如何在Netty中打開TCP連接（客戶端）？

Question

我一直在看幾個小時的Netty javadocs，我仍然無法弄清楚這一點。如何打開普通的舊TCP連接，例如到Netty的IRC服務器？

Answer 1

you can find many demo in github of netty

Assumeing您正在使用的服務器的netty5。 您應該將解碼器和編碼器添加到您的管線。 像下面

socketChannel.pipeline().addLast(new StringEncoder() ,new StringDecoder() ,new LineBasedFrameDecoder(1024)); 

這裏是我的服務器演示

String ip ; 
int port = 9999; 

NioEventLoopGroup workGroup = new NioEventLoopGroup(8); 
NioEventLoopGroup bossGroup = new NioEventLoopGroup(); 
try { 
    bootstrap = new ServerBootstrap(); 
    bootstrap.group(bossGroup, workGroup); 
    bootstrap.channel(NioServerSocketChannel.class); 
    bootstrap.option(ChannelOption.SO_BACKLOG, 100); 
    bootstrap.childHandler(new ChannelInitializer<SocketChannel>() { 
     @Override 
     protected void initChannel(SocketChannel socketChannel) throws Exception { 
      socketChannel.pipeline().addLast(new StringEncoder() ,new StringDecoder() ,new LineBasedFrameDecoder(1024)); 
      socketChannel.pipeline().addLast(new ChannelHandlerAdapter() { 
       @Override 
       public void channelRegistered(ChannelHandlerContext ctx) throws Exception { 
        System.out.println("the num" +num.getAndIncrement()); 
       } 

       @Override 
       public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 
        System.out.println("what i say is :" + msg.toString()); 
        ctx.channel().writeAndFlush("from server " + "reply message is " +msg.toString()+"\n"); 

       } 
      }); 
     } 
    }); 
    ChannelFuture future = bootstrap.bind(port).sync(); 
    System.out.println("Server start at port : " + port); 
    future.channel().closeFuture().sync(); 
}catch (Exception e){ 
    System.out.println("error"); 
}finally { 
    bossGroup.shutdownGracefully(); 
    workGroup.shutdownGracefully(); 
} 


} 

那麼你可以使用阻塞套接字進行連接正常。 這裏是我的客戶演示。

Socket socket = new Socket(); 
    try { 
     socket.connect(new InetSocketAddress("localhost" , 9999)); 
     InputStream inputStream = socket.getInputStream(); 
     OutputStream outputStream = socket.getOutputStream(); 
     outputStream.write("hello".getBytes()); 
     outputStream.flush(); 
     InputStreamReader reader = new InputStreamReader(inputStream) ; 
     char [] temChar = new char[40]; 
     StringBuffer buffer = new StringBuffer(); 

     while (reader.read(temChar) != -1){ 
      buffer.append(temChar); 
      System.out.println(buffer.toString() +"\n"); 
     } 

    } catch (IOException e) { 
     e.printStackTrace(); 
    } 

然後我發送「你好」，它回覆相同的單詞。

這裏是我的客戶網狀演示

int port = 9999; 
Bootstrap bootstrap ; 
NioEventLoopGroup workGroup = new NioEventLoopGroup(8); 



    try { 
     bootstrap = new Bootstrap(); 
     bootstrap.group(workGroup); 
     bootstrap.channel(NioSocketChannel.class); 
     bootstrap.handler(new ChannelInitializer<SocketChannel>() { 
      @Override 
      protected void initChannel(SocketChannel socketChannel) throws Exception { 
       socketChannel.pipeline().addLast(new StringDecoder() ,new StringEncoder() , new LineBasedFrameDecoder(1024), new ChannelHandlerAdapter(){ 
        @Override 
        public void channelRead(ChannelHandlerContext ctx, Object msg) throws Exception { 
         System.out.println("recieve method of client : " +msg.toString()); 
        } 
       }); 
      } 
     }); 


     NioSocketChannel nioSocketChannel ; 

     ChannelFuture future = bootstrap.connect("localhost" , 9999).sync(); 

     //you can also invoke writeAndFlush() in other thread with channel , 
     // it is the same as server 
     System.out.println("try to write hello"); 
     Channel channel = future.channel(); 
     channel.writeAndFlush("hello\n\r"); 


     future.channel().closeFuture().sync(); //it will block until 
                // you invoke 
                // channel.close(); 




     System.out.println("finish: " + port); 

    }catch (Exception e){ 
     e.printStackTrace(); 
     System.out.println("error"); 
    }finally { 

     workGroup.shutdownGracefully(); 
    } 


}