[TCP/IP]소켓을 이용한 EchoServer

EchoServer 란 ?

- 클라이언트가 전송해 준 데이터를 받고 받은 데이터를 그대로  클라이언트에게 전송해주는 서버

package socket2.test;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.io.PrintWriter;
import java.net.ServerSocket;
import java.net.Socket;

public class server2 {
	
	ServerSocket server = null;
	int port = 54;
	Socket socket = null;
	
	InputStream inputstream = null;
	InputStreamReader streamreader = null;
	BufferedReader buffer = null;
	
	OutputStream outputstream = null;
	OutputStreamWriter streamwriter = null;
	BufferedWriter bufferwriter = null;
	
	PrintWriter pw = null;
	String receiveMsg = null;     //Client의 받은 문자열 저장
	
	
   /** 
    * 
    * @throws IOException 예외 던진다 
    *  ServerStart() 호출한 다른 메소드에게 예외 던져짐
    */
	public void ServerStart() throws IOException{
				
		try {
				server = new ServerSocket(port);
				while(true){
					System.out.println("-- 접속 대기 --");
					socket = server.accept(); //클라이언트가 접속 소켓반환
					System.out.println(socket.getInetAddress() + "로 부터 연결요청이 들어옴");
					
					receiveData();
					
					ServerStop();
					sendStop();
					
			}
		}
				catch (Exception e) {
					e.printStackTrace();
					ServerStop();
				}			
		}
		public void ServerStop() throws IOException {
			
			inputstream.close();
			streamreader.close();
			buffer.close();
			server.close();
			
		}
		
		public void receiveData() throws IOException {

				try {
					inputstream = socket.getInputStream();
					streamreader = new InputStreamReader(inputstream);
					buffer = new BufferedReader(streamreader);
					
					outputstream = socket.getOutputStream();
					streamwriter = new OutputStreamWriter(outputstream);
					pw = new PrintWriter(new OutputStreamWriter(outputstream));
				        bufferwriter = new BufferedWriter(streamwriter);

					while((receiveMsg = buffer.readLine() ) != null) {
						
						System.out.println("Client로부터 받은 문자열:" + receiveMsg);
						pw.println(receiveMsg); //받은메시지 출력
						pw.flush(); //버퍼 비움
					}
			
					

		}
				catch (Exception e) {
					e.printStackTrace();
					ServerStop();
				}
	}
		
		public void sendStop() throws IOException {
				bufferwriter.close();
				streamwriter.close();
				outputstream.close();
                                               pw.close();		
		}
		
		public static void main(String[] args) throws IOException{
			
			server2 serverstart = new server2();
			
			serverstart.ServerStart();
		
		
		}

}