Programming are endless.

import java.io.InputStream;
import java.io.OutputStream;
import java.net.Socket;

public class SocketClient {

	// 접속 시도하려는 IP, 포트번호 입력
	public SocketClient(String host, int port) {
		try {
			Socket socket = new Socket(host, port);
			OutputStream os = socket.getOutputStream();
			os.write("Hello".getBytes());
			
			InputStream is = socket.getInputStream();
			byte[] b = new byte[10240];
			int readCount = is.read(b);
			System.out.println(new String(b, 0, readCount));
			
			os.write("Hello".getBytes());
			readCount = is.read(b);
			
			
		} catch (Exception e) {
			e.printStackTrace();
		}
	}
	
}