/src/ChatAppServer/EchoServer.java

  1package ChatAppServer;
  2import java.io.*;
  3import java.net.*;
  4
  5
  6public class EchoServer {
  7
  8	/**
  9	 * Manages accounts for chat clients that connect to it. Communication is handled
 10	 * through the following textual protocol:
 11	 * 
 12	 * FORMAT:
 13	 * 	<ACTION>
 14	 * 		Send:
 15	 * 			<VERB> [<DATA> | <DATA>... ] <TERMINATOR>
 16	 * 		Recieve:
 17	 * 			<VERB> [<DATA> | <DATA>... ] <TERMINATOR>
 18	 * 
 19	 * PROTOCOL SPECIFICATION:
 20	 * 	<LOGIN>
 21	 * 		Send:
 22	 * 			LOGIN <USERNAME> <PASSWORD>\n\n
 23	 * 		Recieve:
 24	 * 			LOGIN_SUCCESS\n\n
 25	 * 			or
 26	 * 			LOGIN_FAIL\n\n
 27	 * 
 28	 *  <CHECK USERNAME>
 29	 * 		Send:
 30	 * 			CHECK_USER <USERNAME>\n\n
 31	 * 		Recieve:
 32	 * 			USER_OK\n\n
 33	 * 			or
 34	 * 			USER_TAKEN\n\n
 35	 * 
 36	 *  <CREATE ACCOUNT>
 37	 * 		Send:
 38	 * 			CREATE_USER <USERNAME> <PASSWORD> <EMAIL>\n\n
 39	 * 		Recieve:
 40	 * 			USER_SUCCESS\n\n
 41	 * 			or
 42	 * 			USER_FAIL\n\n
 43	 * 
 44	 *  <CHECK ONLINE>
 45	 * 		Send:
 46	 * 			IS_ONLINE <USERNAME>\n\n
 47	 * 		Recieve:
 48	 * 			TRUE\n\n
 49	 * 			or
 50	 * 			FALSE\n\n
 51	 * 
 52	 *  <SET OFFLINE>
 53	 * 		Send:
 54	 * 			LOGOFF <USERNAME>\n\n
 55	 * 		Recieve:
 56	 * 			No response
 57	 * 
 58	 *  <GET IP>
 59	 * 		Send:
 60	 * 			GET_IP <USERNAME>\n\n
 61	 * 		Recieve:
 62	 * 			<IP>\n\n
 63	 * 			or
 64	 * 			FAIL\n\n
 65	 * 
 66	 * @param args
 67	 */
 68	public static void main(String[] args) throws IOException {
 69		// Create our account database
 70		db = new AccountDB();
 71		
 72		// Declare a Socket to bind to.
 73		ServerSocket sockem = null;
 74		
 75		// Bind to port 4444
 76		sockem = new ServerSocket(4444);
 77		
 78		try {
 79			while (true) {
 80				// Blocks until client connects
 81				System.out.println("Waiting for Client...");
 82				Socket rockem = sockem.accept();
 83				
 84				// Client connected
 85				System.out.println("Client " + rockem.getInetAddress().toString() + " connected on PORT: " + rockem.getLocalPort());
 86				System.out.println("Starting new thread to handle client...");
 87				
 88				Runnable r = new ClientHandler(rockem, db);
 89				Thread clientHandlerThread = new Thread(r);
 90				clientHandlerThread.start();
 91			}
 92		} catch (Exception e) {
 93			e.printStackTrace();
 94		}
 95		
 96		// Close the server socket and release the port
 97		sockem.close();
 98	}
 99	
100	private static AccountDB db;
101}