网络编程之每天学习一点点[day8]-----netty之tcp拆包粘包解决方案一“固定分割符”

很简单，直接上代码

import io.netty.bootstrap.ServerBootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
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;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;

public class Server {

	public static void main(String[] args) throws Exception{
		//1 创建2个线程，一个是负责接收客户端的连接。一个是负责进行数据传输的
		EventLoopGroup pGroup = new NioEventLoopGroup();
		EventLoopGroup cGroup = new NioEventLoopGroup();
		
		//2 创建服务器辅助类
		ServerBootstrap b = new ServerBootstrap();
		b.group(pGroup, cGroup)
		 .channel(NioServerSocketChannel.class)
		 .option(ChannelOption.SO_BACKLOG, 1024)
		 .option(ChannelOption.SO_SNDBUF, 32*1024)
		 .option(ChannelOption.SO_RCVBUF, 32*1024)
		 .childHandler(new ChannelInitializer<SocketChannel>() {
			@Override
			protected void initChannel(SocketChannel sc) throws Exception {
				//设置特殊分隔符
				ByteBuf buf = Unpooled.copiedBuffer("$_".getBytes());
				sc.pipeline().addLast(new DelimiterBasedFrameDecoder(1024, buf));
				//设置字符串形式的解码 发来的消息会变成字符串形式
				sc.pipeline().addLast(new StringDecoder());
				//注意处理器的先后顺序 最后才是我们自定义的服务器业务处理类
				sc.pipeline().addLast(new ServerHandler());
			}
		});
		
		//4 绑定连接
		ChannelFuture cf = b.bind(8765).sync();
		
		//等待服务器监听端口关闭
		cf.channel().closeFuture().sync();
		pGroup.shutdownGracefully();
		cGroup.shutdownGracefully();
		
	}
	
}

ServerHandler：

import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;

public class ServerHandler extends ChannelHandlerAdapter {


	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		System.out.println(" server channel active... ");
	}

	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
		String request = (String)msg;
		System.out.println("Server :" + request);
		//响应的数据也要加上分割符
		String response = "服务器响应：" + msg + "$_";
		//不能直接返回response字符串，还是得bytebuffer
		ctx.writeAndFlush(Unpooled.copiedBuffer(response.getBytes()));
	}

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

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

}

Client

import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
import io.netty.handler.codec.DelimiterBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;

public class Client {

	public static void main(String[] args) throws Exception {
		
		EventLoopGroup group = new NioEventLoopGroup();
		
		Bootstrap b = new Bootstrap();
		b.group(group)
		 .channel(NioSocketChannel.class)
		 .handler(new ChannelInitializer<SocketChannel>() {
			@Override
			protected void initChannel(SocketChannel sc) throws Exception {
				//接收服务器发送的数据 以固定分割符来解析
				ByteBuf buf = Unpooled.copiedBuffer("$_".getBytes());
				sc.pipeline().addLast(new DelimiterBasedFrameDecoder(1024, buf));
				sc.pipeline().addLast(new StringDecoder());
				sc.pipeline().addLast(new ClientHandler());
			}
		});
		
		ChannelFuture cf = b.connect("127.0.0.1", 8765).sync();
		//向服务器发送数据以$_为分割符
		cf.channel().writeAndFlush(Unpooled.wrappedBuffer("bbbb$_".getBytes()));
		cf.channel().writeAndFlush(Unpooled.wrappedBuffer("cccc$_".getBytes()));
		
		//等待客户端端口关闭
		cf.channel().closeFuture().sync();
		group.shutdownGracefully();
		
	}
}

ClientHandler

import io.netty.channel.ChannelHandlerAdapter;
import io.netty.channel.ChannelHandlerContext;
import io.netty.util.ReferenceCountUtil;

public class ClientHandler extends ChannelHandlerAdapter{

	//通道刚被激活方法处理
	@Override
	public void channelActive(ChannelHandlerContext ctx) throws Exception {
		System.out.println("client channel active... ");
	}

	@Override
	public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception {
		try {
			String response = (String)msg;
			System.out.println("Client: " + response);
		} finally {
			ReferenceCountUtil.release(msg);
		}
	}

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

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

}

打印：

Server端：

Client端：

可以看到已经分开了！两次独立的数据请求和响应！