how to configure Spring boot, Apache Shiro, bujipac4j for SAML SSO

Question

I have a Spring Boot - Theme Leaf - Shiro Application

I Have seen examples for following

1. Spring boot - spring-security - pac4j-saml sso https://github.com/pac4j/spring-security-pac4j-boot-demo

2. Shiro web application - buji-pac4j https://github.com/pac4j/buji-pac4j-demo

What i want to do is to have best of the both worlds. I want to use Shiro for RBAC, and use buji-pac4j for authentication, to authenticate via SAML SSO.

I dont find any documentation to achieve the same. Following is what i have done, please guide in my setting this up properly.

//in WebConfig .java i have following

public class WebConfig extends WebMvcConfigurerAdapter {
   @Bean("samlConfig")
    public Config config() {
        final SAML2Configuration  cfg = new SAML2Configuration ("resource:samlKeystore.jks",
                "pac4j-demo-passwd",
                "pac4j-demo-passwd",
                "resource:metadata-okta.xml");
        cfg.setMaximumAuthenticationLifetime(3600);
        cfg.setServiceProviderEntityId("https://localhost/callback?client_name=SAML2Client");
        cfg.setServiceProviderMetadataPath("sp-metadata.xml");
        cfg.setAuthnRequestBindingType(SAMLConstants.SAML2_REDIRECT_BINDING_URI);       


        final SAML2Client saml2Client = new SAML2Client(cfg);
        final Clients clients = new Clients("https://localhost/callback", saml2Client);

        final Config config = new Config(clients);
        config.addAuthorizer("custom", new CustomAuthorizer());  // this same as in example buji-pac4j-demo
        return config;
    }
}

//In WebSecurityConfig.java i have following

public class WebSecurityConfig {

@Autowired
    private Config samlConfig;   

    @Bean(name = "shiroFilter")
    public AbstractShiroFilter shiroFilter() throws Exception {
        ShiroFilterFactoryBean shiroFilterFactoryBean = new ShiroFilterFactoryBean();

        HashMap<String, String> filterChainDefinitionMapping = new HashMap<String,String>();
        filterChainDefinitionMapping.put("/*", "anon");
        filterChainDefinitionMapping.put("/login", "anon");  
        filterChainDefinitionMapping.put("/forgotPwd", "anon");
        filterChainDefinitionMapping.put("/resetPwd", "anon");       
        filterChainDefinitionMapping.put("/logout", "logout");
        filterChainDefinitionMapping.put("/**", "authc,ssl");

        shiroFilterFactoryBean.setFilterChainDefinitionMap(filterChainDefinitionMapping);
        shiroFilterFactoryBean.setSecurityManager(securityManager());

        final SecurityFilter bujiFilter = new SecurityFilter();
        bujiFilter.setConfig(samlConfig);
        bujiFilter.setClients("Saml2Client");

        HashMap<String, Filter> filters = new HashMap<>();
        filters.put("anon", new AnonymousFilter());

        filters.put("authc", bujiFilter);

        LogoutFilter logoutFilter = new LogoutFilter();
        logoutFilter.setRedirectUrl("/logout");       
        filters.put("logout", logoutFilter);

        filters.put("roles", new RolesAuthorizationFilter());
        filters.put("user", new UserFilter());
        shiroFilterFactoryBean.setFilters(filters);

        return (AbstractShiroFilter) shiroFilterFactoryBean.getObject();
    }
     /* i was previously using Shiro Authentication, hence the below code is there , now i want to do SAML SSO*/

    @Bean(name = "customRealm")
    @DependsOn("lifecycleBeanPostProcessor")     
    public CustomRealm customRealm() {
        CustomRealm realm = new CustomRealm();

        HashedCredentialsMatcher credentialsMatcher = new HashedCredentialsMatcher();
        credentialsMatcher.setHashAlgorithmName(Sha256Hash.ALGORITHM_NAME);
        credentialsMatcher.setStoredCredentialsHexEncoded(false);       
        credentialsMatcher.setHashSalted(true);
        realm.setCredentialsMatcher(credentialsMatcher);

        realm.init();
        return realm;
    }

    @Bean(name = "securityManager")
    public DefaultWebSecurityManager securityManager() {
        DefaultWebSecurityManager securityManager = new DefaultWebSecurityManager();
        securityManager.setRealm(customRealm());
        return securityManager;
    }

}

Now when i access any protected resource for e.g https://localhost/protected/home instead of taking me to the IDP login (okta), like in the example of https://github.com/pac4j/buji-pac4j-demo ; the app redirects to default Shiro Auth url https://localhost/login.jsp

What am i missing here,is my config in the shiroFilter wrong? if so what is the correct way ?