• CalcServer

package ch04_quiz;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.ServerSocket;
import java.net.Socket;

/*
 * 클라이언트가 서버로 보낸 데이터를 서버가 받아서 더하는 코드를 작성하세요
 * 클라이언트로 부터 -(minus) 값이 전송되면 계산을 멈추고 종료합니다
 */

public class CalcServer {
	
	public static void main(String[] args) {
		ServerSocket listener = null;
		Socket socket = null;
		BufferedReader sin = null;
		BufferedWriter sout = null;
		
		
		
		try {
			listener = new ServerSocket(10000);
			System.out.println("--- Calc Server ---");
			socket = listener.accept();
			sin = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			sout = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
			
			int res = 0;
			int num1 = 0;
			int num2 = 0;
			int operater = 0;
			while(true) {
				// 2. 클라이언트에서 값 수신
				num1 = sin.read();
				num2 = sin.read();
				operater = sin.read();
				
				// while문 종료구문 
				if(num1<0 | num2<0) {
					System.out.println("- 연결 종료 -");
					break;
				}
				
				// 3. 계산 및 데이터 클라이언트에게 전송.
				switch(operater) {
				case 1:
					res = num1+num2;
					break;
				case 2:
					res = num1-num2;
					break;
				case 3:
					res = num1*num2;
					break;
				case 4:
					res = num1/num2;
					break;
				}

				sout.write(res);
				sout.flush();
			}
			
			
		} catch (Exception e) {
			System.out.println("서버 error");
		} finally {
			try {
				if(sin != null) sin.close();
				if(sout != null) sout.close();
				if(socket != null) socket.close();
				if(listener != null) listener.close();
			} catch (Exception e2) {
				e2.printStackTrace();;
			}
		}
		
		
	} // main
	
	int Calc() {
		return 0;
	}
}

• CalcClient

package ch04_quiz;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.InputStreamReader;
import java.io.OutputStreamWriter;
import java.net.Socket;
import java.util.Scanner;

public class CalcClient {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		Socket socket = null;
		BufferedReader cin = null;
		BufferedWriter cout = null;
		
		try {
			socket = new Socket("localhost",10000);
			System.out.println("서버 연결...");
			
			cin = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			cout = new BufferedWriter(new OutputStreamWriter(socket.getOutputStream()));
			
			int num1 = 0;
			int num2 = 0;
			int operator = 0;
			while(true) {
				// 0. 값 입력
				System.out.print("num1 > ");
				num1 = sc.nextInt();
				System.out.print("num2 > ");
				num2 = sc.nextInt();
				System.out.print("operator 1.+ 2.- 3.* 4./ >");
				operator = sc.nextInt();
				
				// while문 종료구문 
				if(num1 < 0 | num2 <0) {
					break;
				}
				
				// 1. 서버에 값 송신
				cout.write(num1);
				cout.write(num2);
				cout.write(operator);
				cout.flush();
				System.out.println();
				
				// 4. 서버에서 값 수신 및 출력 
				short result = (short) cin.read();
				System.out.println("result : " + result);
				System.out.println();
			}
			
		} catch (Exception e) {
			System.out.println("클라이언트 error");
		} finally {
			try {
				if(cin != null) cin.close();
				if(cout != null) cout.close();
				if(socket != null) socket.close();
				if(sc != null) sc.close();
			} catch (Exception e2) {
				e2.printStackTrace();
			}
		}
		
	}
}