How to skip a filter in the filter chain in java

Question

Hi All,

I have 2 filters in my application. Based on some condition, I want to choose whether to execute the second filter or not. Is there a way to do this?

I did some googling with no success. I want the request to continue without executing the second filter. Is that possible?

Any help will be appreciated.

Answer 1

You can set an Attribute in your request and check it in your second filter.

public class FirstFilter implements Filter {
    //...

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        servletRequest.setAttribute("executeSecondFilter", true);
        //...
        if(someReason)
            servletRequest.setAttribute("executeSecondFilter", false);
        filterChain.doFilter(servletRequest, servletResponse);
    }
}

public class SecondFilter implements Filter {
    //..

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        if (servletRequest.getAttribute("executeSecondFilter") == null || !((Boolean) servletRequest.getAttribute("executeSecondFilter"))) {
            filterChain.doFilter(servletRequest, servletResponse);
        }
        //...
    }
}

---

You can simplify the code above like this :

public class FirstFilter implements Filter {
    //...

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        //...
        if(someReason)
            servletRequest.setAttribute("executeSecondFilter", false);
        filterChain.doFilter(servletRequest, servletResponse);
    }
}

public class SecondFilter implements Filter {
    //..

    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        if (servletRequest.getAttribute("executeSecondFilter") != null) {
            filterChain.doFilter(servletRequest, servletResponse);
        }
        //...
    }
}

This way you just check the presence of the attribute "executeSecondFilter"

Answer 2

In addition to Colin's answer, there's another way: just don't call FilterChain#doFilter(), but RequestDispatcher#forward().

if (condition) {
    request.getRequestDispatcher(((HttpServletRequest) request).getServletPath()).forward(request, response);
} else {
    chain.doFilter(request, response);
}

But this will skip all filters from current on, expect of the ones which are listening on <dispatcher>FORWARD</dispatcher>.