[ Java ] Socket 實作猜數字小游戲！！！

記一次作業

運行截圖

• Server
  
• Client
  

完整代碼

• Server

import java.io.IOException;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.Random;
import java.util.Scanner;

public class ServerDemo {
    private int flag;

    public void server() throws IOException {
        //創建一個服務器
        System.out.println("服務端啟動，等待客戶端連接，，，");
        PrintWriter out = null;
        Scanner getClient = null;
        ServerSocket server = null;
        Socket client = null;
        this.setFlag();
        try {
            server = new ServerSocket(6666);
            //創建一個接收連接客戶端的物件
            client = server.accept();
            System.out.println(client.getInetAddress() + " 已成功連接到此臺服務器上，");
            //字符輸出流
            out = new PrintWriter(client.getOutputStream());    //向客戶端發送資料
            out.println("歡迎來到猜數字小游戲（1-100）！！！");
            out.flush();//將緩沖流中的資料全部輸出
            getClient = new Scanner(client.getInputStream());  //接收客戶端發送的資料
            //阻塞等待客戶端發送訊息過來
            while (getClient.hasNextLine()) {
                String returnMsg = null;
                String tmp = getClient.nextLine();
                if ("e".equals(tmp)) {
                    break;
                } else if ("c".equals(tmp)) {
                    returnMsg = "歡迎來到新一輪的猜數字小游戲（1-100）！！！";
                    this.setFlag();
                } else {
                    int clientInput = Integer.parseInt(tmp);

                    if (clientInput > flag) {
                        returnMsg = "你輸入的數字大了！！！";
                    } else if (clientInput < flag) {
                        returnMsg = "你輸入的數字小了！！！";
                    } else {
                        returnMsg = "恭喜你，猜中了！！！繼續（輸入c）,退出（輸入e）";
                    }
                }
                out.println(returnMsg); //向客戶端發送資料
                out.flush();
            }
        } catch (IOException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            out.close();
            getClient.close();
            server.close();
        }
    }

    // 生成亂數字
    public void setFlag() {
        Random r = new Random();
        flag = r.nextInt(100);
        System.out.println("猜數字小游戲答案：flag = " + flag);
    }

    public static void main(String[] args) throws IOException {
        new ServerDemo().server();
    }
}

• Client

import java.io.IOException;
import java.io.PrintWriter;
import java.net.Socket;
import java.util.Scanner;

public class ClientDemo {

    public void client() throws IOException {
        System.out.println("正在向服務器請求連接，，，");
        Socket client = null;
        Scanner getKey = null;
        Scanner getServer = null;
        PrintWriter out = null;
        try {
            client = new Socket("127.0.0.1", 6666);
            getServer = new Scanner(client.getInputStream());
            System.out.println(getServer.nextLine());
            out = new PrintWriter(client.getOutputStream());
            System.out.print("請輸入數字：");
            //先讀取鍵盤錄入方可向服務端發送訊息
            getKey = new Scanner(System.in);
            while (getKey.hasNextLine()) {
                //寫到服務端的的控制臺
                out.println(getKey.nextLine());
                out.flush();
                try {
                    System.out.println("提示訊息：" + getServer.nextLine());
                    System.out.print("請輸入數字：");
                } catch (Exception e) {
                    System.out.print("游戲結束！！！");
                    break;
                }
                //阻塞等待接收服務端的訊息
            }
        } catch (Exception e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        } finally {
            getKey.close();
            getServer.close();
            out.close();
            client.close();
        }

    }

    public static void main(String[] args) throws IOException {
        new ClientDemo().client();
    }
}