Netty基本组件

忘是亡心i 2022-12-28 12:57 215阅读 0赞

### 1 Netty是什么 ###

*  异步事件驱动框架，用于快速开发高性能服务端和客户端
 *  封装了JDK底层BIO和NIO模型，提供高度可用的API
 *  自带编解码器解决拆包粘包问题，用户只用关心业务逻辑
 *  精心设计的reactor线程模型支持高并发海量连接
 *  自带各种协议栈让你处理任何一种通信协议都几乎不用亲自动手

### 2 一个简单的socket例子 ###

这是一个简单I/O的例子

/** * Server端启动类 * @author mazhen */
    public class ServerBoot { 
    
        private static final int PORT = 10000;
    
        public static void main(String[] args) { 
            Server server = new Server(PORT);
            server.start();
        }
    
    }

import java.io.IOException;
    import java.net.ServerSocket;
    import java.net.Socket;
    
    public class Server { 
    
        private ServerSocket serverSocket;
    
        public Server(int port) { 
            try { 
                this.serverSocket = new ServerSocket(port);
                System.out.println("服务端启动成功，端口:" + port);
            } catch (IOException exception) { 
                System.out.println("服务端启动失败");
            }
        }
    
        public void start() { 
            doStart();
    
            System.out.println("无法执行到我?");
        }
    
        private void doStart() { 
            while (true) { 
                try { 
                    //serverSocket获取客户端的请求并获取客户端Socket
                    Socket client = serverSocket.accept();
                    new ClientHandler(client).start();
                } catch (IOException e) { 
                    System.out.println("服务端异常");
                }
            }
        }
    }

import java.io.IOException;
    import java.io.InputStream;
    import java.net.Socket;
    
    public class ClientHandler { 
    
        public static final int MAX_DATA_LEN = 1024;
        private final Socket socket;
    
        public ClientHandler(Socket socket) { 
            this.socket = socket;
        }
    
        public void start() { 
            System.out.println("新客户端接入");
            //启动一个线程，读取Socket中的输入流
            new Thread(this::doStart).start();
        }
    
        private void doStart() { 
            try { 
                InputStream inputStream = socket.getInputStream();
                while (true) { 
                    byte[] data = new byte[MAX_DATA_LEN];
                    int len;
                    while ((len = inputStream.read(data)) != -1) { 
                        String message = new String(data, 0, len);
                        System.out.println("客户端传来消息: " + message);
                    }
                }
            } catch (IOException e) { 
                e.printStackTrace();
            }
        }
    }

import java.io.IOException;
    import java.net.Socket;
    
    /** * @author 闪电侠 */
    public class Client { 
        private static final String HOST = "127.0.0.1";
        private static final int PORT = 10000;
        private static final int SLEEP_TIME = 5000;
    
        public static void main(String[] args) throws IOException { 
            final Socket socket = new Socket(HOST, PORT);
    
            new Thread(() -> { 
                System.out.println("客户端启动成功!");
                while (true) { 
                    try { 
                        String message = "hello world";
                        System.out.println("客户端发送数据: " + message);
                        socket.getOutputStream().write(message.getBytes());
    
                    } catch (Exception e) { 
                        System.out.println("写数据出错!");
                    }
                    sleep();
                }
            }).start();
        }
    
        private static void sleep() { 
            try { 
                Thread.sleep(SLEEP_TIME);
            } catch (InterruptedException e) { 
                e.printStackTrace();
            }
        }
    }