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一、TCP协议实现网络通信

public class TCPServer {       //端口号    private static final int port = 9002;    public static void main(String[] args) throws IOException {           //1.创建TCP服务器端        ServerSocket serverSocket = new ServerSocket(port);        System.out.println("服务器启动成功！");        //2.等待客户端的连接.连接起来就可以进行交互        Socket client =  serverSocket.accept();//会返回socket对象        //连接起来就可以进行交互        System.out.println(String.format("有客户端连接了，客户端IP:%s  端口：%d",                    client.getInetAddress().getHostAddress(),client.getPort()));        //try-resource：JVM可以自动关闭资源        try( BufferedReader bufferedReader = new BufferedReader(                new InputStreamReader(client.getInputStream())        );             BufferedWriter bufferedWriter = new BufferedWriter(                     new OutputStreamWriter(client.getOutputStream())             )        ){               while (true){   //可能有多个消息                //3.接收客户端的信息                String msg = bufferedReader.readLine();                if (msg != null && !msg.equals("")) {                       System.out.println("收到客户端信息：" + msg);                }                //4.返回给客户端的响应信息                String serMsg = "我收到了！";                bufferedWriter.write(serMsg+"\n");//!!!!!!!!!!!!!!!!!!!!!!+\n                //刷新缓冲区                bufferedWriter.flush();            }        }    }}

客户端：

public class TCPClient {       //服务器端的IP    private static final String ip = "127.0.0.1";    //服务器端口号    private static final int port = 9002;    public static void main(String[] args) throws IOException {           //1.创建TCP客户端--》同时连接到服务器端        Socket socket = new Socket(ip,port);        try(BufferedReader bufferedReader = new BufferedReader(                new InputStreamReader(socket.getInputStream()));            BufferedWriter bufferedWriter = new BufferedWriter(                    new OutputStreamWriter(socket.getOutputStream()));            Scanner scanner = new Scanner(System.in);            ){               while (true){   //不停的进行信息写入                System.out.print("->");                String msg = scanner.nextLine();                //2.发送信息                bufferedWriter.write(msg+"\n");                bufferedWriter.flush();                //3.接收服务端返回的信息                String serMsg = bufferedReader.readLine();                System.out.println("服务器端反馈："+serMsg);                //刷新缓冲区                bufferedWriter.flush();            }        }    }}

二、基于TCP实现英译汉程序

public class TCPServerByCN {       private static final int port = 9003;    //定义翻译字典    static HashMap
   
     dirMap = new HashMap<>();    //在项目运行之后    static {           dirMap.put("hello","你好");        dirMap.put("cat","猫");        dirMap.put("dog","狗");    }    public static void main(String[] args) throws IOException {           //1.创建TCP服务器        ServerSocket serverSocket = new ServerSocket(port);        System.out.println("英译汉服务器已启动~");        //2.等待客户端连接        Socket client = serverSocket.accept();        System.out.println(String.format("有客户端连接了，客户端IP:%s  端口：%d",                client.getInetAddress().getHostAddress(),client.getPort()));        try(                BufferedReader bufferedReader = new BufferedReader(                        new InputStreamReader(client.getInputStream()));                BufferedWriter bufferedWriter = new BufferedWriter(                        new OutputStreamWriter(client.getOutputStream()))        ) {               while (true){   //循环接收                //3.得到客户端的英文单词                String en = bufferedReader.readLine();                if(en!=null && !en.equals("")){                       //4.英译汉的结果处理方法                    String cn =  processData2(en);                    //5.将结果返回给客户端                    bufferedWriter.write(cn+"\n");                    //刷新                    bufferedWriter.flush();                }            }        }    }    /**【方式1】     * 穷举法---实现英译汉     * @param en     * @return     */    private static String processData(String en) {           String cn ="未知";        switch (en){               case "hello":                cn = "你好";                break;            case "cat":                cn = "猫";                break;            case "dog":                cn = "狗";                break;            default:                break;        }        return cn;    }    /**【方式1】     * HashMap---实现英译汉     * @param en     * @return     */    private static String processData2(String en){           //todo:扩展英译汉项目2021.4.14：数据库➕爬虫        String cn ="未知";        cn=dirMap.get(en);        return cn;    }}
   

客户端代码略。