网络编程 -- RPC实现原理 -- Netty -- 迭代版本V4 -- 粘包拆包

2022-05-14 21:19:59

　　啦啦啦

V2——Netty --

　　new LengthFieldPrepender(2) ：设置数据包 2 字节的特征码

　　new LengthFieldBasedFrameDecoder(65535, 0, 2, 0, 2) ：　65535 ：数据包长度、0：分隔符偏移值、2：分隔符长度、0：数据包偏移值、2：数据包长度。

　　Class ： Server

package lime.pri.limeNio.netty.netty04;

import java.net.InetSocketAddress;

import java.text.SimpleDateFormat;

import java.util.Calendar;

import java.util.Date;

import java.util.List;

import com.alibaba.fastjson.JSON;

import com.alibaba.fastjson.serializer.SerializerFeature;

import io.netty.bootstrap.ServerBootstrap;

import io.netty.buffer.ByteBuf;

import io.netty.buffer.Unpooled;

import io.netty.channel.ChannelFuture;

import io.netty.channel.ChannelFutureListener;

import io.netty.channel.ChannelHandlerAdapter;

import io.netty.channel.ChannelHandlerContext;

import io.netty.channel.ChannelInitializer;

import io.netty.channel.ChannelPipeline;

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.LengthFieldBasedFrameDecoder;

import io.netty.handler.codec.LengthFieldPrepender;

import io.netty.handler.codec.MessageToMessageCodec;

import io.netty.util.CharsetUtil;

import lime.pri.limeNio.netty.netty03.entity.User;

public class Server {

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

        ServerBootstrap serverBootstrap = new ServerBootstrap();

        EventLoopGroup boss = new NioEventLoopGroup();

        EventLoopGroup worker = new NioEventLoopGroup();

        serverBootstrap.group(boss, worker);

        serverBootstrap.channel(NioServerSocketChannel.class);

        serverBootstrap.childHandler(new ChannelInitializer<SocketChannel>() {

            @Override

            protected void initChannel(SocketChannel ch) throws Exception {

                ChannelPipeline pipeline = ch.pipeline();

                pipeline.addLast(new LengthFieldPrepender(2))

                        .addLast(new LengthFieldBasedFrameDecoder(65535, 0, 2, 0, 2))

                        .addLast(new MessageToMessageCodec<ByteBuf, Object>() {

                            @Override

                            protected void encode(ChannelHandlerContext ctx, Object msg, List<Object> out)

                                    throws Exception {

                                out.add(Unpooled.buffer().writeBytes(JSON.toJSONString(msg,SerializerFeature.WriteClassName).getBytes(CharsetUtil.UTF_8)));

                            }

                            @Override

                            protected void decode(ChannelHandlerContext ctx, ByteBuf msg, List<Object> out)

                                    throws Exception {

                                out.add(JSON.parse(msg.toString(CharsetUtil.UTF_8)));

                            }

                        }).addLast(new ChannelHandlerAdapter() {

                            @Override

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

                                System.out.println("客户端(" + ctx.channel().remoteAddress() + ") 请求数据：" + msg);

                                ChannelFuture channelFuture = null;

                                String request = (String) msg;

                                Calendar calendar = Calendar.getInstance();

                                if("Query Date".equalsIgnoreCase(request)){

                                    for (int i = 1; i < 10; i++) {

                                        calendar.set(Calendar.DAY_OF_MONTH, i);

                                        channelFuture = ctx.writeAndFlush("当前系统时间：" + new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(calendar.getTime()));

                                    }

                                }else if("Query User".equalsIgnoreCase(request)){

                                    for (int i = 1; i < 10; i++) {

                                        channelFuture = ctx.writeAndFlush(new User(i,"lime_" + i,new Date()));

                                    }

                                }else{

                                    channelFuture = ctx.writeAndFlush("请求参数不正确");

                                }

                                channelFuture.addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);

                                channelFuture.addListener(ChannelFutureListener.CLOSE_ON_FAILURE);

                                channelFuture.addListener(ChannelFutureListener.CLOSE);

                            }

                            @Override

                            public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {

                                System.out.println(cause);

                            }

                        });

            }

        });

        ChannelFuture channelFuture = serverBootstrap.bind(new InetSocketAddress(9999)).sync();

        channelFuture.channel().closeFuture().sync();

        boss.close();

        worker.close();

    }

}

　　Class ： Client

package lime.pri.limeNio.netty.netty04;

import java.net.InetSocketAddress;

import java.util.List;

import com.alibaba.fastjson.JSON;

import com.alibaba.fastjson.serializer.SerializerFeature;

import io.netty.bootstrap.Bootstrap;

import io.netty.buffer.ByteBuf;

import io.netty.buffer.Unpooled;

import io.netty.channel.ChannelFuture;

import io.netty.channel.ChannelHandlerAdapter;

import io.netty.channel.ChannelHandlerContext;

import io.netty.channel.ChannelInitializer;

import io.netty.channel.ChannelPipeline;

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.LengthFieldBasedFrameDecoder;

import io.netty.handler.codec.LengthFieldPrepender;

import io.netty.handler.codec.MessageToMessageCodec;

import io.netty.util.CharsetUtil;

public class Client {

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

        for (int i = 0; i < 1; i++) {

            new Thread() {

                {

                    setDaemon(false);

                }

                public void run() {

                    try {

                        client();

                    } catch (Exception e) {

                        e.printStackTrace();

                    }

                };

            }.start();

        }

    }

    private static void client() throws Exception {

        Bootstrap bootstrap = new Bootstrap();

        EventLoopGroup worker = new NioEventLoopGroup();

        bootstrap.group(worker);

        bootstrap.channel(NioSocketChannel.class);

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

            @Override

            protected void initChannel(SocketChannel ch) throws Exception {

                ChannelPipeline pipeline = ch.pipeline();

                pipeline.addLast(new LengthFieldPrepender(2))

                        .addLast(new LengthFieldBasedFrameDecoder(65535, 0, 2, 0, 2))

                        .addLast(new MessageToMessageCodec<ByteBuf, Object>() {

                            @Override

                            protected void encode(ChannelHandlerContext ctx, Object msg, List<Object> out)

                                    throws Exception {

                                out.add(Unpooled.buffer().writeBytes(JSON.toJSONString(msg,SerializerFeature.WriteClassName).getBytes(CharsetUtil.UTF_8)));

                            }

                            @Override

                            protected void decode(ChannelHandlerContext ctx, ByteBuf msg, List<Object> out)

                                    throws Exception {

                                out.add(JSON.parse(msg.toString(CharsetUtil.UTF_8)));

                            }

                        }).addLast(new ChannelHandlerAdapter() {

                            /**

                             * 默认只捕获网络连接异常

                             */

                            @Override

                            public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {

                                System.out.println(cause);

                            }

                            /**

                             * 客户端发送经过JSON编码的byteBuf

                             */

                            @Override

                            public void channelActive(ChannelHandlerContext ctx) throws Exception {

                                String request = null;

                                switch (0) {

                                case 0:

                                    request = "Query Date";

                                    break;

                                case 1:

                                    request = "Query User";

                                    break;

                                default:

                                    request = "Query What?";

                                    break;

                                }

                                ctx.writeAndFlush(request);

                            }

                            @Override

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

                                System.out.println("当前线程：" + Thread.currentThread() + " 服务端响应数据 --> " + msg);

                            }

                        });

            }

        });

        ChannelFuture channelFuture;

        channelFuture = bootstrap.connect(new InetSocketAddress(9999)).sync();

        channelFuture.channel().closeFuture().sync();

        worker.close();

    }

}

　　Console： Server

客户端(/192.168.229.1:6280) 请求数据：Query Date

　　Console ： Client

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-01 21:42:08

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-02 21:42:08

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-03 21:42:08

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-04 21:42:08

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-05 21:42:08

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-06 21:42:08

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-07 21:42:08

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-08 21:42:08

当前线程：Thread[nioEventLoopGroup-0-1,10,main] 服务端响应数据 --> 当前系统时间：2017-06-09 21:42:08

啦啦啦

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