import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.Socket;

//Inner Class 사용해서 구현
//Clientsend
//ClientReceive

public class Ex04_TCP_Chat_Client {
	public static void main(String[] args) {
		Ex04_TCP_Chat_Client client = new Ex04_TCP_Chat_Client();
	}
	
	Socket socket = null;
	public Ex04_TCP_Chat_Client() {
		try {
			socket = new Socket("192.168.0.39", 9999);
			System.out.println("서버와 연결 되었습니다");
			
			new ClientSend().start();
			new ClientReceive().start();
		}catch(Exception e) {
			System.out.println(e.getMessage());
		}
	}
	
	class ClientSend extends Thread {
		@Override
		public void run() {
			BufferedReader br = null;
			PrintWriter pw = null;
			try {
				br = new BufferedReader(new InputStreamReader(System.in));
				pw = new PrintWriter(socket.getOutputStream(), true);
				
				while(true) {
					String data = br.readLine();
					if(data.equals("exit")) break;
					pw.println(data);
				}
				System.out.println("client send 작업 종료");
			}catch (Exception e) {
				System.out.println(e.getMessage());
			}
		}
	}
		
	class ClientReceive extends Thread {
		@Override
		public void run() {		
			BufferedReader br = null;
			try {
				br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
				String data = null;
				while((data = br.readLine()) != null) {
					System.out.println("Server로부터 받은 메시지 [ " + data + " ]");
				}
				System.out.println("ClientReceive 종료");
			}catch (Exception e) {
				System.out.println(e.getMessage());
			}finally {
				try {
					br.close();
				}catch (Exception e) {
					System.out.println(e.getMessage());
				}
			}
		}
	}
}

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

//Echo: 순차적인 데이터 처리 (Ex01 ~ Ex03)

//Server: read, write
//Client: read, write
//동시에 (Thread) ...
//read (Thread) >> stack, write (Thread) >> stack

//1:1 채팅은 입력과 출력이 동시에...
public class Ex04_TCP_Chat_Server {
	public static void main(String[] args) {
		ServerSocket serversocket = null;

		try {
			serversocket = new ServerSocket(9999);
			System.out.println("접속 대기중...");
			Socket socket = serversocket.accept(); //클라이언트가 접속을 하면
			System.out.println("연결완료");

			//ServerSend 객체나
			//ServerReceive 객체나 socket 객체의 주소가 필요
			//WHY?: socket을 통해서 read, write

			//ServerSend send = new ServerSend(socket);
			//send.start();
			new ServerSend(socket).start();

			//ServerReceive receive = new ServerReceive();
			//receive.start();
			new ServerReceive(socket).start();

		}catch (Exception e) {
			System.out.println(e.getMessage());
		}finally {
			try {
				serversocket.close();
			}catch (Exception e) {
				System.out.println(e.getMessage());
			}
		}
	}
}

//고민: socket (read, write 객체)
//Write: socket > outputStream
class ServerSend extends Thread {
	//cmd 창에서 입력한 값을 read해서
	//OutputStream 사용해서 write >> 연결된 socket을 통해서
	Socket socket;
	public ServerSend(Socket socket) {
		this.socket = socket;
	}

	@Override
	public void run() { //다른 stack main 함수와 같은 역할
		BufferedReader br = null;
		PrintWriter pw = null;
		try {
			/*
			Scanner sc = new Scanner(System.in);
			String msg = sc.nextLine();
			OutputStream out = socket.getOutputStream();
			DataOutputStream dos = new DataOutputStream(out);
			dos.writeUTF(msg);
			*/

			//Buffer >> Line() read
			br = new BufferedReader(new InputStreamReader(System.in));
			// InputStreamReader(System.in)은 Scanner(System.in) 역할을 한다
			pw = new PrintWriter(socket.getOutputStream(), true); // true하면 자동 flush()

			while(true) {
				String data = br.readLine(); //sc.nextline() 역할
				if(data.equals("exit")) break;
				pw.println(data); //접속한 클라이언트에게 메시지 전송 dos.writeUTF(msg) 역할
			}
			System.out.println("server send 작업 종료");
		}catch (Exception e) {
			System.out.println(e.getMessage());
		}finally {
			try {
				pw.close();
				br.close();
			}catch(Exception e) {
				System.out.println(e.getMessage());
			}
		}
	}
}

//Read: socket > inputStream
class ServerReceive extends Thread {
	//연결된 socket을 통해서 read해서
	//cmd 그 결과를 출력
	Socket socket;
	public ServerReceive(Socket socket) {
		this.socket = socket;
	}
	@Override
	public void run() {
		BufferedReader br = null;
		try {
			/*
			InputStream in = socket.getInputStream();
			DataInputStream dis = new DataInputStream(in);
			String msg = dis.readUTF();
			*/
			br = new BufferedReader(new InputStreamReader(socket.getInputStream()));
			String data = null;
			while((data = br.readLine()) != null) {
				System.out.println("Client로부터 받은 메시지 [ " + data + " ]");
			}
			System.out.println("ServerReceive 종료");
		}catch (Exception e) {
			System.out.println(e.getMessage());
		}finally {
			try {
				br.close();
			}catch (Exception e) {
				System.out.println(e.getMessage());
			}
		}
	}
}