请问Netty5客户端怎么主动给服务端发消息？

笨鸟先飞_ 2016-04-15 05:36:25

服务端



import io.netty.bootstrap.ServerBootstrap;



import io.netty.channel.ChannelFuture;

import io.netty.channel.ChannelInitializer;

import io.netty.channel.ChannelOption;

import io.netty.channel.EventLoopGroup;

import io.netty.channel.nio.NioEventLoopGroup;

import io.netty.channel.socket.SocketChannel;

import io.netty.channel.socket.nio.NioServerSocketChannel;



public class NettyServer {

	private int port;



	public NettyServer(int port) {

		this.port = port;

	}



	public void run() throws Exception {

		EventLoopGroup bossGroup = new NioEventLoopGroup(); // (1)

		EventLoopGroup workerGroup = new NioEventLoopGroup();

		try {

			ServerBootstrap b = new ServerBootstrap(); // (2)

			b.group(bossGroup, workerGroup).channel(NioServerSocketChannel.class) // (3)

					.childHandler(new ChannelInitializer<SocketChannel>() { // (4)

						@Override

						public void initChannel(SocketChannel ch) throws Exception {

							ch.pipeline().addLast(new NettyServerHandler());

						}

					}).option(ChannelOption.SO_BACKLOG, 128) // (5)

					.childOption(ChannelOption.SO_KEEPALIVE, true); // (6)



			// Bind and start to accept incoming connections.

			ChannelFuture f = b.bind(port).sync(); // (7)



			// Wait until the server socket is closed.

			// In this example, this does not happen, but you can do that to

			// gracefully

			// shut down your server.

			f.channel().closeFuture().sync();

		} finally {

			workerGroup.shutdownGracefully();

			bossGroup.shutdownGracefully();

		}

	}



	public static void main(String[] args) throws Exception {

		int port;

		if (args.length > 0) {

			port = Integer.parseInt(args[0]);

		} else {

			port = 8080;

		}

		new NettyServer(port).run();

	}

}

服务端消息处理



import io.netty.channel.ChannelFuture;

import io.netty.channel.ChannelFutureListener;

import io.netty.channel.ChannelHandlerAdapter;



import java.nio.charset.Charset;



import io.netty.buffer.ByteBuf;



import io.netty.channel.ChannelHandlerContext;

import io.netty.util.ReferenceCountUtil;



public class NettyServerHandler extends ChannelHandlerAdapter {

	@Override

	public void channelRead(ChannelHandlerContext ctx, Object msg) { // (2)

		

		//接收

		ByteBuf in = (ByteBuf) msg;

	    try {

	    	

	    	System.out.println(in.toString(io.netty.util.CharsetUtil.UTF_8));

//	        while (in.isReadable()) { // (1)

//	            System.out.print((char) in.readByte());

//	            System.out.flush();

//	        }

	    } finally {

	        ReferenceCountUtil.release(msg); // (2)

	    }

		//发送

		ctx.write("这是服务端".getBytes(Charset.forName("UTF-8"))); // (1)

        ctx.flush(); // (2)

	}



	@Override

    public void channelActive(final ChannelHandlerContext ctx) { // (1)

        final ByteBuf buff = ctx.alloc().buffer(64); // (2)

        buff.writeBytes("欢迎光临".getBytes(Charset.forName("UTF-8")));



        final ChannelFuture f = ctx.writeAndFlush(buff); 

        f.addListener(new ChannelFutureListener() {

            public void operationComplete(ChannelFuture future) {

                assert f == future;

                ctx.close();

            }

        }); 

    }

	

	@Override

	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) { // (4)

		// Close the connection when an exception is raised.

		cause.printStackTrace();

		ctx.close();

	}

}

客户端



import io.netty.bootstrap.Bootstrap;



import io.netty.channel.ChannelFuture;

import io.netty.channel.ChannelHandlerContext;

import io.netty.channel.ChannelInitializer;

import io.netty.channel.ChannelOption;

import io.netty.channel.EventLoopGroup;

import io.netty.channel.nio.NioEventLoopGroup;

import io.netty.channel.socket.SocketChannel;

import io.netty.channel.socket.nio.NioSocketChannel;



public class NettyClient {









	

	public static void main(String[] args) throws Exception {

		String host = "127.0.0.1";

		int port = 8080;

		EventLoopGroup workerGroup = new NioEventLoopGroup();



		try {

			Bootstrap b = new Bootstrap(); // (1)

			b.group(workerGroup); // (2)

			b.channel(NioSocketChannel.class); // (3)

			b.option(ChannelOption.SO_KEEPALIVE, true); // (4)

			b.handler(new ChannelInitializer<SocketChannel>() {

				@Override

				public void initChannel(SocketChannel ch) throws Exception {

					ch.pipeline().addLast(new NettyClientHandler());

				}

			});



			// Start the client.

			ChannelFuture f = b.connect(host, port).sync(); // (5)



			// Wait until the connection is closed.

			f.channel().closeFuture().sync();



		} finally {

			workerGroup.shutdownGracefully();

		}

	}

}

客户端消息处理





import io.netty.buffer.ByteBuf;

import io.netty.channel.ChannelHandlerAdapter;

import io.netty.channel.ChannelHandlerContext;



import java.nio.charset.Charset;





public class NettyClientHandler extends ChannelHandlerAdapter {

	@Override

	public void channelRead(ChannelHandlerContext ctx, Object msg) {

		try {

			//虽然这里可以给服务端发消息但是我想在其他地方需要发消息的时候再发而不是收到服务端发来消息才发

			ByteBuf buf = (ByteBuf)msg;

			System.out.println(buf.toString(Charset.forName("UTF-8")));

			ctx.close();

		} finally {

		}

	}



	@Override

	public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {

		cause.printStackTrace();

		ctx.close();

	}

}