public String getSuccessUrl() {
        return successUrl;
    }
Returns the application's after-login success URL to be assigned to all acquired Filters that subclass
{@link AuthenticationFilter} or {@code null} if no value should be assigned globally. The default value
is {@code null}.

@return the application's after-login success URL to be assigned to all acquired Filters that subclass
{@link AuthenticationFilter} or {@code null} if no value should be assigned globally.
@see #setSuccessUrl
support/spring/src/main/java/org/apache/shiro/spring/web/ShiroFilterFactoryBean.java