org.glassmaker.forge/org.glassmaker.spring.oauth2/src/main/java/org/glassmaker/spring/oauth/OAuth2EntryPoint.java
public void commence(HttpServletRequest req, HttpServletResponse resp, AuthenticationException authException) throws IOException, ServletException {

		String redirectUrl = null;
		logger.debug("No auth context found. Kicking off a new auth flow.");

		AuthorizationCodeFlow flow = oAuth2Util.newAuthorizationCodeFlow();
		GenericUrl url = flow.newAuthorizationUrl().setRedirectUri(getCallbackUrl());
		url.set("approval_prompt", "force");
		redirectUrl = url.build();
		redirectStrategy.sendRedirect(req, resp, redirectUrl);

	}
public void commence(HttpServletRequest req, HttpServletResponse resp, AuthenticationException authException) throws IOException, ServletException {

		String redirectUrl = null;
		logger.debug("No auth context found. Kicking off a new auth flow.");

		AuthorizationCodeFlow flow = oAuth2Util.newAuthorizationCodeFlow();
		GenericUrl url = flow.newAuthorizationUrl().setRedirectUri(getCallbackUrl());
		url.set("approval_prompt", "force");
		redirectUrl = url.build();
		redirectStrategy.sendRedirect(req, resp, redirectUrl);

	}
Performs the redirect (or forward) to the login form URL.