（二）Netty基础操作案例

女爷i 2022-01-26 15:49 186阅读 0赞

Netty网络聊天室：

ChatClient 网络聊天室客户端

package com.bestqiang.netty.chat;
    
    import io.netty.bootstrap.Bootstrap;
    import io.netty.channel.*;
    import io.netty.channel.nio.NioEventLoopGroup;
    import io.netty.channel.socket.SocketChannel;
    import io.netty.channel.socket.nio.NioSocketChannel;
    import io.netty.handler.codec.string.StringDecoder;
    import io.netty.handler.codec.string.StringEncoder;
    
    import java.util.Scanner;
    
    //聊天程序客户端
    public class ChatClient { 
        private final String host; //服务器端IP地址
        private final int port;  //服务器端端口号
    
        public ChatClient(String host, int port) { 
            this.host = host;
            this.port = port;
        }
    
        public void run(){ 
            EventLoopGroup group = new NioEventLoopGroup();
            try { 
                Bootstrap bootstrap = new Bootstrap()
                        .group(group)
                        .channel(NioSocketChannel.class)
                        .handler(new ChannelInitializer<SocketChannel>() { 
                            @Override
                            public void initChannel(SocketChannel ch){ 
                                ChannelPipeline pipeline=ch.pipeline();
                                //往pipeline链中添加一个解码器
                                pipeline.addLast("decoder",new StringDecoder());
                                //往pipeline链中添加一个编码器
                                pipeline.addLast("encoder",new StringEncoder());
                                //往pipeline链中添加自定义的handler(业务处理类)
                                pipeline.addLast(new ChatClientHandler());
                            }
                        });
    
                ChannelFuture cf=bootstrap.connect(host,port).sync();
                Channel channel=cf.channel();
                System.out.println("------"+channel.localAddress().toString().substring(1)+"------");
                Scanner scanner=new Scanner(System.in);
                while (scanner.hasNextLine()){ 
                    String msg=scanner.nextLine();
                    channel.writeAndFlush(msg+"\r\n");
                }
            } catch (Exception e) { 
                e.printStackTrace();
            } finally { 
                group.shutdownGracefully();
            }
        }
    
        public static void main(String[] args) throws Exception { 
            new ChatClient("127.0.0.1",9999).run();
        }
    }

网络聊天室服务器端：

package com.bestqiang.netty.chat;
    
    import io.netty.bootstrap.ServerBootstrap;
    import io.netty.channel.*;
    import io.netty.channel.nio.NioEventLoopGroup;
    import io.netty.channel.socket.SocketChannel;
    import io.netty.channel.socket.nio.NioServerSocketChannel;
    import io.netty.handler.codec.string.StringDecoder;
    import io.netty.handler.codec.string.StringEncoder;
    
    //聊天程序服务器端
    public class ChatServer { 
    
        private int port; //服务器端端口号
    
        public ChatServer(int port) { 
            this.port = port;
        }
    
        public void run() throws Exception { 
            EventLoopGroup bossGroup = new NioEventLoopGroup();
            EventLoopGroup workerGroup = new NioEventLoopGroup();
            try { 
                ServerBootstrap b = new ServerBootstrap();
                b.group(bossGroup, workerGroup)
                        .channel(NioServerSocketChannel.class)
                        .option(ChannelOption.SO_BACKLOG, 128)
                        .childOption(ChannelOption.SO_KEEPALIVE, true)
                        .childHandler(new ChannelInitializer<SocketChannel>() { 
                            @Override
                            public void initChannel(SocketChannel ch) { 
                                ChannelPipeline pipeline=ch.pipeline();
                                //往pipeline链中添加一个解码器
                                pipeline.addLast("decoder",new StringDecoder());
                                //往pipeline链中添加一个编码器
                                pipeline.addLast("encoder",new StringEncoder());
                                //往pipeline链中添加自定义的handler(业务处理类)
                                pipeline.addLast(new ChatServerHandler());
            }
        });
                System.out.println("Netty Chat Server启动......");
        ChannelFuture f = b.bind(port).sync();
                f.channel().closeFuture().sync();
            } finally { 
                workerGroup.shutdownGracefully();
                bossGroup.shutdownGracefully();
                System.out.println("Netty Chat Server关闭......");
            }
        }
    
        public static void main(String[] args) throws Exception { 
            new ChatServer(9999).run();
        }
    }

客户端业务处理类：

package com.bestqiang.netty.chat;
    
    import io.netty.channel.ChannelHandlerContext;
    import io.netty.channel.SimpleChannelInboundHandler;
    
    //自定义一个客户端业务处理类
    public class ChatClientHandler extends SimpleChannelInboundHandler<String> { 
        @Override
        protected void channelRead0(ChannelHandlerContext ctx, String s) throws Exception { 
            System.out.println(s.trim());
        }
    }

服务器端业务处理类：

package com.bestqiang.netty.chat;
    
    import io.netty.channel.Channel;
    import io.netty.channel.ChannelHandlerContext;
    import io.netty.channel.SimpleChannelInboundHandler;
    import io.netty.channel.group.ChannelGroup;
    import io.netty.channel.group.DefaultChannelGroup;
    import io.netty.util.concurrent.GlobalEventExecutor;
    
    import java.util.ArrayList;
    import java.util.List;
    
    //自定义一个服务器端业务处理类
    public class ChatServerHandler extends SimpleChannelInboundHandler<String> { 
    
        public static List<Channel> channels = new ArrayList<>();
    
        @Override  //通道就绪
        public void channelActive(ChannelHandlerContext ctx)  { 
            Channel inChannel=ctx.channel();
            channels.add(inChannel);
            System.out.println("[Server]:"+inChannel.remoteAddress().toString().substring(1)+"上线");
        }
        @Override  //通道未就绪
        public void channelInactive(ChannelHandlerContext ctx)  { 
            Channel inChannel=ctx.channel();
            channels.remove(inChannel);
            System.out.println("[Server]:"+inChannel.remoteAddress().toString().substring(1)+"离线");
        }
        @Override  //读取数据
        protected void channelRead0(ChannelHandlerContext ctx, String s)  { 
            Channel inChannel=ctx.channel();
            for(Channel channel:channels){ 
                if(channel!=inChannel){ 
                    channel.writeAndFlush("["+inChannel.remoteAddress().toString().substring(1)+"]"+"说："+s+"\n");
                }
            }
        }
    
    }