六、netty tcp客户端

EventLoopGroup group = new NioEventLoopGroup();
try{
    Bootstrap clientBootstrap = new Bootstrap();

    clientBootstrap.group(group);
    clientBootstrap.channel(NioSocketChannel.class);
    clientBootstrap.remoteAddress(new InetSocketAddress("localhost", 9999));
    clientBootstrap.handler(new ChannelInitializer() {
        protected void initChannel(SocketChannel socketChannel) throws Exception {
            socketChannel.pipeline().addLast(new ClientHandler());
        }
    });
    ChannelFuture channelFuture = clientBootstrap.connect().sync();
    channelFuture.channel().closeFuture().sync();
} finally {
    group.shutdownGracefully().sync();
}

EventLoopGroup group = new NioEventLoopGroup();

Bootstrap clientBootstrap = new Bootstrap();

clientBootstrap.group(group);
clientBootstrap.channel(NioSocketChannel.class);
clientBootstrap.remoteAddress(new InetSocketAddress("localhost", 9999));

clientBootstrap.handler(new ChannelInitializer() {
    protected void initChannel(SocketChannel socketChannel) throws Exception {
        socketChannel.pipeline().addLast(new ClientHandler());
    }
});

ChannelFuture channelFuture = clientBootstrap.connect().sync();

channelFuture.channel().closeFuture().sync();

public class ClientHandler extends SimpleChannelInboundHandler {

    @Override
    public void channelActive(ChannelHandlerContext channelHandlerContext){
        channelHandlerContext.writeAndFlush(Unpooled.copiedBuffer("Netty Rocks!", CharsetUtil.UTF_8));
    }

    @Override
    public void channelRead0(ChannelHandlerContext channelHandlerContext, ByteBuf in) {
        System.out.println("Client received: " + in.toString(CharsetUtil.UTF_8));
    }

    @Override
    public void exceptionCaught(ChannelHandlerContext channelHandlerContext, Throwable cause){
        cause.printStackTrace();
        channelHandlerContext.close();
    }
}