个人主页User_芊芊君子欢迎大家点赞评论收藏⭐文章系列专栏JavaEE文章目录摘要代码示例约定好协议请求Request:响应Response:服务器:客户端:总结摘要只懂协议理论不动手等于没学。本文基于 Java TCPSocket从零实现一个网络版计算器约定运算符操作数的请求格式与运算结果的响应格式完成 Request/Response 的序列化与反序列化服务端用线程池支持多客户端并发客户端从控制台循环读取输入。文末附完整可运行代码与运行效果图。代码示例约定好协议明确传递的数据请求运算符±*/操作数响应运算结果组织传输数据格式自定义文本格式请求运算符操作数1操作数\n响应结果\n请求Request:package application; //表示一个请求 public class Request { private String operator; private double num1; private double num2; public Request(String operator, double num1, double num2) { this.operator operator; this.num1 num1; this.num2 num2; } //对象--字符串 public String covertToString(){ //String.format():类似printf但只是构造到String中没有打印 return String.format(%s,%f,%f\n,operator,num1,num2); } public static Request convertFromString(String request){ //1.获取参数 String[] split request.split(,);//切分 String opertor split[0]; double num1 Double.parseDouble(split[1]);//字符串转成double double num2 Double.parseDouble(split[2]); //2.创建对象 return new Request(opertor,num1,num2); } public String getOperator() { return operator; } public double getNum1() { return num1; } public double getNum2() { return num2; } }响应Response:package application; public class Response { private double result; Response(double result){ this.result result; } //转换成字符串 public String convertToString(){ return String.format(%f\n,result); } //把字符串转换成对象 public static Response convertFromString(String response){ double result Double.parseDouble(response); return new Response(result); } public double getResult() { return result; } }服务器:package application; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintWriter; import java.net.ServerSocket; import java.net.Socket; import java.util.Scanner; import java.util.concurrent.ExecutorService; import java.util.concurrent.Executors; public class TcpCalcServer { private ServerSocket serverSocket null; public TcpCalcServer(int port)throws IOException{ serverSocket new ServerSocket(port); } public void start() throws IOException{ System.out.println(服务器启动); ExecutorService service Executors.newCachedThreadPool(); while (true){ Socket socket serverSocket.accept(); service.submit(()-{ try { processConnection(socket); } catch (IOException e) { throw new RuntimeException(e); } }); } } private void processConnection(Socket socket) throws IOException { System.out.printf([%s:%d 客户端上线],socket.getInetAddress().toString(),socket.getPort()); try (InputStream inputStream socket.getInputStream(); OutputStream outputStream socket.getOutputStream()){ Scanner scanner new Scanner(inputStream); PrintWriter printWriter new PrintWriter(outputStream); while (true){ //1.读取请求并解析 if (!scanner.hasNext()){ break; } String requestString scanner.next(); //反序列化 Request request Request.convertFromString(requestString); //2.根据请求计算响应 Response response process(request); //3.把响应写回客户端 String responseString response.convertToString(); //构造String时已经带了\n,直接print写入即可 printWriter.print(responseString); printWriter.flush(); } }catch (IOException e){ e.printStackTrace(); }finally { System.out.printf([%s:%d] 客户端下线!\n,socket.getInetAddress().toString(),socket.getPort()); socket.close(); } } private Response process(Request request) { //根据参数和运算符完成计算构造响应 if(request.getOperator().equals()){ return new Response(request.getNum1() request.getNum2()); }else if(request.getOperator().equals(-)){ return new Response(request.getNum1() - request.getNum2()); }else if(request.getOperator().equals(*)){ return new Response(request.getNum1() * request.getNum2()); }else if(request.getOperator().equals(/)){ return new Response(request.getNum1() / request.getNum2()); }else { throw new RuntimeException(不支持的运算符request.getOperator()); } } public static void main(String[] args) throws IOException { TcpCalcServer server new TcpCalcServer(9090); server.start(); } }客户端:package application; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.io.PrintWriter; import java.net.Socket; import java.util.Scanner; public class TcpCalcClient { private Socket socket null; public TcpCalcClient(String serverIp,int serverPort) throws IOException { socket new Socket(serverIp,serverPort); } public void start(){ System.out.println(客户端运行中); try (InputStream inputStream socket.getInputStream(); OutputStream outputStream socket.getOutputStream()){ Scanner scannerConsole new Scanner(System.in); Scanner scannerNetwork new Scanner(inputStream); PrintWriter printWriter new PrintWriter(outputStream); while (true){ //1.从控制台读取用户输入内容 System.out.println(请输入要进行的运算 - * /); String operator scannerConsole.next(); System.out.println(请输入第一个数字); double num1 scannerConsole.nextDouble(); System.out.println(请输入第二个数字); double num2 scannerConsole.nextDouble(); //2.构造请求并发送 Request request new Request(operator,num1,num2); String requsetString request.covertToString(); printWriter.println(requsetString); printWriter.flush(); //3.读取服务器响应结果 if(!scannerNetwork.hasNext()){ break; } String responseString scannerNetwork.next(); Response response Response.convertFromString(responseString); //4.打印响应结果 System.out.println(response.getResult()); } }catch (IOException e){ e.printStackTrace(); } } public static void main(String[] args) throws IOException { TcpCalcClient client new TcpCalcClient(127.0.0.1,9090); client.start(); } }总结一个标准的网络程序 协议设计 序列化/反序列化 Socket 收发循环。服务端固定 accept → 读请求 → 算响应 → 写回的流程客户端则是 构造请求 → 发送 → 等响应 → 展示。多客户端并发借助线程池即可实现。这套骨架就是以后写任何 TCP业务服务端的模板。