is Spring Security custom login method cancels redirec?

So basiclly redirect to /index.xhtml doesn't work after login. I can't figure out how to fix it but I think what is the problem with my code, if someone could help I'd be glad.

I have login() method, which in my opinion lacks something:

public String login() {
        try {
            Authentication request = new UsernamePasswordAuthenticationToken(this.getUsername(), this.getPassword());
            Authentication result = authenticationManager.authenticate(request);
        SecurityContextHolder.getContext().setAuthentication(result);
    } catch (BadCredentialsException badCredentialsException) {
        //handle exception
    } catch (DisabledException disabledException) {
        //handle exception
    }
    return "loggedin";
}

Also in my securityContext:

<sec:http auto-config="true" use-expressions="true" request-matcher="regex" create-session="always">
    <access-denied-handler error-page="/?accessDenied=true"/>
    <form-login login-page="/login.xhtml" default-target-url="/index.xhtml" always-use-default-target="true"/>
    <logout invalidate-session="true" delete-cookies="true" logout-success-url="/"/>
</sec:http>

Am I right that redirect doesn't work is because I have custom login method that doesn't use the .xml settings? How can I fix that?

EDIT:

<h:form prependId="false">
<h:panelGroup id="loginRender" layout="block">
    <h:panelGroup layout="block">
        <h:inputText id="j_username" required="true" value="#{loginBean.username}"></h:inputText>
        <h:outputText value="LOGIN"></h:outputText>
        <h:inputSecret id="j_password" required="true" value="#{loginBean.password}"></h:inputSecret>
        <h:outputText value="PASSWORD"></h:outputText>

        <h:commandButton id="login_button" value="LOG IN" action="#{loginBean.login}"> <!-- Login button, with login() action -->
        </h:commandButton>
    </h:panelGroup>
</h:panelGroup>