11.소켓과 스레드의 결합

여러 클라이언트가 접속가능한 서버

EchoServerReceiveThread.java

public class EchoServer {
	private static final int SERVER_PORT = 5000;
	public static void main(String[] args) {
		ServerSocket serverSocket = null;
		try {
			// 1. 서버 소켓 생성
			serverSocket = new ServerSocket();

			// 2. 바인딩( Binding )
			InetAddress inetAddress = InetAddress.getLocalHost();
			String localhostAddress = inetAddress.getHostAddress();

			serverSocket.bind(new InetSocketAddress(localhostAddress, SERVER_PORT));
			System.out.println("[Server] binding " + localhostAddress);

			while(true) {
			// 3. 연결 요청 기다림( accept)
			Socket socket = serverSocket.accept(); // 반복문 내에서 blocking이 되기떄문에 CPU를 많이먹지 않는다.
			new EchoServerReceiveThread( socket ).start();
			}

		}
			catch (IOException e) { // 서버소켓과 관련된 캐치
			e.printStackTrace();
		} finally {
			try {
				if (serverSocket != null && serverSocket.isClosed() == false) {
					serverSocket.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	private static void consoLog( String log ) {
		System.out.println( "[server:" );

	}
}

EchoServerReceiveThread.java

public class EchoServerReceiveThread extends Thread {
	private Socket socket;
	public EchoServerReceiveThread( Socket socket ) {
		this.socket = socket;
	}
	@Override
	public void run() {
		// 4. 연결성공
		InetSocketAddress remoteSocketAddress = (InetSocketAddress) socket.getRemoteSocketAddress();

		int remoteHostPort = remoteSocketAddress.getPort();
		String remoteHostAddress = remoteSocketAddress.getAddress().getHostAddress();
		consoleLog("connected from "+ remoteHostAddress);
		try {
			// 5. I/O Stream 받아오기
			InputStream is = socket.getInputStream();

			BufferedReader br = new BufferedReader(new InputStreamReader(is, "UTF-8"));

			PrintWriter pw = new PrintWriter(socket.getOutputStream(), true);
			// auto flush를 true로 한다. true로 안하면
			// 버퍼가 다찬다음 나가기 때문에 늦게나간다.
			while (true) {
				// 6. 데이터 읽기
				String message = br.readLine();

				if (message == null) { // 정상종료
					consoleLog("disconnection by client");
					break;
				}

				consoleLog(" received : " + message);

				// 7. 데이터 쓰기
				pw.println(message);
			}

		} catch (SocketException e) {
			// 상대편이 소켓을 정상적으로 닫지 않고 종료한 경우
			consoleLog("sudden closed by client");

		} catch (IOException e) { // 소켓과 관련된 캐치
			e.printStackTrace();
		} finally {
			try {
				if (socket != null && socket.isClosed() == false) {
					socket.close();
				}
			} catch (IOException e) {
				e.printStackTrace();
			}
		}
	}
	private void consoleLog(String log) {
		System.out.println("[Server: "+getId() + "]" + log);

	}

}