基于Netty实现的简易服务端与客户端的信息交流

1：服务器端所需要的三个类如下：

public class TimeServer {

	public static void main(String[] agrs) {
		new TimeServer().bind(8080);
	}

	private void bind(int port) {
		EventLoopGroup bossGroup = new NioEventLoopGroup();
		EventLoopGroup workerGroup = new NioEventLoopGroup();

		try {
			ServerBootstrap sb = new ServerBootstrap();
			sb.group(bossGroup, workerGroup)
			.channel(NioServerSocketChannel.class)
			.option(ChannelOption.SO_BACKLOG, 1024)
			.childHandler(new ChildChannelHandler());
			ChannelFuture f = sb.bind(port).sync();
			f.channel().closeFuture().sync();
		} catch (InterruptedException e) {
			bossGroup.shutdownGracefully();
			workerGroup.shutdownGracefully();
			e.printStackTrace();
		}
	}
}

public class ChildChannelHandler extends ChannelInitializer<SocketChannel> {

	@Override
	protected void initChannel(SocketChannel channel) throws Exception {
		channel.pipeline().addLast(new TimeServerHandler());
	}
}

public class TimeServerHandler extends ChannelInboundHandlerAdapter {

	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
		ByteBuf bfBuf = (ByteBuf) msg;
		byte[] bytes = new byte[bfBuf.readableBytes()];
		bfBuf.readBytes(bytes);

		String message = new String(bytes,"UTF-8");
		System.out.println("the requestMessage is："+message);

		ByteBuf responseBuffer = Unpooled.copiedBuffer("the response message from server".getBytes());
		ctx.write(responseBuffer);
	}

	@Override
	public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
		ctx.flush();
	}

	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause)
			throws Exception {
		ctx.close();
	}
}

2：客户端实现了两个类

public class TimeClient {

	public static void main(String[] args) {
		new TimeClient().connect("127.0.0.1",8080);
	}

	private void connect(String ip, int port) {

		EventLoopGroup group = new NioEventLoopGroup();

		try {
			Bootstrap bs = new Bootstrap();
			bs.group(group)
			.channel(NioSocketChannel.class)
			.option(ChannelOption.TCP_NODELAY, true)
			.handler(new ChannelInitializer<SocketChannel>() {
				@Override
				protected void initChannel(SocketChannel ch) throws Exception {
					ch.pipeline().addLast(new TimeClientHandler());
				}
			});

			ChannelFuture cf = bs.connect(ip,port).sync();
			cf.channel().closeFuture().sync();
		} catch (InterruptedException e) {
			e.printStackTrace();
		} finally {
			group.shutdownGracefully();
		}
	}
}

public class TimeClientHandler extends ChannelInboundHandlerAdapter {

	private final ByteBuf buffer;

	public TimeClientHandler () {
		String message = "quest message";
		buffer = Unpooled.buffer(message.length());
		buffer.writeBytes(message.getBytes());
	}

	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		ctx.writeAndFlush(buffer);
	}


	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {

		ByteBuf responseMessage = (ByteBuf) msg;
		byte[] bytes = new byte[responseMessage.readableBytes()];
		responseMessage.readBytes(bytes);

		String resMsg = new String(bytes, "UTF-8");
		System.out.println(resMsg);
	}

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