protected String getName() {
        if (this.name == null) {
            FilterConfig config = getFilterConfig();
            if (config != null) {
                this.name = config.getFilterName();
            }
        }

        return this.name;
    }
Returns the filter's name.
<p/>
Unless overridden by calling the {@link #setName(String) setName(String)} method, this value defaults to the
filter name as specified by the servlet container at start-up:
<pre>
this.name = {@link #getFilterConfig() getFilterConfig()}.{@link FilterConfig#getFilterName() getName()};</pre>

@return the filter name, or {@code null} if none available
@see javax.servlet.GenericServlet#getServletName()
@see javax.servlet.FilterConfig#getFilterName()
web/src/main/java/org/apache/shiro/web/servlet/NameableFilter.java