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

　网络编程 -- RPC实现原理 -- 目录

　　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