Netty-3-服務端接受並打印telnet傳遞過來的字符串

數據的流通是以byte的形式流通的，本文將通過字節轉換成字符串new String的方式打印出來

第一個handler，首先，往pipeline里加了第二個handler，也就是說，pipeline裏有兩個handler了，handler1負責接收最原始的ByteBuf對象(msg)，似乎對neety來說第一個handler永遠都是ByteBuf，然後將ByteBuf轉換成字符串，打印該字符串，打印完畢之後，將該字符串傳遞到handler2中

public class MyServerHandler1 implements ChannelInboundHandler {
	@Override
	public void handlerAdded(ChannelHandlerContext ctx) throws Exception {
		//動態往pipeline裏添加一個handler
		ctx.pipeline().addLast(new MyServerHandler2());
	}
	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
		//因爲是第一個handler，所以msg是ByteBuf
		ByteBuf bb = (ByteBuf) msg;
		int len = bb.readableBytes();
		byte[] bytes = new byte[len];
		bb.readBytes(bytes);
		String value = new String(bytes);
		System.out.println("channelRead值：" + value);
		//將一個String類型的字符串傳遞給第二個handler
		ctx.fireChannelRead(value);
	}

第二個handler

public class MyServerHandler2 implements ChannelInboundHandler {
	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
		//msg是從handler1中傳遞過來的String類型字符串
		System.out.println(objName + ":channelRead，值：" + msg);
		ctx.fireChannelRead(msg);
	}

main方法

	public static void main(String[] args) throws InterruptedException {
		EventLoopGroup boosGroup = new NioEventLoopGroup();
		EventLoopGroup workerGroup = new NioEventLoopGroup();
		ServerBootstrap b = new ServerBootstrap();
		//此處new MyServerHandler1
		b.group(boosGroup, workerGroup).channel(NioServerSocketChannel.class).childHandler(new MyServerHandler1());
		ChannelFuture f = b.bind(9999).sync();
		f.channel().closeFuture().sync();

啓動main方法，telnet命令，從鍵盤上按哪個字母，控制檯就會打印哪個字母