = socketChannel.pipeline();
                    pipeline.addLast(new LengthFieldBasedFrameDecoder(10000, 0, 4, 0, 4));
                    pipeline.addLast(new ProtobufDecoder(MyBaseProto.BaseProto.getDefaultInstance()));
                    pipeline.addLast(new LengthFieldPrepender(4));
                    pipeline.addLast(new ProtobufEncoder());

                    pipeline.addLast(new IdleStateHandler(61, 30, 0, TimeUnit.SECONDS));
                    pipeline.addLast(new ClientHeartbeatHandler());

                    //处理类
                    pipeline.addLast(new ClientHandler4Heart());
                }
            });

            //发起异步连接操作（

// 如果是127.0.0.1，则会直接抛连接异常，由于192。*网络不通，故到时抛超时异常

）

            ChannelFuture futrue = bootstrap.connect(new InetSocketAddress("192.168.1.1",8866)).sync();

            //等待客户端链路关闭
            futrue.channel().closeFuture().sync();
        } catch (Exception e) {
            e.printStackTrace();
            long ed = System.currentTimeMillis();
            System.out.println((ed-st)/1000);
        } finally {
            //优雅的退出，释放NIO线程组
            worker.shutdownGracefully();
        }
    }

}

/**
 * *******************************************************************
 * 如果不设置超时，连接会一直占用本地线程，端口，连接客户端一多，阻塞在那里，会导致本地端口用尽及CPU压力
 */
bootstrap.option(ChannelOption.CONNECT_TIMEOUT_MILLIS, 5000);

未设置超时：

30
io.netty.channel.ConnectTimeoutException: connection timed out: /192.168.1.1:8866
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe$1.run(AbstractNioChannel.java:206)
at io.netty.util.concurrent.PromiseTask$RunnableAdapter.call(PromiseTask.java:38)
at io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:123)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:354)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:353)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101)
at java.lang.Thread.run(Thread.java:745)

Process finished with exit code 0

设置后：

5
io.netty.channel.ConnectTimeoutException: connection timed out: /192.168.1.1:8866
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe$1.run(AbstractNioChannel.java:206)
at io.netty.util.concurrent.PromiseTask$RunnableAdapter.call(PromiseTask.java:38)
at io.netty.util.concurrent.ScheduledFutureTask.run(ScheduledFutureTask.java:123)
at io.netty.util.concurrent.SingleThreadEventExecutor.runAllTasks(SingleThreadEventExecutor.java:354)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:353)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101)
at java.lang.Thread.run(Thread.java:745)

Process finished with exit code 0

192.*这个ip由于网络不通，触发的是超时异常，如果是网络通的，但是服务不通，则会

java.net.ConnectException: Connection refused: /127.0.0.1:8866
0
at sun.nio.ch.SocketChannelImpl.checkConnect(Native Method)
at sun.nio.ch.SocketChannelImpl.finishConnect(SocketChannelImpl.java:717)
at io.netty.channel.socket.nio.NioSocketChannel.doFinishConnect(NioSocketChannel.java:191)
at io.netty.channel.nio.AbstractNioChannel$AbstractNioUnsafe.finishConnect(AbstractNioChannel.java:279)
at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:511)
at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:461)
at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:378)
at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:350)
at io.netty.util.concurrent.SingleThreadEventExecutor$2.run(SingleThreadEventExecutor.java:101)
at java.lang.Thread.run(Thread.java:745)

Process finished with exit code 0

立马抛出异常，ConnectException非超时异常