Spring is generating CSRF token per request instead of per session, want to generate per session

Question

I am using spring security to generate CSRF token and send it over to client in Cookie. Currently the token is getting changed after every request but I want spring to generate a single token for the whole session. I am not sure if this is because of my code. Here is my code :

protected static class SecurityConfiguration extends WebSecurityConfigurerAdapter {
  @Override
  protected void configure(HttpSecurity http) throws Exception {
    http
      .httpBasic().and()
      .authorizeRequests()
        .antMatchers("/**").permitAll().and().
         .csrf().csrfTokenRepository(csrfTokenRepository()).and()
      .addFilterAfter(new CsrfHeaderFilter(), CsrfFilter.class);
  }

private CsrfTokenRepository csrfTokenRepository() {
  HttpSessionCsrfTokenRepository repository = new HttpSessionCsrfTokenRepository();
  repository.setHeaderName("X-XSRF-TOKEN");
  return repository;
}
}

This is my filter :

public class CsrfHeaderFilter extends OncePerRequestFilter {
  @Override
  protected void doFilterInternal(HttpServletRequest request,
      HttpServletResponse response, FilterChain filterChain)
      throws ServletException, IOException {
    CsrfToken csrf = (CsrfToken) request.getAttribute(CsrfToken.class
        .getName());
    if (csrf != null) {
      Cookie cookie = WebUtils.getCookie(request, "XSRF-TOKEN");
      String token = csrf.getToken();
      if (cookie==null || token!=null && !token.equals(cookie.getValue())) {
        cookie = new Cookie("XSRF-TOKEN", token);
        cookie.setPath("/");
        response.addCookie(cookie);
      }
    }
    filterChain.doFilter(request, response);
  }
}