EchoServer

服务端程序：

import java.io.IOException;
import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Scanner;

public class EchoServer {
    public static void main(String[] args) throws IOException {
        ServerSocket serverSocket = new ServerSocket(8000);//设置服务监听端口
        System.out.println("等待客户端连接...");//打印提示信息
        Socket clientSocket = serverSocket.accept();//等待客户端连接
        Scanner scanner = new Scanner(clientSocket.getInputStream());//客户端输入流
        scanner.useDelimiter("\n");//设置分隔符
        PrintStream outPrintStream = new PrintStream(clientSocket.getOutputStream());//客户端输出流
        boolean flag = true;//循环标记
        while (flag) {
            if(scanner.hasNext()) {//有数据接收
                String string = scanner.next().trim();//接收数据内容
                if("bye".equalsIgnoreCase(string)) {//结束标记
                    outPrintStream.println("Bye!");//回应信息
                    flag = false;//结束循环
                }else {
                    outPrintStream.println("[ECHO]" + string);//Echo信息
                }
            }
        }
        scanner.close();//关闭输入流
        outPrintStream.close();//关闭输出流
        clientSocket.close();//关闭客户端
        serverSocket.close();//关闭服务端
    }
}

客户端程序：

package SocketDemo;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintStream;
import java.net.Socket;
import java.util.Scanner;

public class EchoClient {
    private static final BufferedReader KEYBOARD_INPUT = new BufferedReader(new InputStreamReader(System.in));
    public static String getString(String prompt) throws Exception{//键盘信息输入
        System.out.print(prompt);
        String string = KEYBOARD_INPUT.readLine();
        return string;
    }
    
    public static void main(String[] args) throws Exception{
        Socket clientSocket = new Socket("localhost", 8000);//定义服务端的连接信息
        //现在的客户端需要有输入与输出的操作支持，所以依然要准备Scanner与PrintWriter
        Scanner scanner = new Scanner(clientSocket.getInputStream());//接收服务端输入内容
        scanner.useDelimiter("\n");
        PrintStream outputPrintStream = new PrintStream(clientSocket.getOutputStream());//向服务端发送内容
        boolean flag = true;//循环标记
        while(flag) {//循环处理
            String inputString = getString("请输入内容：").trim();//获取键盘输入数据
            outputPrintStream.println(inputString);//加换行
            if(scanner.hasNext()) {//服务器端有回应
                System.out.println(scanner.next());//输出回应信息
            }
            if("bye".equalsIgnoreCase(inputString)) {//结束判断
                flag = false;//修改循环标记
            }
        }
        scanner.close();//关闭输入流
        outputPrintStream.close();//关闭输出流
        clientSocket.close();//关闭客户端
    }
}