org.jasig.cas.client校驗

##AbstractTicketValidationFilter org.jasig.cas.client.validation.AbstractTicketValidationFilter

public final void doFilter(final ServletRequest servletRequest, final ServletResponse servletResponse,
            final FilterChain filterChain) throws IOException, ServletException {

        if (!preFilter(servletRequest, servletResponse, filterChain)) {
            return;
        }

        final HttpServletRequest request = (HttpServletRequest) servletRequest;
        final HttpServletResponse response = (HttpServletResponse) servletResponse;
        final String ticket = retrieveTicketFromRequest(request);

        if (CommonUtils.isNotBlank(ticket)) {
            logger.debug("Attempting to validate ticket: {}", ticket);

            try {
                final Assertion assertion = this.ticketValidator.validate(ticket,
                        constructServiceUrl(request, response));

                logger.debug("Successfully authenticated user: {}", assertion.getPrincipal().getName());

                request.setAttribute(CONST_CAS_ASSERTION, assertion);

                if (this.useSession) {
                    request.getSession().setAttribute(CONST_CAS_ASSERTION, assertion);
                }
                onSuccessfulValidation(request, response, assertion);

                if (this.redirectAfterValidation) {
                    logger.debug("Redirecting after successful ticket validation.");
                    response.sendRedirect(constructServiceUrl(request, response));
                    return;
                }
            } catch (final TicketValidationException e) {
                logger.debug(e.getMessage(), e);

                onFailedValidation(request, response);

                if (this.exceptionOnValidationFailure) {
                    throw new ServletException(e);
                }

                response.sendError(HttpServletResponse.SC_FORBIDDEN, e.getMessage());

                return;
            }
        }

        filterChain.doFilter(request, response);

    }

##AuthenticationFilter org.jasig.cas.client.authentication.AuthenticationFilter

public final void doFilter(final ServletRequest servletRequest, final ServletResponse servletResponse,
            final FilterChain filterChain) throws IOException, ServletException {
        
        final HttpServletRequest request = (HttpServletRequest) servletRequest;
        final HttpServletResponse response = (HttpServletResponse) servletResponse;
        
        if (isRequestUrlExcluded(request)) {
            logger.debug("Request is ignored.");
            filterChain.doFilter(request, response);
            return;
        }
        
        final HttpSession session = request.getSession(false);
        final Assertion assertion = session != null ? (Assertion) session.getAttribute(CONST_CAS_ASSERTION) : null;

        if (assertion != null) {
            filterChain.doFilter(request, response);
            return;
        }

        final String serviceUrl = constructServiceUrl(request, response);
        final String ticket = retrieveTicketFromRequest(request);
        final boolean wasGatewayed = this.gateway && this.gatewayStorage.hasGatewayedAlready(request, serviceUrl);

        if (CommonUtils.isNotBlank(ticket) || wasGatewayed) {
            filterChain.doFilter(request, response);
            return;
        }

        final String modifiedServiceUrl;

        logger.debug("no ticket and no assertion found");
        if (this.gateway) {
            logger.debug("setting gateway attribute in session");
            modifiedServiceUrl = this.gatewayStorage.storeGatewayInformation(request, serviceUrl);
        } else {
            modifiedServiceUrl = serviceUrl;
        }

        logger.debug("Constructed service url: {}", modifiedServiceUrl);

        final String urlToRedirectTo = CommonUtils.constructRedirectUrl(this.casServerLoginUrl,
                getProtocol().getServiceParameterName(), modifiedServiceUrl, this.renew, this.gateway);

        logger.debug("redirecting to \"{}\"", urlToRedirectTo);
        this.authenticationRedirectStrategy.redirect(request, response, urlToRedirectTo);
    }

##filter執行順序 先AbstractTicketValidationFilter後AuthenticationFilter。即先看有沒ticket，有的話，去跟cas server驗證，驗證成功則往下，不成功則跳轉到cas/login。若是沒有ticket則往下驗證有沒有session，有的成功，沒有則跳轉到cas請求service ticket。 ##doc

• cas-client-core
• Filter的執行順序與實例
• CasClientConfiguration