controller.java

The Software cannot constitute the primary value of any new software derived from or incorporating

        }

        UserInfo uInfo;
        try
        {
            uInfo = validateUser( username, password );
            if( !uInfo.userValid )
            {
                out.print( SEPARATOR + "Error: invalid username and/or password." );
                return;
            }
        }
        catch( SQLException e )
        {
            out.print( SEPARATOR + "Error: server-side database error." );
            return;
        }

        if( !database.markTaskDone( taskId ) )
        {
            out.print( SEPARATOR + "Error: Task marking failed." );
        }
        else
        {
            out.print( SEPARATOR + "OK" );
        }
    }

    /**
     * Implements the DeleteUser action. Tries to remove the user from the
     * database.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doDeleteUserAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        String userId = (String) request.getParameter( "user_id" );

        request.getSession( false ).setAttribute( "sqlError", null );

        if( !database.deleteUser( userId ) )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "An SQL error occurred while modifying a user." );
        }

        return "/main.jsp";
    }

    /**
     * Implements the SaveUser action. Saves modified user data into the
     * database.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doSaveUserAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        String login = (String) request.getParameter( "user" );
        String pw = (String) request.getParameter( "pw" );
        String mobile = (String) request.getParameter( "phone" );
        String groupId = (String) request.getParameter( "group" );
        String userId = (String) request.getParameter( "user_id" );

        request.getSession( false ).setAttribute( "sqlError", null );

        if( !database.changeUser( login, pw, mobile, groupId, userId ) )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "An SQL error occurred while modifying a user." );
        }

        return "/main.jsp";
    }

    /**
     * Implements the AddNewUser action. Adds a new row to the user table in the
     * database.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doAddNewUserAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        String login = (String) request.getParameter( "user" );
        String pw = (String) request.getParameter( "pw" );
        String mobile = (String) request.getParameter( "phone" );
        String group = (String) request.getParameter( "group" );

        request.getSession( false ).setAttribute( "sqlError", null );

        if( !database.addNewUser( login, pw, mobile, group ) )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "An SQL error occurred while adding a user." );
        }

        return "/main.jsp";
    }

    private String doSetServerinfoAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        String address = (String) request.getParameter( "address" );
        String port = (String) request.getParameter( "port" );

        request.getSession( false ).setAttribute( "sqlError", null );

        if( !database.setServerInfo( address, port ) )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "An SQL error occurred while adding a server info." );
        }
		
		return "/main.jsp";
    }
	
	
    /**
     * Implements the Error action. Sets the request attribute "loginError" so
     * that an error message can be seen on the login screen.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doErrorAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        request.setAttribute( "loginError", "Error: Not logged in" );
        return "/index.jsp";
    }
	
    /**
     * Implements the AddNewTask action. Adds a new row to the task table.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doAddNewTaskAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        String oldDescription = (String) request.getParameter( "description" );
        String owner_id = (String) request.getParameter( "owner" );
        String state = (String) request.getParameter( "state" );
        String description = null;

        request.getSession( false ).setAttribute( "sqlError", null );
        if( ( description = oldDescription.replace( '#', ' ' ) ) != oldDescription )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "#-characters are illegal and were removed." );
        }

        if( !database.addNewTask( owner_id, description, state ) )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "An SQL error occurred while adding a task." );
        }

        return "/main.jsp";
    }

    /**
     * Implements the ChangePassword action. Changes the users password in the
     * database.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doChangePasswordAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        String currentPw = (String) request.getParameter( "currentpw" );
        String newPw = (String) request.getParameter( "pw" );
        String userId = (String) request.getSession( false ).getAttribute(
                "userId" );

        request.getSession( false ).setAttribute( "sqlError", null );

        if( database.checkCurrentPassword( currentPw, userId ) )
        {
            if( !database.changePassword( newPw, userId ) )
            {
                request.getSession( false ).setAttribute( "sqlError",
                        "An SQL error occurred while changing password." );
            }
            else
            {
                request.getSession( false ).setAttribute( "sqlError",
                        "Password changed succesfully." );
            }
        }
        else
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "Current password was incorrect." );
        }

        return "/main.jsp";
    }

    /**
     * Implements the DeleteTask action. Removes the specified task from the
     * task table.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doDeleteTaskAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        String taskId = (String) request.getParameter( "taskId" );
        String ownerId = (String) request.getParameter( "owner" );

        request.getSession( false ).setAttribute( "sqlError", null );

        if( !database.deleteTask( taskId, ownerId ) )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "An SQL error occurred while deleting a task." );
        }

        return "/main.jsp";
    }

    /**
     * This function implements the login actions. It makes sure the inserted
     * username and password are of valid format and can be found from the
     * database. It also sets up the necessary session attributes.
     * 
     * @param request
     *            Request received from the client.
     * @param response
     *            Response to the client.
     * @return A string depicting the name of the page to be shown next.
     * @throws ServletException
     * @throws IOException
     */
    private String doLoginAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        // Form data is extracted.
        String username = request.getParameter( "username" );
        String password = request.getParameter( "password" );
		
		System.out.println("username: " +username +" password: " +password);
        UserInfo uInfo;

        // The field must not be empty.
        if( username == null || password == null || username == ""
                || password == "" )
        {
            request.setAttribute( "loginError",
                    "Error: username and/or password not provided." );
            return "/index.jsp";
        }
        // If true, the servlet couldn't connect to the database when
        // initialized
        else if( databaseNotInUse )
        {
            request.setAttribute( "loginError",
                    "Database connection couldn't be formed" );
            return "/index.jsp";
        }

        try
        {
            uInfo = validateUser( username, password );
        }
        catch( SQLException e )
        { // Something went wrong when communicating with the database.
            request.setAttribute( "loginError",
                    "An error occured while communicating with the database." );
            return "/index.jsp";
        }

        if( !uInfo.userValid )
        { // The received username and password couldn't be found from the
            // database.
            request.setAttribute( "loginError", "Invalid username or password" );
            return "/index.jsp";
        }
        // A new session is created.
        HttpSession userSession = request.getSession( true );

        userSession.setAttribute( "userId", uInfo.userId );
        userSession.setAttribute( "userRole", uInfo.userRole );
        userSession.setAttribute( "username", username );

        // The client is redirected to the main page after a succesful login.
        return "/main.jsp";
    }

    /**
     * Implements the Logout action. Invalidates the session and returns the
     * client to the login screen.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doLogoutAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        request.getSession( false ).invalidate();
        return "/index.jsp";

    }

    /**
     * Implements the SaveTask action.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doSaveTaskAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        String oldDescription = (String) request.getParameter( "description" );
        String taskId = (String) request.getParameter( "taskId" );
        String ownerId = (String) request.getParameter( "owner" );
        String state = (String) request.getParameter( "state" );
        String description = null;

        request.getSession( false ).setAttribute( "sqlError", null );
        if( ( description = oldDescription.replace( '#', ' ' ) ) != oldDescription )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "#-characters are illegal and were removed." );
        }

        if( !database.changeTask( ownerId, description, state, taskId ) )
        {
            request.getSession( false ).setAttribute( "sqlError",
                    "An SQL error occurred while modifying a task." );
        }

        return "/main.jsp";
    }

    /**
     * Implements the SendSMS action.
     * 
     * @param request
     *            The request object from the servlet.
     * @param response
     *            The response object from the servlet.
     * @return The page to be shown next.
     */
    private String doSendSMSAction( HttpServletRequest request,
            HttpServletResponse response )
    {
        request.setAttribute( "smsSent", "true" );

        return "/main.jsp";
    }

    /**
     * This function validates the username and password by accessing the
     * database.
     * 
     * @param username
     *            The username to be checked.
     * @param password
     *            The password to be checked.
     * @return A boolean value depending on wether the username and password
     *         were accepted.
     * @throws SQLException
     *             Thrown if an error occurred while communicating with the
     *             database.
     */
    private UserInfo validateUser( String username, String password )
            throws SQLException
    {
        if( username.length() > 20 || password.length() > 20 )
        {
            return new UserInfo( false );
        }

        // The user login is authenticated.
        UserInfo uInfo = database.validateUser( username, password );

        return uInfo;
    }
}