login/logout

 //FAZER LOGIN
	public String login( String username, String password) throws RemoteException{

		int check=0;
		String resultado;
		//-----------------------------------
		//Verificar se o login pode ser feito
		//-----------------------------------
		Statement myStmt;
		try {

			myStmt = myConn.createStatement();

			ResultSet myRs = myStmt.executeQuery("SELECT USERNAME, PASSWORD\n"
												+ "FROM users\n"
												+ "WHERE USERNAME ='"+username+"' AND PASSWORD = '"+password+"'");//results set

			if(myRs.next()){


				check = 0;
				String sql = "UPDATE users\n "
	                       + "SET ONLINE = 1\n"
	                       + "WHERE USERNAME ='"+username+"' AND PASSWORD = '"+password+"' ";
				myStmt.executeUpdate(sql); //results set



			}else{
				check =1;

			}
		} catch (SQLException e) {
			check =1;
			e.printStackTrace();
		}
		if(check ==0){
			resultado = "type: login, ok: true";
		}else{
			resultado = "type: login, ok: false";
		}
		return resultado;

	}

	//LOGOUT
	public void logout(String username) throws RemoteException{


		//-----------------------------------
		//LOGOUT
		//-----------------------------------
		Statement myStmt;
		try {

			myStmt = myConn.createStatement();

			String sql = "UPDATE users\n "
	                      + "SET ONLINE = 0\n"
	                      + "WHERE USERNAME ='"+username+"'";
			myStmt.executeUpdate(sql); //results set

		} catch (SQLException e) {

			e.printStackTrace();
		}


	}