前面我们讲了基于UDP的网络编程

UDP回显服务器 

UDP字典服务器 

下面我们来讲基于TCP的回显服务编写

1、服务器

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;public class Server {private static ServerSocket socket = null;public Server(int port) throws IOException {socket = new ServerSocket(port);}public static void start() throws IOException {System.out.println("服务器端启动！");//使用多线程的方式，可以与多个客户端连接while (true){Socket clientSocket = socket.accept();Thread thread = new Thread(()->{try {procession(clientSocket);} catch (IOException e) {throw new RuntimeException(e);}});thread.start();}}public static void procession(Socket clientSocket) throws IOException {System.out.printf("[%s:%d] 客户端上线！",clientSocket.getInetAddress(),clientSocket.getPort());System.out.println();//TCP使用的是I/O流try (InputStream inputStream = clientSocket.getInputStream();OutputStream outputStream = clientSocket.getOutputStream();){while (true){Scanner scanner = new Scanner(inputStream);if (!scanner.hasNext()){System.out.printf("[%s:%d] 客户端下线",clientSocket.getInetAddress(),clientSocket.getPort());System.out.println();break;}String request = scanner.next();String response = process(request);PrintWriter writer = new PrintWriter(outputStream);writer.println(response);writer.flush();System.out.printf("[%s:%d] req:%s,resp:%s",clientSocket.getInetAddress().toString(),clientSocket.getPort(),request,response);System.out.println();}}catch (IOException e){e.printStackTrace();}finally {try {clientSocket.close();}catch (IOException e){e.printStackTrace();}}}public static String process(String request){return request;}public static void main(String[] args) throws IOException {Server server = new Server(9090);server.start();}
}

2、客户端

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 Client {public static Socket socket = null;public Client(String ip,int port) throws IOException {socket = new Socket(ip,port);}public static void start() throws IOException {System.out.println("客户端启动！");Scanner scanner = new Scanner(System.in);try (InputStream inputStream = socket.getInputStream();OutputStream outputStream = socket.getOutputStream()){PrintWriter writer = new PrintWriter(outputStream);Scanner scannerRes = new Scanner(inputStream);while (true){System.out.print("->");String request = scanner.next();writer.println(request);writer.flush();String response = scannerRes.next();System.out.println(response);}}catch (IOException e){e.printStackTrace();}}public static void main(String[] args) throws IOException {Client client = new Client("127.0.0.1",9090);client.start();}}

最终结果