package javaNet_TCP; import java.io.BufferedReader; import java.io.BufferedWriter; import java.io.IOException; import java.io.InputStreamReader; import java.io.OutputStreamWriter; import java.net.ServerSocket; import java.net.Socket; import java.nio.charset.StandardCharsets; import java.time.LocalDateTime; public class TCPServer { public static void main(String[] args) throws Exception { ServerSocket ss = new ServerSocket(9090); System.out.println("TCP server ready."); Socket sock = ss.accept();//返回新建立的客户端连接 try (BufferedReader reader = new BufferedReader( new InputStreamReader(sock.getInputStream(), StandardCharsets.UTF_8))){ try (BufferedWriter writer = new BufferedWriter(new OutputStreamWriter(sock.getOutputStream()))){ String cmd = reader.readLine(); if ("time".equals(cmd)){ writer.write(LocalDateTime.now().toString()+"\n"); writer.flush(); } else { writer.write("Sorry?\n"); writer.flush();//以流的形式先写入缓存区，满了才发送到网络上，使用flush强制发送 } } } sock.close(); ss.close(); } }