JavaTCP粘包、拆包

import java.nio.ByteBuffer;
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.FixedLengthFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

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
				sc.pipeline().addLast(new StringDecoder());
				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();

	}
}

　　

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.FixedLengthFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import io.netty.handler.codec.string.StringEncoder;

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 {
				//
				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();

		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();

	}
}

　　

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 :" + msg);
		String response = "服务器响应：" + msg + "$_";
		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();
	}
}

　　

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

public class ClientHandler extends ChannelHandlerAdapter{

	@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();
	}

}

　　

import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandler;
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.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.timeout.ReadTimeoutHandler;

public class Server {
    public Server() {
    }

    public static void main(String[] args) throws Exception {
        EventLoopGroup pGroup = new NioEventLoopGroup();
        EventLoopGroup cGroup = new NioEventLoopGroup();
        ServerBootstrap b = new ServerBootstrap();
        ((ServerBootstrap)((ServerBootstrap)((ServerBootstrap)b.group(pGroup, cGroup).channel(NioServerSocketChannel.class)).option(ChannelOption.SO_BACKLOG, 1024)).handler(new LoggingHandler(LogLevel.INFO))).childHandler(new ChannelInitializer<SocketChannel>() {
            protected void initChannel(SocketChannel sc) throws Exception {
                sc.pipeline().addLast(new ChannelHandler[]{MarshallingCodeCFactory.buildMarshallingDecoder()});
                sc.pipeline().addLast(new ChannelHandler[]{MarshallingCodeCFactory.buildMarshallingEncoder()});
                sc.pipeline().addLast(new ChannelHandler[]{new ReadTimeoutHandler(5)});
                sc.pipeline().addLast(new ChannelHandler[]{new ServerHandler()});
            }
        });
        ChannelFuture cf = b.bind(8765).sync();
        cf.channel().closeFuture().sync();
        pGroup.shutdownGracefully();
        cGroup.shutdownGracefully();
    }
}

　　

import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandler;
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.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.timeout.ReadTimeoutHandler;
import java.util.concurrent.TimeUnit;

public class Client {
    private EventLoopGroup group;
    private Bootstrap b;
    private ChannelFuture cf;

    public static Client getInstance() {
        return Client.SingletonHolder.instance;
    }

    private Client() {
        this.group = new NioEventLoopGroup();
        this.b = new Bootstrap();
        ((Bootstrap)((Bootstrap)((Bootstrap)this.b.group(this.group)).channel(NioSocketChannel.class)).handler(new LoggingHandler(LogLevel.INFO))).handler(new ChannelInitializer<SocketChannel>() {
            protected void initChannel(SocketChannel sc) throws Exception {
                sc.pipeline().addLast(new ChannelHandler[]{MarshallingCodeCFactory.buildMarshallingDecoder()});
                sc.pipeline().addLast(new ChannelHandler[]{MarshallingCodeCFactory.buildMarshallingEncoder()});
                sc.pipeline().addLast(new ChannelHandler[]{new ReadTimeoutHandler(5)});
                sc.pipeline().addLast(new ChannelHandler[]{new ClientHandler()});
            }
        });
    }

    public void connect() {
        try {
            this.cf = this.b.connect("127.0.0.1", 8765).sync();
            System.out.println("远程服务器已经连接, 可以进行数据交换..");
        } catch (Exception var2) {
            var2.printStackTrace();
        }

    }

    public ChannelFuture getChannelFuture() {
        if (this.cf == null) {
            this.connect();
        }

        if (!this.cf.channel().isActive()) {
            this.connect();
        }

        return this.cf;
    }

    public static void main(String[] args) throws Exception {
        final Client c = getInstance();
        ChannelFuture cf = c.getChannelFuture();

        for(int i = 1; i <= 3; ++i) {
            Request request = new Request();
            request.setId("" + i);
            request.setName("pro" + i);
            request.setRequestMessage("数据信息" + i);
            cf.channel().writeAndFlush(request);
            TimeUnit.SECONDS.sleep(4L);
        }

        cf.channel().closeFuture().sync();
        (new Thread(new Runnable() {
            public void run() {
                try {
                    System.out.println("进入子线程...");
                    ChannelFuture cf = c.getChannelFuture();
                    System.out.println(cf.channel().isActive());
                    System.out.println(cf.channel().isOpen());
                    Request request = new Request();
                    request.setId("4");
                    request.setName("pro4");
                    request.setRequestMessage("数据信息4");
                    cf.channel().writeAndFlush(request);
                    cf.channel().closeFuture().sync();
                    System.out.println("子线程结束.");
                } catch (InterruptedException var3) {
                    var3.printStackTrace();
                }

            }
        })).start();
        System.out.println("断开连接,主线程结束..");
    }

    private static class SingletonHolder {
        static final Client instance = new Client((Client)null);

        private SingletonHolder() {
        }
    }
}